Publications by authors named "Luigina Spaccini"

36 Publications

L1CAM variants cause two distinct imaging phenotypes on fetal MRI.

Ann Clin Transl Neurol 2021 Sep 12. Epub 2021 Sep 12.

Neuroradiology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.

Data on fetal MRI in L1 syndrome are scarce with relevant implications for parental counseling and surgical planning. We identified two fetal MR imaging patterns in 10 fetuses harboring L1CAM mutations: the first, observed in 9 fetuses was characterized by callosal anomalies, diencephalosynapsis, and a distinct brainstem malformation with diencephalic-mesencephalic junction dysplasia and brainstem kinking. Cerebellar vermis hypoplasia, aqueductal stenosis, obstructive hydrocephalus, and pontine hypoplasia were variably associated. The second pattern observed in one fetus was characterized by callosal dysgenesis, reduced white matter, and pontine hypoplasia. The identification of these features should alert clinicians to offer a prenatal L1CAM testing.
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http://dx.doi.org/10.1002/acn3.51448DOI Listing
September 2021

Autosomal Dominant Hypophosphatemic Rickets: A Case Report and Review of the Literature.

Int J Environ Res Public Health 2021 08 19;18(16). Epub 2021 Aug 19.

Department of Pediatrics, V. Buzzi Children's Hospital, Università di Milano, Via Lodovico Castelvetro, 32, 20154 Milan, Italy.

Autosomal dominant hypophosphatemic rickets (ADHR) is an extremely rare form of genetic rickets caused by mutations in the fibroblast growth factor 23 gene. ADHR is characterized by hypophosphatemia secondary to isolated renal phosphate wasting. Only a few cases of ADHR have been reported in the literature to date. We describe the case of a 17-month-old girl who presented with severe failure to thrive (length: -4.08 standard deviation (SD), weight: -2.2 SD) and hypotonia. Hypophosphatemia, decreased tubular phosphate reabsorption (69%), and rachitic lesions were found. Genetic analysis showed the heterozygous variant c.536G>A (NM_020638.3:c.536G>A) in exon 3 of the FGF23 gene, leading to the diagnosis of ADHR. She was treated with phosphate salts and oral alfacalcidol. After 4 years of treatment, at 5 years of age, the patient's ADHR resolved spontaneously. Considering the lack of knowledge regarding ADHR, we reviewed the literature to describe the features of this rare and poorly understood disease. Eleven ADHR pediatric cases have been described thus far, with cases tending to be more common in females than males. Similar to the general population, two groups of patients with ADHR can be described depending on the mutations present: patients with an R179 and R176 mutation have early-onset of disease and higher frequency of rickets, and a milder and late-onset of disease, respectively. Symptoms and disease severity may fluctuate. Spontaneous remission may occur during the pediatric age.
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http://dx.doi.org/10.3390/ijerph18168771DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8392413PMC
August 2021

Neonatal Dyshormonogenetic Goiter with Hypothyroidism Associated with Novel Mutations in Thyroglobulin and SLC26A4 Gene.

Pediatr Rep 2021 May 2;13(2):210-215. Epub 2021 May 2.

Pediatric Unit, Department of Pediatrics, "Vittore Buzzi" Children's Hospital, 20154 Milan, Italy.

Congenital goiter is an uncommon cause of neck swelling and it can be associated with hypothyroidism. We discuss a case of primary hypothyroidism with goiter presenting at birth. Ultrasound showed the enlargement of the gland and thyroid function tests detected marked hypothyroidism. Genetic analysis via next generation sequencing (NGS) was performed finding two mutations associated with thyroid dyshormonogenesis: c.7813 C > T, homozygous in the exon 45 of the thyroglobulin gene (TG) and c.1682 G > A heterozygous in exon 15 of the SLC26A4 gene (pendrin). Sanger sequencing of parents' DNA samples revealed that the first mutation (c.7813 C > T) was inherited from both of them, while the second one (c.1682 G > A) was inherited from the mother. Hormone replacement therapy was started, following which a gradual decrease in the size of the goiter was seen with the normalization of hormonal levels. Normal infant growth status and neurological development were recorded during follow-up. Neonatal dyshormonogenetic goiter with hypothyroidism may represent an unusual cause of neonatal neck mass. Early identification and hormone replacement therapy are crucial for a better neurodevelopmental outcome. Genetic analysis is mandatory in order to reach a specific diagnosis and to elucidate new patterns of thyroid disorder.
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http://dx.doi.org/10.3390/pediatric13020029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8163152PMC
May 2021

Electroclinical features of MEF2C haploinsufficiency-related epilepsy: A multicenter European study.

Seizure 2021 May 30;88:60-72. Epub 2021 Mar 30.

Maternal and Pediatric Department, Fondazione IRCCS Casa Sollievo della Sofferenza, Poliambulatorio "Giovanni Paolo II", Viale Padre Pio, snc, San Giovanni Rotondo (FG) 71013, Italy.

Purpose: Epilepsy is a main manifestation in the autosomal dominant mental retardation syndrome caused by heterozygous variants in MEF2C. We aimed to delineate the electro-clinical features and refine the genotype-phenotype correlations in patients with MEF2C haploinsufficiency.

Methods: We thoroughly investigated 25 patients with genetically confirmed MEF2C-syndrome across 12 different European Genetics and Epilepsy Centers, focusing on the epileptic phenotype. Clinical features (seizure types, onset, evolution, and response to therapy), EEG recordings during waking/sleep, and neuroimaging findings were analyzed. We also performed a detailed literature review using the terms "MEF2C", "seizures", and "epilepsy".

Results: Epilepsy was diagnosed in 19 out of 25 (~80%) subjects, with age at onset <30 months. Ten individuals (40%) presented with febrile seizures and myoclonic seizures occurred in ~50% of patients. Epileptiform abnormalities were observed in 20/25 patients (80%) and hypoplasia/partial agenesis of the corpus callosum was detected in 12/25 patients (~50%). Nine patients harbored a 5q14.3 deletion encompassing MEF2C and at least one other gene. In 7 out of 10 patients with myoclonic seizures, MIR9-2 and LINC00461 were also deleted, whereas ADGRV1 was involved in 3/4 patients with spasms.

