Publications by authors named "Marzia Pollazzon"

22 Publications

  • Page 1 of 1

Adducted Thumb and Peripheral Polyneuropathy: Diagnostic Supports in Suspecting White-Sutton Syndrome: Case Report and Review of the Literature.

Genes (Basel) 2021 Jun 22;12(7). Epub 2021 Jun 22.

Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy.

One of the recently described syndromes emerging from the massive study of cohorts of undiagnosed patients with autism spectrum disorders (ASD) and syndromic intellectual disability (ID) is White-Sutton syndrome (WHSUS) (MIM #616364), caused by variants in the gene (MIM *614787), located on the long arm of chromosome 1 (1q21.3). So far, more than 50 individuals have been reported worldwide, although phenotypic features and natural history have not been exhaustively characterized yet. The phenotypic spectrum of the WHSUS is broad and includes moderate to severe ID, microcephaly, variable cerebral malformations, short stature, brachydactyly, visual abnormalities, sensorineural hearing loss, hypotonia, sleep difficulties, autistic features, self-injurious behaviour, feeding difficulties, gastroesophageal reflux, and other less frequent features. Here, we report the case of a girl with microcephaly, brain malformations, developmental delay (DD), peripheral polyneuropathy, and adducted thumb-a remarkable clinical feature in the first years of life-and heterozygous for a previously unreported, de novo splicing variant in . This report contributes to strengthen and expand the knowledge of the clinical spectrum of WHSUS, pointing out the importance of less frequent clinical signs as diagnostic handles in suspecting this condition.
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http://dx.doi.org/10.3390/genes12070950DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8303405PMC
June 2021

Expanding the phenotype of Wiedemann-Steiner syndrome: Craniovertebral junction anomalies.

Am J Med Genet A 2020 12 11;182(12):2877-2886. Epub 2020 Oct 11.

Medical Genetics Unit, Meyer Children's University Hospital, Florence, Italy.

Wiedemann-Steiner syndrome (WDSTS) is a rare autosomal dominant condition caused by heterozygous loss of function variants in the KMT2A (MLL) gene, encoding a lysine N-methyltransferase that mediates a histone methylation pattern specific for epigenetic transcriptional activation. WDSTS is characterized by a distinctive facial phenotype, hypertrichosis, short stature, developmental delay, intellectual disability, congenital malformations, and skeletal anomalies. Recently, a few patients have been reported having abnormal skeletal development of the cervical spine. Here we describe 11 such individuals, all with KMT2A de novo loss-of-function variants: 10 showed craniovertebral junction anomalies, while an 11th patient had a cervical abnormality in C7. By evaluating clinical and diagnostic imaging data we characterized these anomalies, which consist primarily of fused cervical vertebrae, C1 and C2 abnormalities, small foramen magnum and Chiari malformation type I. Craniovertebral anomalies in WDSTS patients have been largely disregarded so far, but the increasing number of reports suggests that they may be an intrinsic feature of this syndrome. Specific investigation strategies should be considered for early identification and prevention of craniovertebral junction complications in WDSTS patients.
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http://dx.doi.org/10.1002/ajmg.a.61859DOI Listing
December 2020

Improving the phenotype description of Basel-Vanagaite-Smirin-Yosef syndrome, MED25-related: polymicrogyria as a distinctive neuroradiological finding.

Neurogenetics 2021 03 20;22(1):19-25. Epub 2020 Aug 20.

Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy.

Basel-Vanagaite-Smirin-Yosef syndrome (BVSYS) is an extremely rare autosomal recessive genetic disorder caused by variants in the MED25 gene. It is characterized by severe developmental delay and variable craniofacial, neurological, ocular, and cardiac anomalies. Since 2015, through whole exome sequencing, 20 patients have been described with common clinical features and biallelic variants in MED25, leading to a better definition of the phenotype associated with BVSYS. We report two young sisters, born to consanguineous parents, presenting with intellectual disability, neurological findings, and dysmorphic features typical of BVSYS, and also with bilateral perisylvian polymicrogyria. The younger sister died at the age of 1 year without autoptic examination. Whole exome sequencing detected a homozygous frameshift variant in the MED25 gene: NM_030973.3:c.1778_1779delAG, p.(Gln593Argfs). This report further delineates the most common clinical features of BVSYS and points to polymicrogyria as a distinctive neuroradiological feature of this syndrome.
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http://dx.doi.org/10.1007/s10048-020-00625-2DOI Listing
March 2021

Alazami syndrome: the first case of papillary thyroid carcinoma.

