Publications by authors named "Maria M Mancardi"

8 Publications

  • Page 1 of 1

KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum.

Brain 2021 Jun 11. Epub 2021 Jun 11.

Pediatric Neurology Department, Lyon University Hospital, 69500 Bron, France.

Variants in KCNT1, encoding a sodium-gated potassium channel (subfamily T member 1), have been associated with a spectrum of epilepsies and neurodevelopmental disorders. These range from familial autosomal dominant or sporadic sleep-related hypermotor epilepsy ((AD)SHE) to epilepsy of infancy with migrating focal seizures (EIMFS) and include developmental and epileptic encephalopathies (DEE). This study aims to provide a comprehensive overview of the phenotypic and genotypic spectrum of KCNT1 mutation-related epileptic disorders in 248 individuals, including 66 unpreviously published and 182 published cases, the largest cohort reported so far. Four phenotypic groups emerged from our analysis: i) EIMFS (152 individuals, 33 previously unpublished); ii) DEE other than EIMFS (non-EIMFS DEE) (37 individuals, 17 unpublished); iii) (AD)SHE (53 patients, 14 unpublished); iv) other phenotypes (6 individuals, 2 unpublished). In our cohort of 66 new cases, the most common phenotypic features were: a) in EIMFS, heterogeneity of seizure types, including epileptic spasms, epilepsy improvement over time, no epilepsy-related deaths; b) in non-EIMFS DEE, possible onset with West syndrome, occurrence of atypical absences, possible evolution to DEE with SHE features; one case of sudden unexplained death in epilepsy (SUDEP); c) in (AD)SHE, we observed a high prevalence of drug-resistance, although seizure frequency improved with age in some individuals, appearance of cognitive regression after seizure onset in all patients, no reported severe psychiatric disorders, although behavioural/psychiatric comorbidities were reported in about 50% of the patients, SUDEP in one individual; d) other phenotypes in individuals with mutation of KCNT1 included temporal lobe epilepsy, and epilepsy with tonic-clonic seizures and cognitive regression. Genotypic analysis of the whole cohort of 248 individuals showed only missense mutations and one inframe deletion in KCNT1. Although the KCNT1 mutations in affected individuals were seen to be distributed among the different domains of the KCNT1 protein, genotype-phenotype considerations showed many of the (AD)SHE-associated mutations to be clustered around the RCK2 domain in the C-terminus, distal to the NADP domain. Mutations associated with EIMFS/non-EIMFS DEE did not show a particular pattern of distribution in the KCNT1 protein. Recurrent KCNT1 mutations were seen to be associated with both severe and less severe phenotypes. Our study further defines and broadens the phenotypic and genotypic spectrums of KCNT1-related epileptic conditions and emphasizes the increasingly important role of this gene in the pathogenesis of early onset DEEs as well as in focal epilepsies, namely (AD)SHE.
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June 2021

Mesial Temporal Sclerosis as Late Consequence of Posterior Reversible Encephalopathy Syndrome in Pediatric Haemato-oncological Patients.

J Pediatr Hematol Oncol 2021 Mar 3. Epub 2021 Mar 3.

Hematopoietic Stem Cell Transplantation Unit, Department of Haemato-Oncology Child Neuropsychiatry Unit Neuroradiology Unit, IRCSS Istituto Giannina Gaslini, Genoa, Italy Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa Department of Pediatrics, Pediatric Oncology and Haematology Unit "Lalla Seràgnoli" Child Neurology and Psychiatry Unit, St. Orsola-Malpighi Hospital, University of Bologna Neuroradiology Unit, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna Department of Neuroscience, University of Turin, Turin, Italy.

Objectives: Drug resistant epilepsy has rarely been reported following posterior reversible encephalopathy syndrome (PRES), with few cases of mesial temporal sclerosis (MTS). The aim of this study was to report clinical and neuroimaging features of MTS subsequent to PRES in haemato-oncological/stem cell transplanted children.