Conclusion: The epileptic phenotype of MEF2C-syndrome is variable. Febrile and myoclonic seizures are the most frequent, usually associated with a slowing of the background activity and irregular diffuse discharges of frontally dominant, symmetric or asymmetric, slow theta waves with interposed spike-and-waves complexes. The haploinsufficiency of ADGRV1, MIR9-2, and LINC00461 likely contributes to myoclonic seizures and spasms in patients with MEF2C syndrome.
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http://dx.doi.org/10.1016/j.seizure.2021.03.025DOI Listing
May 2021

Efficacy of Everolimus Low-Dose Treatment for Cardiac Rhabdomyomas in Neonatal Tuberous Sclerosis: Case Report and Literature Review.

Pediatr Rep 2021 Mar 1;13(1):104-112. Epub 2021 Mar 1.

Pediatric Cardiology Unit, "Vittore Buzzi" Children's Hospital, 20154 Milano, Italy.

: Cardiac rhabdomyomas (CRs) are the most common cardiac tumors in newborns. Approximately 80-90% of cases are associated with tuberous sclerosis complex (TSC). In selective cases, Everolimus has resulted in a remarkable tumoral regression effect in children with TS. The optimal dosage for neonates is still unknown. : We describe the use of Everolimus in a neonate with multiple biventricular CRs, causing subaortic obstruction, in which a low-dose treatment (0.1 mg/die), in an effort to maintain serum trough levels of 3-7 ng/mL, was successfully used off-label, without adverse effects. : We showed that a low-dose Everolimus regimen may be an effective and safe treatment for CR regression in TS neonates, when the minimum therapeutic range was maintained.
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http://dx.doi.org/10.3390/pediatric13010015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7931111PMC
March 2021

Spinal cord involvement and paroxysmal events in "Infantile Onset Transient Hypomyelination" due to TMEM63A mutation.

J Hum Genet 2021 Mar 30. Epub 2021 Mar 30.

COALA (Center for diagnosis and treatment of leukodystrophies), V. Buzzi Children's Hospital, Milano, Italy.

Monoallelic mutations on TMEM63A have been recently reported as cause of a previously unrecognized disorder named "infantile-onset transient hypomyelination". Clinical and neuroradiological presentation is described as highly similar to Pelizaeus-Merzbacher Disease but evolution over time was surprisingly benign with a progressive spontaneous improving course. We report on a new TMEM63A-mutated girl. The clinical picture was similar to the one already described except for the presence of recurrent episodes of unilateral eyelid twitching, and for the evidence of spinal cord involvement on MRI. These are interesting findings helping in distinguishing this condition from classic PMD since early disease stages. However, additional observations are needed to confirm if these are common features of this condition.
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http://dx.doi.org/10.1038/s10038-021-00921-1DOI Listing
March 2021

CD10 and CD34 as markers in vascular malformations with PIK3CA and TEK mutations.

Hum Pathol 2020 05 6;99:98-106. Epub 2020 Apr 6.

Unit of Human Pathology, Department of Health Sciences, Santi Paolo e Carlo Hospital Medical School, University of Milan, Milan, 20142, Italy.

Aims: Vascular malformations (vMs) encompass a wide range of diseases often associated with somatic or, more rarely, germinal genetic mutations. A mutation in the PIK3Ca/mTOR pathway is more often involved in various vMs. CD10 and CD34 are cellular markers that may play a role in mesenchymal differentiation and proliferation. The aim of our study was to find a possible link between the immunohistochemical expression of CD10 and CD34 in vMs and their relationship with mutations in the PIK3CA/mTOR signaling pathway.

Methods And Results: Our study on 58 samples of vMs showed that in endothelial cells, CD10 was significantly expressed in PIK3CA-mutated samples compared with samples without any mutation (p < 0.05), especially and even more consistently when compared with samples with mutation in other pathways (p < 0.0001). Conversely, in the same PIK3CA-mutated samples, CD34 expression in endothelial cells was significantly reduced compared with samples either without any mutation or mutations in other pathways (p < 0.05 and p < 0.0005). Compared with samples with mutations in other pathways, a significant overexpression of endothelial CD10 was also found in samples with TEK/TIE2 mutation, a gene linked to the PIK3CA/mTOR pathway (p < 0.01). However, CD34 expression was not altered. In samples with PIK3CA mutation, the CD10 expression was significantly increased in the stroma compared with samples with TEK/TIE2 gene or other gene mutations (p < 0.05).

Conclusion: Therefore, the CD10 and CD34 immunohistochemical profile could suggest/support the presence of mutations in the PIK3CA/mTOR pathway in samples of vMs.
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http://dx.doi.org/10.1016/j.humpath.2020.04.001DOI Listing
May 2020

De novo EIF2AK1 and EIF2AK2 Variants Are Associated with Developmental Delay, Leukoencephalopathy, and Neurologic Decompensation.

Am J Hum Genet 2020 04 19;106(4):570-583. Epub 2020 Mar 19.

Stanford Center for Undiagnosed Diseases, Stanford University, Stanford, CA 94305, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA.