J Hum Genet 2020 Jan 28;65(2):133-141. Epub 2019 Oct 28.

Medical Genetics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy.

Alazami syndrome (MIM#615071) is a rare developmental disorder caused by biallelic variants in the LARP7 gene. Hallmark features include short stature, global developmental delay, and distinctive facial features. To date, 23 patients from 11 families have been reported in the literature. Here we describe a 19-year-old man who, in association with the typical features of Alazami syndrome, was diagnosed at the age of 14 years with papillary thyroid carcinoma, harboring the somatic BRAF V600E mutation. Whole exome sequencing revealed two novel LARP7 variants in compound heterozygosity, whereas only common variants were detected in genes associated with familial nonmedullary thyroid cancer (MIM#188550). LARP7 acts as a tumor suppressor in breast and gastric cancer, and possibly, according to recent studies, in thyroid tumors. Since thyroid cancer is rare among children and adolescents, we hypothesize that the LARP7 variants identified in our patient are responsible for both Alazami syndrome and tumor susceptibility. We also provide an overview of the clinical findings in all Alazami syndrome patients reported to date and discuss the possible pathogenetic mechanism that may underlie this condition, including the role of LARP7 in tumor susceptibility.
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http://dx.doi.org/10.1038/s10038-019-0682-5DOI Listing
January 2020

Severe Peripheral Joint Laxity is a Distinctive Clinical Feature of Spondylodysplastic-Ehlers-Danlos Syndrome (EDS)- and Spondylodysplastic-EDS-.

Genes (Basel) 2019 10 12;10(10). Epub 2019 Oct 12.

Medical Genetics Unit, Maternal and Child Health Department, Azienda USL-IRCCS of Reggio Emilia, 42122 Reggio Emilia, Italy.

Variations in genes encoding for the enzymes responsible for synthesizing the linker region of proteoglycans may result in recessive conditions known as "linkeropathies". The two phenotypes related to mutations in genes and (encoding for galactosyltransferase I and II respectively) are similar, characterized by short stature, hypotonia, joint hypermobility, skeletal features and a suggestive face with prominent forehead, thin soft tissue and prominent eyes. The most outstanding feature of these disorders is the combination of severe connective tissue involvement, often manifesting in newborns and infants, and skeletal dysplasia that becomes apparent during childhood. Here, we intend to more accurately define some of the clinical features of and -related conditions and underline the extreme hypermobility of distal joints and the soft, doughy skin on the hands and feet as features that may be useful as the first clues for a correct diagnosis.
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http://dx.doi.org/10.3390/genes10100799DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826576PMC
October 2019

Van Maldergem syndrome and Hennekam syndrome: Further delineation of allelic phenotypes.

Am J Med Genet A 2018 05;176(5):1166-1174

Department of Pediatrics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.

Biallelic variants in FAT4 are associated with the two disorders, Van Maldergem syndrome (VMS) (n = 11) and Hennekam syndrome (HS) (n= 40). Both conditions are characterized by a typical facial gestalt and mild to moderate intellectual disability, but differ in the occurrence of neonatal hypotonia and feeding problems, hearing loss, tracheal anomalies, and osteopenia in VMS, and lymphedema in HS. VMS can be caused by autosomal recessive variants in DCHS1 as well, and HS can also be caused by autosomal recessive variants in CCBE1 and ADAMTS3. Here we report two siblings with VMS and one girl with HS, all with FAT4 variants, and provide an overview of the clinical findings in all patients reported with FAT4 variants. Our comparison of the complete phenotypes of patients with VMS and HS indicates a resemblance of several signs, but differences in several other main signs and symptoms, each of marked importance for affected individuals.
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http://dx.doi.org/10.1002/ajmg.a.38652DOI Listing
May 2018

Complex cranio-vertebral malformation: disruption sequence or iniencephaly?

Clin Dysmorphol 2018 Jul;27(3):105-108

Department of Pediatrics, University of Lausanne and Lausanne University Hospital, Lausanne, Switzerland.