Materials And Methods: Among 70 children treated in 2 pediatric haemato-oncological Italian centers between 1994 and 2018 and presenting an episode of PRES, we retrospectively identified and analyzed a subgroup of patients who developed epilepsy and MTS.

Results: Nine of 70 patients (12.8%) developed post-PRES persistent seizures with magnetic resonance imaging evidence of MTS. One patient died few months after MTS diagnosis, because of hematological complications; the remaining 8 patients showed unprovoked seizures over time leading to the diagnosis of epilepsy, focal in all and drug resistant in 4. At PRES diagnosis, all patients with further evidence of epilepsy and MTS suffered of convulsive seizures, evolving into status epilepticus in 3. In 3 patients a borderline cognitive level or intellectual disability were diagnosed after the onset of epilepsy, and 2 had behavioral problems impacting their quality of life.

Conclusions: MTS and long-term focal epilepsy, along with potential cognitive and behavioral disorders, are not uncommon in older pediatric patients following PRES.
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March 2021

Genotype-phenotype correlations in patients with de novo pathogenic variants.

Neurol Genet 2020 Dec 30;6(6):e528. Epub 2020 Nov 30.

Department of Neurosciences (F. Malerba, G.B., E.A., A. Riva, V.S., L.N., C. Minetti, F.Z., P.S.), Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova; Pediatric Neurology and Muscular Diseases Unit (F. Malerba, G.B., F. Marchese, E.A., A. Riva, M.S.V., V.S., C. Minetti, P.S.), IRCCS Istituto G. Gaslini; Center for Synaptic Neuroscience and Technology ([email protected]) (G.A., L.M., F.B.), Istituto Italiano di Tecnologia; Department of Experimental Medicine (G.A.), Università degli Studi di Genova; Laboratory of Human Genetics (E.G.); Unit of Medical Genetics (F. Madia, F.Z.), IRCCS Istituto G. Gaslini, Genova, Italy; Child Neurology and Neurorehabilitation Unit (M.A.), Department of Pediatrics, Central Hospital of Bolzano, Bolzano; Child Neurology and Psychiatry Unit (L.G., P.A., P.M.), ASST Spedali Civili, Brescia; Neurology Unit (M. Trivisano, N.S.), Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Roma; Child Neurology Unit (A. Russo, G.G.), IRCCS, Institute of Neurological Sciences of Bologna; Child Neuropsychiatry Unit (F.R.), U.O.N.P.I.A. ASST-Rhodense, Rho, Milano; Neurology Unit and Laboratories (T.P.), A. Meyer Children's Hospital, Firenze; Child Neurology and Psychiatric Unit (C. Marini), Pediatric Hospital G. Salesi, United Hospital of Ancona; Child Neuropsychiatry Unit (M.M.M., L.N.), IRCCS Istituto G. Gaslini, Genova; Department of Pediatric Neuroscience (E.F.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Genetics of Neurodegenerative and Metabolic Diseases (B. Castellotti), Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano; Department of Child Neuropsychiatry (G.C.), Epilepsy Center, C. Poma Hospital, Mantova; Fondazione Poliambulanza Brescia (G.C.); Epilepsy Center (A.C.), Department of Neuroscience, Reproductive and Odontostomatological Sciences, Università degli Studi di Napoli Federico II, Napoli; Department of Pediatrics (A.V.), University of Perugia; Section of Pharmacology (F. Miceli, M. Taglialatela), Department of Neuroscience, Reproductive and Odontostomatological Sciences, Università degli Studi di Napoli Federico II, Napoli; IRCCS Ospedale Policlinico San Martino (L.M., F.B.), Genova, Italy; Division of Pediatric Neurology (M.R.C.), Saint-Luc University Hospital, and Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain, Brussels, Belgium; Department of Epilepsy Genetics and Personalized Treatment (K.M.J., R.S.M.), The Danish Epilepsy Center Filadelfia, Dianalund, Denmark; Institute for Regional Health Services (K.M.J., R.S.M.), University of Southern Denmark, Odense, Denmark; Department of Neurology (B. Ceulemans, S.W.), University Hospital Antwerp; Applied & Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology; Laboratory of Neurogenetics (S.W.), Institute Born-Bunge, University of Antwerp, Belgium; and Department of Life and Environmental Sciences (L.M.), Polytechnic University of Marche, Ancona, Italy.