EIF2AK1 and EIF2AK2 encode members of the eukaryotic translation initiation factor 2 alpha kinase (EIF2AK) family that inhibits protein synthesis in response to physiologic stress conditions. EIF2AK2 is also involved in innate immune response and the regulation of signal transduction, apoptosis, cell proliferation, and differentiation. Despite these findings, human disorders associated with deleterious variants in EIF2AK1 and EIF2AK2 have not been reported. Here, we describe the identification of nine unrelated individuals with heterozygous de novo missense variants in EIF2AK1 (1/9) or EIF2AK2 (8/9). Features seen in these nine individuals include white matter alterations (9/9), developmental delay (9/9), impaired language (9/9), cognitive impairment (8/9), ataxia (6/9), dysarthria in probands with verbal ability (6/9), hypotonia (7/9), hypertonia (6/9), and involuntary movements (3/9). Individuals with EIF2AK2 variants also exhibit neurological regression in the setting of febrile illness or infection. We use mammalian cell lines and proband-derived fibroblasts to further confirm the pathogenicity of variants in these genes and found reduced kinase activity. EIF2AKs phosphorylate eukaryotic translation initiation factor 2 subunit 1 (EIF2S1, also known as EIF2α), which then inhibits EIF2B activity. Deleterious variants in genes encoding EIF2B proteins cause childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM), a leukodystrophy characterized by neurologic regression in the setting of febrile illness and other stressors. Our findings indicate that EIF2AK2 missense variants cause a neurodevelopmental syndrome that may share phenotypic and pathogenic mechanisms with CACH/VWM.
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http://dx.doi.org/10.1016/j.ajhg.2020.02.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118694PMC
April 2020

Pathogenic Variants in and in Genes for GABAa Receptor Subunities Cause Atypical Rett/Rett-like Phenotypes.

Int J Mol Sci 2019 Jul 24;20(15). Epub 2019 Jul 24.

Istituto Auxologico Italiano, IRCCS, Cytogenetics and Molecular Genetics Laboratory, 20145 Milan, Italy.

Rett syndrome (RTT) is a neurodevelopmental disorder, affecting 1 in 10,000 girls. Intellectual disability, loss of speech and hand skills with stereotypies, seizures and ataxia are recurrent features. Stringent diagnostic criteria distinguish classical Rett, caused by a pathogenic variant in 95% of cases, from atypical girls, 40-73% carrying variants, and rarely and alterations. A large fraction of atypical and RTT-like patients remain without genetic cause. Next Generation Sequencing (NGS) targeted to multigene panels/Whole Exome Sequencing (WES) in 137 girls suspected for RTT led to the identification of a de novo variant in gene in four atypical RTT and two RTT-like girls. De novo pathogenic variants-one in and, for first time, one in -were disclosed in classic and atypical RTT patients. Interestingly, the variant occurred at low rate percentage in blood and buccal swabs, reinforcing the relevance of mosaicism in neurological disorders. We confirm the role of in atypical RTT/RTT-like patients if early psychomotor delay and epilepsy before 2 years of age are observed, indicating its inclusion in the RTT diagnostic panel. Lastly, we report pathogenic variants in Gamma-aminobutyric acid-A (GABAa) receptors as a cause of atypical/classic RTT phenotype, in accordance with the deregulation of GABAergic pathway observed in defective and models.
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http://dx.doi.org/10.3390/ijms20153621DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696386PMC
July 2019

Refining the Phenotype of Recurrent Rearrangements of Chromosome 16.

Int J Mol Sci 2019 Mar 4;20(5). Epub 2019 Mar 4.

School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy.

Chromosome 16 is one of the most gene-rich chromosomes of our genome, and 10% of its sequence consists of segmental duplications, which give instability and predisposition to rearrangement by the recurrent mechanism of non-allelic homologous recombination. Microarray technologies have allowed for the analysis of copy number variations (CNVs) that can contribute to the risk of developing complex diseases. By array comparative genomic hybridization (CGH) screening of 1476 patients, we detected 27 cases with CNVs on chromosome 16. We identified four smallest regions of overlapping (SROs): one at 16p13.11 was found in seven patients; one at 16p12.2 was found in four patients; two close SROs at 16p11.2 were found in twelve patients; finally, six patients were found with atypical rearrangements. Although phenotypic variability was observed, we identified a male bias for Childhood Apraxia of Speech associated to 16p11.2 microdeletions. We also reported an elevated frequency of second-site genomic alterations, supporting the model of the second hit to explain the clinical variability associated with CNV syndromes. Our goal was to contribute to the building of a chromosome 16 disease-map based on disease susceptibility regions. The role of the CNVs of chromosome 16 was increasingly made clear in the determination of developmental delay. We also found that in some cases a second-site CNV could explain the phenotypic heterogeneity by a simple additive effect or a pejorative synergistic effect.
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http://dx.doi.org/10.3390/ijms20051095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6429492PMC
March 2019

Major Discordant Structural Anomalies in Monochorionic Twins: Spectrum and Outcomes.

Twin Res Hum Genet 2018 12 30;21(6):546-555. Epub 2018 Oct 30.

Department of Obstetrics and Gynecology,Vittore Buzzi Children's Hospital,Università di Milano,Milan,Italy.

Monochorionic twins, resulting from a single fertilized egg giving rise to two separate embryos, are monozygotic and considered genetically identical. However, discordant phenotypes have been reported in monozygotic twins. We analyzed a retrospective cohort of 155 monochorionic pregnancies (312 twins) with major discordant structural anomalies coded by the ICD-10 system in order to describe the spectrum of anomalies, the management of the pregnancies, and the perinatal outcome. Treatment options included conservative management, selective feticide with bipolar cord coagulation, or complete termination. All survivors underwent at least 24 months of postnatal follow-up. Discordancy was complicated by twin-to-twin transfusion syndrome in eight pregnancies (5%) and by selective intrauterine growth restriction in 41 (26%). Major structural anomalies affected one system in 139 cases (90%) and multiple systems in 16 (10%). Median gestational age at diagnosis was 19.1 weeks (IQR 16.4-21.3). The most frequent single-system anomalies involved the nervous and circulatory systems. In total, 72 anomalous twins (46%) and 116 normal co-twins (74%) were delivered at a median gestational age of 34.6 weeks (IQR 31.0-36.3). Neonatal/infant death of the anomalous twin occurred in 22 cases (14%), with an overall survival rate of 32% (50/155). Surviving anomalous twins underwent major surgery in 22/50 cases (44%), four of whom (8%) now suffer from severe neurologic morbidity. This study shows that a wide spectrum of major discordant structural anomalies can be found in monochorionic pregnancies. The outcome for the anomalous twin is poor, while the survival rate for the normal co-twin was 71%, with a favorable overall prognosis.
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http://dx.doi.org/10.1017/thg.2018.58DOI Listing
December 2018

Currarino syndrome and microcephaly due to a rare 7q36.2 microdeletion: a case report.