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http://dx.doi.org/10.1097/MCD.0000000000000218DOI Listing
July 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

Endocrinological Abnormalities Are a Main Feature of 17p13.1 Microduplication Syndrome: A New Case and Literature Review.

Mol Syndromol 2016 Nov 14;7(6):337-343. Epub 2016 Oct 14.

Clinical Genetics Unit, Università degli Studi di Parma, Parma, Italy.

To date, 5 cases of 17p13.1 microduplications have been described in the literature. Intellectual disability was reported as the core feature, together with minor facial dysmorphisms and obesity, but a characteristic phenotype for 17p13.1 microduplication has not been delineated. Here, we describe a patient with a 1.56-Mb de novo duplication in 17p13.1, affected by mild intellectual disability, facial dysmorphisms, obesity, and diabetes. By comparing the different phenotypes of currently described cases, we delineated the main clinical features of 17p13.1 microduplication syndrome. All patients described to date had variable facial dysmorphisms; therefore, it was difficult to define a common facial gestalt. Furthermore, we stress endocrinological abnormalities as important features and the need to monitor these over time.
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http://dx.doi.org/10.1159/000450718DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5131335PMC
November 2016

Neuroimaging findings in Mowat-Wilson syndrome: a study of 54 patients.

Genet Med 2017 06 10;19(6):691-700. Epub 2016 Nov 10.

Neuroradiology Unit, Arcispedale Santa Maria Nuova-IRCCS, Reggio Emilia, Italy.

Purpose: Mowat-Wilson syndrome (MWS) is a genetic disease characterized by distinctive facial features, moderate to severe intellectual disability, and congenital malformations, including Hirschsprung disease, genital and eye anomalies, and congenital heart defects, caused by haploinsufficiency of the ZEB2 gene. To date, no characteristic pattern of brain dysmorphology in MWS has been defined.

Methods: Through brain magnetic resonance imaging (MRI) analysis, we delineated a neuroimaging phenotype in 54 MWS patients with a proven ZEB2 defect, compared it with the features identified in a thorough review of published cases, and evaluated genotype-phenotype correlations.

Results: Ninety-six percent of patients had abnormal MRI results. The most common features were anomalies of corpus callosum (79.6% of cases), hippocampal abnormalities (77.8%), enlargement of cerebral ventricles (68.5%), and white matter abnormalities (reduction of thickness 40.7%, localized signal alterations 22.2%). Other consistent findings were large basal ganglia, cortical, and cerebellar malformations. Most features were underrepresented in the literature. We also found ZEB2 variations leading to synthesis of a defective protein to be favorable for psychomotor development and some epilepsy features but also associated with corpus callosum agenesis.

Conclusion: This study delineated the spectrum of brain anomalies in MWS and provided new insights into the role of ZEB2 in neurodevelopment.Genet Med advance online publication 10 November 2016.
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http://dx.doi.org/10.1038/gim.2016.176DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5438871PMC
June 2017

Impaired protein stability and nuclear localization of NOBOX variants associated with premature ovarian insufficiency.

Hum Mol Genet 2016 12;25(23):5223-5233

Laboratory of Endocrine and Metabolic Research, IRCCS Istituto Auxologico Italiano, Milan, Italy.

Premature ovarian insufficiency (POI) is a clinical syndrome defined by a loss of ovarian activity before the age of 40. Its pathogenesis is still largely unknown, but increasing evidences support a genetic basis in most cases. Among these, heterozygous mutations in NOBOX, a homeobox gene encoding a transcription factor expressed specifically by oocyte and granulosa cells within the ovary, have been reported in ∼6% of women with sporadic POI. The pivotal role of NOBOX in early folliculogenesis is supported by findings in knock-out mice. Here, we report the genetic screening of 107 European women with idiopathic POI, recruited in various settings, and the molecular and functional characterization of the identified variants to evaluate their involvement in POI onset. Specifically, we report the identification of two novel and two recurrent heterozygous NOBOX variants in 7 out of 107 patients, with a prevalence of 6.5% (upper 95% confidence limit of 11.17%). Furthermore, immunolocalization, Western Blot and transcriptional assays conducted in either HEK293T or CHO cells revealed that all the studied variants (p.R44L, p.G91W, p.G111R, p.G152R, p.K273*, p.R449* and p.D452N) display variable degrees of functional impairment, including defects in transcriptional activity, autophagosomal degradation, nuclear localization or protein instability. Several variants conserve the ability to interact with FOXL2 in intracellular aggregates. Their inability to sustain gene expression, together with their likely aberrant effects on protein stability and degradation, make the identified NOBOX mutations a plausible cause of POI onset.
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http://dx.doi.org/10.1093/hmg/ddw342DOI Listing
December 2016

Natural history and life-threatening complications in Myhre syndrome and review of the literature.