Ital J Pediatr 2018 May 25;44(1):59. Epub 2018 May 25.

Pediatric Department, "V. Buzzi" Children's Hospital, University of Milan, Via Castelvetro 32, 20154, Milan, Italy.

Background: Currarino syndrome is a rare condition characterized by presacral mass, anorectal malformation and sacral dysgenesis.

Case Presentation: We report the case of a child that presented chronic constipation, encopresis and mycrocephaly. The characteristics were initially compatible with a case of functional constipation and a therapy with polyethylene glycol was prescribed. After a year, because of poor response, a plain abdominal X-ray was performed, detecting sacrum abnormalities. Finally, a CGH-array analysis was performed and a form of Currarino Syndrome caused by a rare 7q36 microdeletion, was diagnosed.

Conclusion: Occult spinal dysraphism should be suspected in case of poor polyethylene glycol responder constipation, even when evident sacral abnormalities on the physical examination are not detected.
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http://dx.doi.org/10.1186/s13052-018-0500-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5970537PMC
May 2018

Mild ventriculomegaly from fetal consultation to neurodevelopmental assessment: A single center experience and review of the literature.

Eur J Paediatr Neurol 2018 Nov 12;22(6):919-928. Epub 2018 Apr 12.

Pediatric Neurology Unit, V. Buzzi Children's Hospital, Via Castelvetro 32, 20154 Milan, Italy.

Objective: The aim of our study was to determine the outcome of fetuses with isolated mild ventriculomegaly, with prenatal imaging work-up, prenatal consultation, delivery and clinical follow-up performed in a single tertiary referring center.

Methods: Fetuses with isolated and non-progressive mild ventriculomegaly (10-15 mm) were included in the study. Inclusion criteria were as follows: singleton pregnancies, normal chromosomal analysis, normal serological evaluation of TORCH, fetal ultrasound and MRI excluding additional CNS or extra-CNS malformations. The prenatal consultation consisted in discussing the prognosis of ventriculomegaly, according to the literature. The postnatal follow-up protocol included a neuroradiological investigation (cranial ultrasound or MRI), neurological and pediatric examinations. The Griffiths Scales were used to assess the neurodevelopmental outcome.

Results: Thirty newborns were included in follow-up. The postnatal neuroradiological investigations confirmed the ventriculomegaly as an isolated finding in all cases except one. Nineteen children were available for formal neurodevelopmental testing. In our case series, 93.3% of the children had a favorable outcome or mild anomalies. Two children (6.6%) with mild ventriculomegaly were diagnosed as having rare genetic conditions. The Griffiths developmental quotients were normal (mean General Quotient 98.3) at the latest assessment (mean age 20.8 months) in all but one case.

Discussion: Most children in our case series had a favorable outcome, as described in the literature. Even though a large quantity of data is now available on ventriculomegaly, fetal consultation remains challenging and requires caution. The diagnostic work-up of pregnancies diagnosed with mild ventriculomegaly must be very meticulous and include TORCH evaluation, microarray, serial ultrasounds to exclude progression, and a fetal MRI. However, despite accurate screening, there are more complex conditions in which ventriculomegaly can be the only non-specific finding in fetal life, making postnatal follow up mandatory.
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http://dx.doi.org/10.1016/j.ejpn.2018.04.001DOI Listing
November 2018

Phenotype and genotype of 87 patients with Mowat-Wilson syndrome and recommendations for care.

Genet Med 2018 09 4;20(9):965-975. Epub 2018 Jan 4.

Neuropsychiatric Department, Spedali Civili Brescia, Brescia, Italy.

Purpose: Mowat-Wilson syndrome (MWS) is a rare intellectual disability/multiple congenital anomalies syndrome caused by heterozygous mutation of the ZEB2 gene. It is generally underestimated because its rarity and phenotypic variability sometimes make it difficult to recognize. Here, we aimed to better delineate the phenotype, natural history, and genotype-phenotype correlations of MWS.

Methods: In a collaborative study, we analyzed clinical data for 87 patients with molecularly confirmed diagnosis. We described the prevalence of all clinical aspects, including attainment of neurodevelopmental milestones, and compared the data with the various types of underlying ZEB2 pathogenic variations.

Results: All anthropometric, somatic, and behavioral features reported here outline a variable but highly consistent phenotype. By presenting the most comprehensive evaluation of MWS to date, we define its clinical evolution occurring with age and derive suggestions for patient management. Furthermore, we observe that its severity correlates with the kind of ZEB2 variation involved, ranging from ZEB2 locus deletions, associated with severe phenotypes, to rare nonmissense intragenic mutations predicted to preserve some ZEB2 protein functionality, accompanying milder clinical presentations.

Conclusion: Knowledge of the phenotypic spectrum of MWS and its correlation with the genotype will improve its detection rate and the prediction of its features, thus improving patient care.
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http://dx.doi.org/10.1038/gim.2017.221DOI Listing
September 2018

Fetal-MRI prenatal diagnosis of severe bilateral lung hypoplasia: alveolar capillary dysplasia case report.

J Prenat Med 2016 Jul-Dec;10(3-4):15-19

Medical Genetics Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare and lethal developmental disorder of the lung that affect both acinar structure and the intrinsic pulmonary vasculature. We report prenatal and postnatal imaging with histopathological findings of this rare condition. We, first, describe MR imaging features and discuss its role in prenatal imaging.
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http://dx.doi.org/10.11138/jpm/2016.10.3.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5505476PMC
July 2017

Currarino syndrome: does the presence of a genetic anomaly correlate with a more severe phenotype? A multicentre study.

J Pediatr Surg 2017 Oct 24;52(10):1591-1596. Epub 2017 Jun 24.

Pediatric Surgery Unit, V. Buzzi Children's Hospital, Milan, Italy.

Background/purpose: Currarino syndrome (CS) phenotype, initially described as the triad of hemisacrum, anorectal malformation (ARM) and presacral mass, can be extremely variable. The triad is often incomplete and 3 main CS phenotypical subtypes have been described: Complete, Mild and Minimal. Various associated malformations are often present. Mutations in the MNX1 gene are the main genetic background of CS, although they are not present in almost half of the cases. Aim of our study is to analyze the distribution of the 3 CS subtypes and the incidence of associated malformations in a large sample of patients and to add information about the role of the genetic testing in guiding the diagnostic and prognostic evaluation of CS patients.

Methods: A multicentre retrospective data collection was performed. CS patients' phenotype was accurately analyzed according to a diagnostic-therapeutic standardized data collection sheet. The distribution of the three CS types and the frequency of each associated malformation were calculated. The phenotype of the patients with a known genetic anomaly was compared to the phenotype of the population with no genetic diagnosis, in order to determine whether the presence of a known genetic defect could correlate with a more severe CS phenotype.

Results: Data from 45 patients were analyzed. Twenty patients (44.5%) presented a Complete CS type, 19 (42.2%) a Mild CS and 6 (13.3%) a Minimal CS. In addition to the classical triad elements, 38 (84.5%) patients showed associated anomalies. The group of patients who resulted positive for a MNX1 mutation comprised a higher number (56.5%) of Complete CS cases than the group of patients that did not carry any MNX1 mutation (13%) (p = 0.0085). We could not find any relationship between CS subtype and the number of associated anomalies (p = 0.5102).

Conclusions: The presence of a MNX1 mutation seems to correlate with a more severe CS phenotype. MNX1 seems the main responsible for the expression and the severity of the CS triad, while the associated anomalies appear to be prevalently determined by genes sited on different loci. A thorough multidisciplinary diagnostic overview of CS patients should always include genetic counseling and analysis, both in postnatal and prenatal settings.

Type Of Study: Retrospective Study.

Level Of Evidence: II.
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http://dx.doi.org/10.1016/j.jpedsurg.2017.06.012DOI Listing
October 2017

Mutations in DONSON disrupt replication fork stability and cause microcephalic dwarfism.

Nat Genet 2017 Apr 13;49(4):537-549. Epub 2017 Feb 13.

Department of Pediatrics, Security Forces Hospital, Riyadh, Saudi Arabia.

To ensure efficient genome duplication, cells have evolved numerous factors that promote unperturbed DNA replication and protect, repair and restart damaged forks. Here we identify downstream neighbor of SON (DONSON) as a novel fork protection factor and report biallelic DONSON mutations in 29 individuals with microcephalic dwarfism. We demonstrate that DONSON is a replisome component that stabilizes forks during genome replication. Loss of DONSON leads to severe replication-associated DNA damage arising from nucleolytic cleavage of stalled replication forks. Furthermore, ATM- and Rad3-related (ATR)-dependent signaling in response to replication stress is impaired in DONSON-deficient cells, resulting in decreased checkpoint activity and the potentiation of chromosomal instability. Hypomorphic mutations in DONSON substantially reduce DONSON protein levels and impair fork stability in cells from patients, consistent with defective DNA replication underlying the disease phenotype. In summary, we have identified mutations in DONSON as a common cause of microcephalic dwarfism and established DONSON as a critical replication fork protein required for mammalian DNA replication and genome stability.
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http://dx.doi.org/10.1038/ng.3790DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5450907PMC
April 2017

Biallelic mutations in the 3' exonuclease TOE1 cause pontocerebellar hypoplasia and uncover a role in snRNA processing.

Nat Genet 2017 Mar 16;49(3):457-464. Epub 2017 Jan 16.

Department of Pediatrics, Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada.

Deadenylases are best known for degrading the poly(A) tail during mRNA decay. The deadenylase family has expanded throughout evolution and, in mammals, consists of 12 Mg-dependent 3'-end RNases with substrate specificity that is mostly unknown. Pontocerebellar hypoplasia type 7 (PCH7) is a unique recessive syndrome characterized by neurodegeneration and ambiguous genitalia. We studied 12 human families with PCH7, uncovering biallelic, loss-of-function mutations in TOE1, which encodes an unconventional deadenylase. toe1-morphant zebrafish displayed midbrain and hindbrain degeneration, modeling PCH-like structural defects in vivo. Surprisingly, we found that TOE1 associated with small nuclear RNAs (snRNAs) incompletely processed spliceosomal. These pre-snRNAs contained 3' genome-encoded tails often followed by post-transcriptionally added adenosines. Human cells with reduced levels of TOE1 accumulated 3'-end-extended pre-snRNAs, and the immunoisolated TOE1 complex was sufficient for 3'-end maturation of snRNAs. Our findings identify the cause of a neurodegenerative syndrome linked to snRNA maturation and uncover a key factor involved in the processing of snRNA 3' ends.
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http://dx.doi.org/10.1038/ng.3762DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5325768PMC
March 2017

Viable phenotype of ILNEB syndrome without nephrotic impairment in siblings heterozygous for unreported integrin alpha3 mutations.

Orphanet J Rare Dis 2016 10 7;11(1):136. Epub 2016 Oct 7.

Laboratorio di Citogenetica Medica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche IRCCS-Istituto Auxologico Italiano, Via Zucchi 18, 20095, Cusano Milanino, Italy.

Background: Integrin α3 (ITGA3) gene mutations are associated with Interstitial Lung disease, Nephrotic syndrome and Epidermolysis bullosa (ILNEB syndrome). To date only six patients are reported: all carried homozygous ITGA3 mutations and presented a dramatically severe phenotype leading to death before age 2 years, from multi-organ failure due to interstitial lung disease and congenital nephrotic syndrome. The involvement of skin and cutaneous adnexa was variable with sparse hair and nail dysplasia combined or not to skin lesions ranging from skin fragility to epidermolysis bullosa-like blistering.