Eur J Pediatr 2016 Oct 25;175(10):1307-15. Epub 2016 Aug 25.

Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, Rome, Italy.

Unlabelled: Myhre syndrome (OMIM 139210) is a rare developmental disorder inherited as an autosomal dominant trait and caused by a narrow spectrum of missense mutations in the SMAD4 gene. The condition features characteristic face, short stature, skeletal anomalies, muscle pseudohypertrophy, restricted joint mobility, stiff and thick skin, and variable intellectual disability. While most of the clinical features manifest during childhood, the diagnosis may be challenging during the first years of life. We report on the evolution of the clinical features of Myhre syndrome during childhood in a subject with molecularly confirmed diagnosis. The clinical records of 48 affected patients were retrospectively analysed to identify any early clinical signs characterizing this disorder and to better delineate its natural history. We also note that pericarditis and laryngotracheal involvement represent important life-threatening complications of Myhre syndrome that justify the recommendation for cardiological and ENT follow-up for these patients.

Conclusion: Short length/stature, short palpebral fissures, and brachydactyly with hyperconvex nails represent signs/features that might lead to the correct diagnosis in the first years of life and direct to the proper molecular analysis. We underline the clinical relevance of pericarditis and laryngotracheal stenosis as life-threatening complications of this disorder and the need for careful monitoring, in relation to their severity.

What Is Known: • The clinical and radiological signs of the disease in children older than 7-8 years. • Pericarditis, sometimes occurring with constrictive pericardium requiring pericardiectomy, has been reported as a recurrent feature but has not been adequately stressed in previous literature. What is New: • Short length/stature, short palpebral fissures, brachydactyly with hyperconvex nails represent clinical signs that might lead to diagnosis in the first years of life. • Review of the literature showed that pericarditis and laryngotracheal complications represent major recurrent issues in patients with Myhre syndrome.
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http://dx.doi.org/10.1007/s00431-016-2761-3DOI Listing
October 2016

RIN2 syndrome: Expanding the clinical phenotype.

Am J Med Genet A 2016 09 8;170(9):2408-15. Epub 2016 Jun 8.

Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium.

Biallelic defects in the RIN2 gene, encoding the Ras and Rab interactor 2 protein, are associated with a rare autosomal recessive connective tissue disorder, with only nine patients from four independent families reported to date. The condition was initially termed MACS syndrome (macrocephaly, alopecia, cutis laxa, and scoliosis), based on the clinical features of the first identified family; however, with the expansion of the clinical phenotype in additional families, it was subsequently coined RIN2 syndrome. Hallmark features of this condition include dysmorphic facial features with striking, progressive facial coarsening, sparse hair, normal to enlarged occipitofrontal circumference, soft redundant and/or hyperextensible skin, and scoliosis. Patients with RIN2 syndrome present phenotypic overlap with other conditions, including EDS (especially the dermatosparaxis and kyphoscoliosis subtypes). Here, we describe a 10th patient, the first patient of Caucasian origin and the oldest reported patient so far, who harbors the previously identified homozygous RIN2 mutation c.1878dupC (p. (Ile627Hisfs*7)). Besides the hallmark features, this patient also presents problems not previously associated with RIN2 syndrome, including cervical vertebral fusion, mild hearing loss, and colonic fibrosis. We provide an overview of the clinical findings in all reported patients with RIN2 mutations and summarize some of the possible pathogenic mechanisms that may underlie this condition. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ajmg.a.37789DOI Listing
September 2016

Noonan syndrome-like disorder with loose anagen hair: a second case with neuroblastoma.

Am J Med Genet A 2015 Aug 5;167A(8):1902-7. Epub 2015 Apr 5.

Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.