Results: We report on two siblings of 13 and 9 years born to non-consanguineous healthy parents, who display growth delay, severe pulmonary fibrosis with fatigue, dyspnea on exertion and wheezing, atrophic skin with erythematosus lesions, rare eyelashes/eyebrows and pachyonychia. By exome sequencing, we identified two unreported ITGA3 missense mutations, c.373G>A (p.(G125R)) in exon 3 and c.821G>A (p.(R274Q)) in exon 6, affecting highly conserved residues in the integrin α3 extracellular N-terminal β-propeller domain. Homology modelling of α3β1 heterodimer fragment, encompassing the mutation sites, showed that G125 plays a pivotal structural role in the β-propeller, while R274 might prevent the interaction between integrin and urokinase complex.

Conclusion: We report a variant of ILNEB syndrome in two siblings differing from the previously reported patients in the lack of nephrotic impairment and survival beyond childhood. Our siblings are the first reported compound heterozygous for ITGA3 mutations; this state as well as the hypomorphic nature of their p.(R274Q) mutation likely account for their survival.
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http://dx.doi.org/10.1186/s13023-016-0514-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5054609PMC
October 2016

Clinical findings in a patient with FARS2 mutations and early-infantile-encephalopathy with epilepsy.

Am J Med Genet A 2016 11 23;170(11):3004-3007. Epub 2016 Aug 23.

Paediatric Neurology Unit, Children's Hospital V. Buzzi, Milan, Italy.

The FARS2 gene encodes the mitochondrial phenylalanyl-tRNA synthetase and is implicated in autosomal recessive combined oxidative phosphorylation deficiency 14, a clinical condition characterized by infantile onset epilepsy and encephalopathy. Mutations in FARS2 have been reported in only few patients, but a detailed description of seizures, electroencephalographic patterns, magnetic resonance imaging findings, and long-term follow-up is still needed. We provide a clinical report of a child with FARS2-related disease manifesting drug-resistant infantile spasms associated with focal seizures. By comparative genomic hybridization analysis we identified a heterozygous microdeletion in the short arm of chromosome 6, inherited from the mother, that encompasses the first coding exon of FARS2. By sequencing of the FARS2 gene we identified a variant c.1156C>G; p.(R386G), inherited from the father. By using standard spectrophotometric techniques in skin fibroblasts, we found a combined abnormality of complexes I and IV of the mitochondrial respiratory chain. The main clinical features of the patient included axial hypotonia, mild distal hypertonia, and psychomotor delay. The magnetic resonance imaging showed microcephaly, frontal cerebral atrophy, and signal changes of dentate nuclei. At the age of 3 years and 6 months, the patient was still under treatment with vigabatrin and he has been seizure free for the last 23 months. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ajmg.a.37836DOI Listing
November 2016

Familial Precocious Fetal Abnormal Cortical Sulcation.

Neuropediatrics 2016 Aug 13;47(4):253-8. Epub 2016 May 13.

Department of Pediatric Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy.

The development of the human cerebral cortex is a complex and precisely programmed process by which alterations may lead to morphological and functional neurological abnormalities. We report familial cases of prenatally diagnosed abnormal brain, characterized by aberrant symmetrical mesial oversulcation of the parietooccipital lobes, in fetuses affected by abnormal skeletal features. Fetal brain anomalies were characterized by prenatal magnetic resonance imaging at 21 weeks of gestation and histologically evaluated at 22 weeks. Histological examination added relevant information showing some focal cortical areas of micropoligyria and heterotopic extension of the cortical plate into the marginal zone beneath the cortical surface. Genetic analysis of the fetuses excluded FGFR3 mutations known to be related to skeletal dysplasia and aberrant symmetrical oversulcation in other brain areas (temporal lobes). Hence, the present report suggests the existence of a class of rare syndromes of skeleton and brain development abnormality unrelated to FGFR3 mutations or related to other not described FGFR3 gene defects. Using magnetic resonance imaging, histopathology and molecular characterization we provide an example of a translational study of a rare and unreported brain congenital malformation.
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http://dx.doi.org/10.1055/s-0036-1583185DOI Listing
August 2016

Clinical, neuroradiological and molecular characterization of cerebellar dysplasia with cysts (Poretti-Boltshauser syndrome).

Eur J Hum Genet 2016 08 2;24(9):1262-7. Epub 2016 Mar 2.

CSS-Mendel Institute, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.

Cerebellar dysplasia with cysts and abnormal shape of the fourth ventricle, in the absence of significant supratentorial anomalies and of muscular involvement, defines recessively inherited Poretti-Boltshauser syndrome (PBS). Clinical features comprise non-progressive cerebellar ataxia, intellectual disability of variable degree, language impairment, ocular motor apraxia and frequent occurrence of myopia or retinopathy. Recently, loss-of-function variants in the LAMA1 gene were identified in six probands with PBS. Here we report the detailed clinical, neuroimaging and genetic characterization of 18 PBS patients from 15 unrelated families. Biallelic LAMA1 variants were identified in 14 families (93%). The only non-mutated proband presented atypical clinical and neuroimaging features, challenging the diagnosis of PBS. Sixteen distinct variants were identified, which were all novel. In particular, the frameshift variant c.[2935delA] recurred in six unrelated families on a shared haplotype, suggesting a founder effect. No LAMA1 variants could be detected in 27 probands with different cerebellar dysplasias or non-progressive cerebellar ataxia, confirming the strong correlate between LAMA1 variants and PBS.
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http://dx.doi.org/10.1038/ejhg.2016.19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4913877PMC
August 2016

Prenatal detection of 5q14.3 duplication including MEF2C and brain phenotype.

Am J Med Genet A 2016 May 10;170A(5):1352-7. Epub 2016 Feb 10.

Fetal Therapy Unit, Department of Obstetrics and Gynaecology, Children's Hospital V. Buzzi, Milan, Italy.