Noonan-like syndrome with loose anagen hair (NSLH), also known as Mazzanti syndrome, is a RASopathy characterized by craniofacial features resembling Noonan syndrome, cardiac defects, cognitive deficits and behavioral issues, reduced growth generally associated with GH deficit, darkly pigmented skin, and an unique combination of ectodermal anomalies. Virtually all cases of NSLH are caused by an invariant and functionally unique mutation in SHOC2 (c.4A>G, p.Ser2Gly). Here, we report on a child with molecularly confirmed NSLH who developed a neuroblastoma, first suspected at the age 3 months by abdominal ultrasound examination. Based on this finding, scanning of the SHOC2 coding sequence encompassing the c.4A>G change was performed on selected pediatric cohorts of malignancies documented to occur in RASopathies (i.e., neuroblastoma, brain tumors, rhabdomyosarcoma, acute lymphoblastic, and myeloid leukemia), but failed to identify a functionally relevant cancer-associated variant. While these results do not support a major role of somatic SHOC2 mutations in these pediatric cancers, this second instance of neuroblastoma in NSLAH suggests a possible predisposition to this malignancy in subjects heterozygous for the c.4A>G SHOC2 mutation.
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http://dx.doi.org/10.1002/ajmg.a.37082DOI Listing
August 2015

Creatine transporter defect diagnosed by proton NMR spectroscopy in males with intellectual disability.

Am J Med Genet A 2011 Oct 9;155A(10):2446-52. Epub 2011 Sep 9.

Medical Genetics, Department of Biotechnology, University of Siena, Italy.

Creatine deficiency syndrome due to mutations in X-linked SLC6A8 gene results in nonspecific intellectual disability (ID). Diagnosis cannot be established on clinical grounds and is often based on the assessment of brain creatine levels by magnetic resonance spectroscopy (MRS). Considering high costs of MRS and necessity of sedation, this technique cannot be used as a first level-screening test. Likewise, gene test analysis is time consuming and not easily accessible to all laboratories. In this article feasibility of urine analysis (creatine/creatinine (Cr/Crn) ratio) performed by nuclear magnetic resonance (NMR) as a first level-screening test is explored. Before running a systematic selection of cases a preliminary study for further molecular analysis is shown. NMR urine spectra (n = 1,347) of male patients with an ID without a clinically recognizable syndrome were measured. On the basis of abnormal Cr/Crn ratio, three patients with the highest values were selected for molecular analysis. A confirmatory second urine test was positive in two patients and diagnosis was further confirmed by a decreased brain creatine level and by SLC6A8 gene analysis. A de novo mutation was identified in one. Another patient inherited a novel mutation from the mother who also has a mild ID. A repeat urine test was negative in the third patient and accordingly creatine level in the brain and SLC6A8 gene analysis both gave a normal result. We conclude that Cr/Crn ratio measured by NMR for male patients represents a rapid and useful first level screening test preceding molecular analysis.
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http://dx.doi.org/10.1002/ajmg.a.34208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306553PMC
October 2011

Investigation of modifier genes within copy number variations in Rett syndrome.

J Hum Genet 2011 Jul 19;56(7):508-15. Epub 2011 May 19.

Biotechnology Department, Medical Genetics Section, University of Siena, Siena, Italy.

MECP2 mutations are responsible for two different phenotypes in females, classical Rett syndrome and the milder Zappella variant (Z-RTT). We investigated whether copy number variants (CNVs) may modulate the phenotype by comparison of array-CGH data from two discordant pairs of sisters and four additional discordant pairs of unrelated girls matched by mutation type. We also searched for potential MeCP2 targets within CNVs by chromatin immunopreceipitation microarray (ChIP-chip) analysis. We did not identify one major common gene/region, suggesting that modifiers may be complex and variable between cases. However, we detected CNVs correlating with disease severity that contain candidate modifiers. CROCC (1p36.13) is a potential MeCP2 target, in which a duplication in a Z-RTT and a deletion in a classic patient were observed. CROCC encodes a structural component of ciliary motility that is required for correct brain development. CFHR1 and CFHR3, on 1q31.3, may be involved in the regulation of complement during synapse elimination, and were found to be deleted in a Z-RTT but duplicated in two classic patients. The duplication of 10q11.22, present in two Z-RTT patients, includes GPRIN2, a regulator of neurite outgrowth and PPYR1, involved in energy homeostasis. Functional analyses are necessary to confirm candidates and to define targets for future therapies.
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http://dx.doi.org/10.1038/jhg.2011.50DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145144PMC
July 2011

Syndromic mental retardation with thrombocytopenia due to 21q22.11q22.12 deletion: Report of three patients.