The 5q14.3 duplication is a rare condition comprising speech and developmental delay, microcephaly, and mild ventriculomegaly. The region 5q14.3 contains several genes but the predominant role for the onset of the neurodevelopmental phenotype has been attributed to MEF2C. We describe the prenatal identification of 5q14.3 duplication, including MEF2C, in a monochorionic twin pregnancy with corpus callosum anomalies, confirmed by autopsy. To the best of our knowledge, this cerebral finding has been observed for the first time in 5q14.3 duplication patients, possibly widening the neurological picture of this scarcely known syndrome. A pathogenetic role of MEF2C overexpression in brain development may be assumed, but further studies are needed.
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http://dx.doi.org/10.1002/ajmg.a.37594DOI Listing
May 2016

Hepatoblastoma in Rubinstein-Taybi Syndrome: A Case Report.

Pediatr Blood Cancer 2016 Mar 20;63(3):572-3. Epub 2015 Oct 20.

Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.

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http://dx.doi.org/10.1002/pbc.25806DOI Listing
March 2016

Intra-individual plasticity of the TAZ gene leading to different heritable mutations in siblings with Barth syndrome.

Eur J Hum Genet 2015 Dec 18;23(12):1708-12. Epub 2015 Mar 18.

Department of Neurosciences, Pharmacology and Child Health, University of Florence, Florence, Italy.

Infantile-onset skeletal myopathy Barth syndrome (OMIM #302060) is caused by mutations in the X-linked TAZ gene and hence usually manifests itself only in hemizygous males. Confirmatory testing is provided by mutational analysis of the TAZ gene and/or by biochemical dosage of the monolysocardiolipin/tetralinoleoyl cardiolipin ratio. Heterozygous females do not usually display a clinical phenotype but may undergo molecular genetic prenatal diagnosis during pregnancy. We characterized two novel and non-identical TAZ gene rearrangements in the offspring of a single female carrier of Barth syndrome. The hg19chrX:g.153634427_153644361delinsKP_123427.1 TAZ gene rearrangement was identified in her affected son, whereas the NM_000116.3(TAZ)c.-72_109+51del TAZ gene deletion was identified in a male foetus during a subsequent pregnancy. The unaffected mother was surprisingly found to harbour both variants in addition to a wild-type TAZ allele. A combination of breakpoint junction sequencing, linkage analysis and assessment of allelic dosage revealed that the two variants had originated independently from an apparently unstable/mutable TAZ maternal allele albeit via different mutational mechanisms. We conclude that molecular prenatal diagnosis in Barth syndrome families with probands carrying TAZ gene rearrangements should include investigation of the entire coding region of the TAZ gene. The identification of the breakpoint junctions of such gross gene rearrangements is important to ensure accurate ascertainment of carriership with a view to providing appropriate genetic counselling.
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http://dx.doi.org/10.1038/ejhg.2015.50DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4795190PMC
December 2015

Prenatal magnetic resonance imaging detection of temporal lobes and hippocampal anomalies in hypochondroplasia.

Prenat Diagn 2014 Oct 11;34(10):1015-7. Epub 2014 Jun 11.

Radiology and Neuroradiology Department, Children's Hospital V. Buzzi, Milan, Italy; Medical Genetics Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.

Hypochondroplasia (HCH) is a genetic skeletal dysplasia, inherited in an autosomal dominant fashion. About 50-70% of HCH patients have a mutation in FGFR3 gene and in the majority of cases it is a de novo mutation. Recent magnetic resonance imaging studies on relative large cohorts of HCH patients have showed a central nervous system involvement with a high incidence of characteristic temporal lobe and hippocampal abnormalities. To the best of our knowledge, this report shows the first magnetic resonance imaging prenatal detection of characteristic brain anomalies in a case of HCH, molecularly confirmed through postnatal FGFR3 analysis.
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http://dx.doi.org/10.1002/pd.4415DOI Listing
October 2014

Snyder-Robinson syndrome: a novel nonsense mutation in spermine synthase and expansion of the phenotype.

Am J Med Genet A 2013 Sep 29;161A(9):2316-20. Epub 2013 Jul 29.

Clinical Genetics Service, V. Buzzi Children's Hospital, ICP, Milan, Italy.

Snyder-Robinson syndrome is a rare form of X-linked intellectual disability caused by mutations in the spermine synthase (SMS) gene, and characterized by intellectual disability, thin habitus with diminished muscle mass, osteoporosis, kyphoscoliosis, facial dysmorphism (asymmetry, full lower lip), long great toes, and nasal or dysarthric speech. Physical signs seem to evolve from childhood to adulthood. We describe the first Italian patient with Snyder-Robinson syndrome and a novel nonsense mutation in SMS (c.200G>A; p.G67X). Apart from the typical features of the syndrome, the index patient presented with an ectopic right kidney and epilepsy from the first year of age that was characterized by focal motor seizures and negative myoclonus. The clinical and molecular evaluation of this family and the review of the literature expand the phenotype of Snyder-Robinson syndrome to include myoclonic or myoclonic-like seizures (starting even in the first years of life) and renal abnormalities in affected males.
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http://dx.doi.org/10.1002/ajmg.a.36116DOI Listing
September 2013

Neonatal suppression-burst without epileptic seizures: expanding the electroclinical phenotype of STXBP1-related, early-onset encephalopathy.

Epileptic Disord 2013 Mar;15(1):55-61

Pediatric Neurology Unit, V Buzzi Children's Hospital, ICP, Milan, Italy.

Early-onset epileptic encephalopathies (EOEEs) are characterised by epileptic seizures beginning in the first months of life, abnormal background EEG activity, and are associated with severe developmental delay and poor prognosis. Mutations and deletions in the STXBP1 gene are associated with Ohtahara syndrome, also known as "early infantile epileptic encephalopathy". We report an infant affected by EOEE with a 9q34.11 deletion that encompassed the genes STXBP1 and SPTAN1. The infant presented with neonatal encephalopathy without epileptic seizures and an EEG pattern varying from highly discontinuous to suppression-burst. This was followed by West syndrome at 2 months with atypical hypsarrhythmia and spasms, easily controlled by therapy. Our findings suggest that molecular analysis of STXBP1 should be considered for newborns affected by neonatal encephalopathy associated with a peculiar EEG pattern, even in the absence of neonatal epileptic seizures.
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http://dx.doi.org/10.1684/epd.2013.0558DOI Listing
March 2013

Genetic testing in benign familial epilepsies of the first year of life: clinical and diagnostic significance.