Am J Med Genet A 2010 Jul;152A(7):1711-7

Medical Genetics, University of Siena, Siena, Italy.

During the last few years, an increasing number of microdeletion/microduplication syndromes have been delineated. This rapid evolution is mainly due to the availability of microarray technology as a routine diagnostic tool. Microdeletions of the 21q22.11q22.12 region encompassing the RUNX1 gene have been reported in nine patients presenting with syndromic thrombocytopenia and mental retardation. RUNX1 gene is responsible for an autosomal dominant platelet disorder with predisposition to acute myelogenous leukemia. We report on three novel patients with an overlapping "de novo" interstitial deletion involving the band 21q22 characterized by array-CGH. All our patients presented with severe developmental delay, dysmorphic features, behavioral problems, and thrombocytopenia. Comparing the clinical features of our patients with the overlapping ones already reported two potential phenotypes related to 21q22 microdeletion including RUNX1 were highlighted: thrombocytopenia with +/- mild dysmorphic features and syndromic thrombocytopenia with growth and developmental delay.
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http://dx.doi.org/10.1002/ajmg.a.33478DOI Listing
July 2010

3.2 Mb microdeletion in chromosome 7 bands q22.2-q22.3 associated with overgrowth and delayed bone age.

Eur J Med Genet 2010 May-Jun;53(3):168-70. Epub 2010 Feb 26.

Medical Genetics, University of Siena, Italy.

We report a patient with mental retardation, epilepsy, overgrowth, delayed bone age, peculiar facial features, corpus callosum hypoplasia, enlarged cisterna magna and right cerebellar hypoplasia. Array-CGH analysis revealed the presence of a de novo 3.2 Mb interstitial deletion of the long arm of chromosome 7 involving bands q22.2-q22.3. The rearrangement includes 15 genes and encompasses a genomic region that represents a site of frequent loss of heterozygosity in myeloid malignancies. Four genes are implicated in the control of cell cycle: SRPK2, MLL5, RINT1 and LHFPL3. Haploinsufficiency of these genes might therefore be associated with overgrowth and could confer susceptibility to cancers or other tumours, so that attention to this possibility would be appropriate during regular medical review. In conclusion, array-CGH analysis should be performed in patients with overgrowth where the known causes have already been excluded, because some still unclassified overgrowth syndromes may be caused by subtle genomic imbalances.
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http://dx.doi.org/10.1016/j.ejmg.2010.02.003DOI Listing
October 2010

The first Italian family with tibial muscular dystrophy caused by a novel titin mutation.

J Neurol 2010 Apr 13;257(4):575-9. Epub 2009 Nov 13.

Medical Genetics, Department Molecular Biology, University of Siena, Policlinico Le Scotte, viale Bracci 2, 53100, Siena, Italy.

Tibial muscular dystrophy (TMD) or Udd myopathy is an autosomal dominant distal myopathy with late onset, at first described in the Finnish population. We report here the first Italian cases of TTN mutated titinopathy. The proband, a 60 year-old female, had the first muscular signs at the age of 59 years, with difficulty in walking and right foot drop. Muscle imaging showed selective fatty degenerative change in the anterior compartment of leg muscles. Her 67 year-old brother, started to show muscle weakness, pain at lower limbs and hypertrophy of calf muscles at the age of 66 years. Their mother began to show foot drop and impaired walking from the age of 60 years. Other relatives are reported to be affected in a similar way. Because the phenotype appeared compatible with TMD, we analyzed the TTN gene in the DNA of the proband and we identified a heterozygous mutation 293326A>C. This mutation is also present in the brother and in the other affected individuals of the same family. The mutation predicts a His33378Pro change located next to the previously known Belgian TMD mutation. The mutation was not found in 100 Italian control DNA samples. Then, since the introduction of a proline in the last domain of titin was previously known to cause TMD in French families, we can conclude that this missense mutation is the obvious pathogenetic mutation in the affected patients. No other disease causing mutations in the TTN gene have so far been reported in the Italian population.
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http://dx.doi.org/10.1007/s00415-009-5372-3DOI Listing
April 2010

Leukoencephalopathy in 21-beta hydroxylase deficiency: report of a family.