Epilepsia 2013 Mar 29;54(3):425-36. Epub 2013 Jan 29.

Laboratory of Neurogenetics, Department of Neuroscience, Istituto G. Gaslini, Genova, Italy.

Purpose: To dissect the genetics of benign familial epilepsies of the first year of life and to assess the extent of the genetic overlap between benign familial neonatal seizures (BFNS), benign familial neonatal-infantile seizures (BFNIS), and benign familial infantile seizures (BFIS).

Methods: Families with at least two first-degree relatives affected by focal seizures starting within the first year of life and normal development before seizure onset were included. Families were classified as BFNS when all family members experienced neonatal seizures, BFNIS when the onset of seizures in family members was between 1 and 4 months of age or showed both neonatal and infantile seizures, and BFIS when the onset of seizures was after 4 months of age in all family members. SCN2A, KCNQ2, KCNQ3, PPRT2 point mutations were analyzed by direct sequencing of amplified genomic DNA. Genomic deletions involving KCNQ2 and KCNQ3 were analyzed by multiple-dependent probe amplification method.

Key Findings: A total of 46 families including 165 affected members were collected. Eight families were classified as BFNS, 9 as BFNIS, and 29 as BFIS. Genetic analysis led to the identification of 41 mutations, 14 affecting KCNQ2, 1 affecting KCNQ3, 5 affecting SCN2A, and 21 affecting PRRT2. The detection rate of mutations in the entire cohort was 89%. In BFNS, mutations specifically involve KCNQ2. In BFNIS two genes are involved (KCNQ2, six families; SCN2A, two families). BFIS families are the most genetically heterogeneous, with all four genes involved, although about 70% of them carry a PRRT2 mutation.

Significance: Our data highlight the important role of KCNQ2 in the entire spectrum of disorders, although progressively decreasing as the age of onset advances. The occurrence of afebrile seizures during follow-up is associated with KCNQ2 mutations and may represent a predictive factor. In addition, we showed that KCNQ3 mutations might be also involved in families with infantile seizures. Taken together our data indicate an important role of K-channel genes beyond the typical neonatal epilepsies. The identification of a novel SCN2A mutation in a family with infantile seizures with onset between 6 and 8 months provides further confirmation that this gene is not specifically associated with BFNIS and is also involved in families with a delayed age of onset. Our data indicate that PRRT2 mutations are clustered in families with BFIS. Paroxysmal kinesigenic dyskinesia emerges as a distinctive feature of PRRT2 families, although uncommon in our series. We showed that the age of onset of seizures is significantly correlated with underlying genetics, as about 90% of the typical BFNS families are linked to KCNQ2 compared to only 3% of the BFIS families, for which PRRT2 represents the major gene.
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http://dx.doi.org/10.1111/epi.12089DOI Listing
March 2013

Focal seizures with affective symptoms are a major feature of PCDH19 gene-related epilepsy.

Epilepsia 2012 Dec 4;53(12):2111-9. Epub 2012 Sep 4.

Pediatric Neurology Unit, A. Meyer Children's Hospital-University of Florence, Florence, Italy.

Purpose: Mutations of the protocadherin19 gene (PCDH19) cause a female-related epilepsy of variable severity, with or without mental retardation and autistic features. Despite the increasing number of patients and mutations reported, the epilepsy phenotype associated with PCDH19 mutations is still unclear. We analyzed seizure semiology through ictal video-electroencephalography (EEG) recordings in a large series of patients.

Methods: We studied 35 patients with PCDH19 gene-related epilepsy and analyzed clinical history and ictal video-EEG recordings obtained in 34 of them.

Key Findings: Clusters of focal febrile and afebrile seizures had occurred in 34 patients, at a mean age of 10 months. The predominant and more consistent ictal sign was fearful screaming, occurring in 24 patients (70.5%); it was present since epilepsy onset in 12 and appeared later on, during the course in the remaining 12 patients. In infancy, fearful screaming mainly appeared within the context of seizures with prominent hypomotor semiology, whereas during follow-up it was associated with prominent early motor manifestations. In 16 patients, seizures were video-EEG recorded both at onset and during follow-up: in five patients (31%) seizure semiology remained identical, in 7 (44%) semiology varied and in four patients it was unclear whether ictal semiology changed with age. Three patients (9%) had both focal and generalized seizures, the latter consisting of absences and myoclonus. Ictal EEG during focal seizures showed a prominent involvement of the frontotemporal regions (22 patients). About 45% of patients had an alternating EEG pattern, with the ictal discharge migrating from one hemisphere to the contralateral during the same ictal event. Status epilepticus occurred in 30% of patients. Cognitive impairment occurred in 70%, ranging from mild (42%) to moderate (54%) and severe (4%); autistic features occurred in 28.5%. Direct sequencing detected 33 different heterozygous candidate mutations, 8 of which were novel. Mutations were missense substitutions (48.5%), premature termination (10 frameshift, 4 nonsense, and 2 splice-site mutations; 48.5%), and one in-frame deletion. Thirty candidate mutations (91%) were de novo. No specific genotype-phenotype correlation could be established, as missense and truncating mutations were associated with phenotypes of comparable severity.

Significance: Most patients with PCDH19 mutations exhibit a distinctive electroclinical pattern of focal seizures with affective symptoms, suggesting an epileptogenic dysfunction involving the frontotemporal limbic system. Awareness of this distinctive phenotype will likely enhance recognition of this disorder.
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http://dx.doi.org/10.1111/j.1528-1167.2012.03649.xDOI Listing
December 2012
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