Brain Dev 2010 May 7;32(5):421-4. Epub 2009 May 7.

Department of Neurological, Neurosurgical and Behavioural Sciences, University of Siena, Siena, Italy.

21-hydroxylase deficiency is the most common cause of congenital adrenal hyperplasia, an autosomal recessive disorder characterized by impaired synthesis of cortisol from cholesterol by the adrenal cortex. Subclinical involvement of brain white matter has been reported in subjects with congenital adrenal hyperplasia. Here we report a woman with a genetically assessed classic congenital adrenal hyperplasia and brain white matter abnormalities. Both the carrier parents also showed signs of leucoencephalopathy. Common causes of leukoencephalopathy were excluded by appropriate analyses. Our observation suggests that white matter anomalies may also be present in carriers of a mutation in the CYP21 gene. We therefore suggest performing CYP21 gene analysis in subjects with brain MRI evidence of white matter abnormalities that cannot otherwise be explained.
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http://dx.doi.org/10.1016/j.braindev.2009.04.004DOI Listing
May 2010

Private inherited microdeletion/microduplications: implications in clinical practice.

Eur J Med Genet 2008 Sep-Oct;51(5):409-16. Epub 2008 Jul 9.

Medical Genetics, Molecular Biology Department, University of Siena, Viale Bracci 2, 53100 Siena, Italy.

The introduction of array-CGH analysis is allowing the identification of novel genomic disorders. However, this new high-resolution technique is also opening novel diagnostic challenges when inherited private CNVs of unclear clinical significance are found. Oligo array-CGH analysis of 84 patients with mild to severe mental retardation associated with multiple congenital anomalies revealed 10 private CNVs inherited from a healthy parent. Three were deletions (7q31, 14q21.1, Xq25) and seven duplications (12p11.22, 12q21.31, 13q31.1, 17q12, Xp22.31, Xq28) ranging between 0.1 and 3.8Mb. Six rearrangements were not polymorphic. Four overlapped polymorphic regions to the extent of 10-61%. In one case the size was different between the proband and the healthy relative. Three small rearrangements were gene deserts. The remaining seven had a mean gene content of five (ranging from 1 to 18). None of the rearranged genes is known to be imprinted. Three disease-genes were found in three different cases: KAL1 in dupXp22.31, STS in another dupXp22.31 and TCF2 in dup17q12. The patient carrying the last duplication presents sex reversal, Peters' anomaly and renal cysts and the duplication is located 4Mb away from the HSD17B1 gene, coding a key enzyme of testosterone biosynthesis. Considering the overlap with polymorphic regions, size-identity within the family, gene content, kind of rearrangement and size of rearrangement we suggest that at least in five cases the relationship to the phenotype has not to be excluded. We recommend to maintain caution when asserting that chromosomal abnormalities inherited from a healthy parent are benign. A more complex mechanism may in fact be involved, such as a concurrent variation in the other allele or in another chromosome that influences the phenotype.
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http://dx.doi.org/10.1016/j.ejmg.2008.06.003DOI Listing
November 2008

FOXG1 is responsible for the congenital variant of Rett syndrome.

Am J Hum Genet 2008 Jul 19;83(1):89-93. Epub 2008 Jun 19.

Medical Genetics, Molecular Biology Department, University of Siena, 53100 Siena, Italy.

Rett syndrome is a severe neurodevelopmental disease caused by mutations in the X-linked gene encoding for the methyl-CpG-binding protein MeCP2. Here, we report the identification of FOXG1-truncating mutations in two patients affected by the congenital variant of Rett syndrome. FOXG1 encodes a brain-specific transcriptional repressor that is essential for early development of the telencephalon. Molecular analysis revealed that Foxg1 might also share common molecular mechanisms with MeCP2 during neuronal development, exhibiting partially overlapping expression domain in postnatal cortex and neuronal subnuclear localization.
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http://dx.doi.org/10.1016/j.ajhg.2008.05.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2443837PMC
July 2008
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