Objective: Early identification of de novo variants in patients with epilepsy raises prognostic issues toward optimal management. We analyzed the clinical and genetic information from a cohort of patients with de novo pathogenic variants to dissect genotype-phenotype correlations.

Methods: Patients with de novo pathogenic variants were identified from Italy, Denmark, and Belgium. Atomic resolution Kv7.2 structures were also generated using homology modeling to map the variants.

Results: We included 34 patients with a mean age of 4.7 years. Median seizure onset was 2 days, mainly with focal seizures with autonomic signs. Twenty-two patients (65%) were seizure free at the mean age of 1.2 years. More than half of the patients (17/32) displayed severe/profound intellectual disability; however, 4 (13%) of them had a normal cognitive outcome.A total of 28 de novo pathogenic variants were identified, most missense (25/28), and clustered in conserved regions of the protein; 6 variants recurred, and 7 were novel. We did not identify a relationship between variant position and seizure offset or cognitive outcome in patients harboring missense variants. Besides, recurrent variants were associated with overlapping epilepsy features but also variable evolution regarding the intellectual outcome.

Conclusions: We highlight the complexity of variant interpretation to assess the impact of a class of de novo mutations. Genetic modifiers could be implicated, but the study paradigms to successfully address the impact of each single mutation need to be developed.
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December 2020

Substrate reduction therapy with Miglustat in pediatric patients with GM1 type 2 gangliosidosis delays neurological involvement: A multicenter experience.

Mol Genet Genomic Med 2020 10 11;8(10):e1371. Epub 2020 Aug 11.

Department of Biomedical Science and Human Oncology, Pediatric Unit, University of Bari "Aldo Moro", Bari, Italy.

Background: In GM1 gangliosidosis the lack of function of β-galactosidase results in an accumulation of GM1 ganglioside and related glycoconjugates in visceral organs, and particularly in the central nervous system, leading to severe disability and premature death. In the type 2 form of the disease, early intervention would be important to avoid precocious complications. To date, there are no effective therapeutic options in preventing progressive neurological deterioration. Substrate reduction therapy with Miglustat, a N-alkylated sugar that inhibits the enzyme glucosylceramide synthase, has been proposed for the treatment of several lysosomal storage disorders such as Gaucher type 1 and Niemann Pick Type C diseases. However, data on Miglustat therapy in patients with GM1 gangliosidosis are still scarce.

Methods: We report here the results of Miglustat administration in four Italian children (average age: 55 months, range 20-125) affected by GM1 gangliosidosis type 2 treated in three different Italian pediatric hospitals specialized in metabolic diseases.

Conclusion: This treatment was safe and relatively well tolerated by all patients, with stabilization and/or slowing down of the neurological progression in three subjects.
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October 2020

Novel CNS malformations and skeletal anomalies in a patient with Beaulieu-boycott-Innes syndrome.

Am J Med Genet A 2018 12 20;176(12):2835-2840. Epub 2018 Sep 20.

UOC Neurochirurgia, Istituto Giannina Gaslini, Genoa, Italy.

THO/TREX (transcription/export) is a conserved eukaryotic complex that plays a crucial role in gene expression and prevents DNA damage during mitosis and meiosis. In mammals, TREX is essential during embryogenesis, determining stem cell fate specification by regulating posttranscriptional self-renewal and differentiation in several tissues. It is composed of a core called THO, consisting of THOC1, 2, 5, 6, 7, and additional proteins. Bi-allelic mutations in THOC6 have been associated to Beaulieu-Boycott-Innes syndrome (BBIS), a syndromic form of intellectual disability (ID). To date, nine patients harbouring homozygous or compound heterozygous mutations in THOC6 have been reported. Despite the clinical heterogenity and subtle dysmorphic features in some individuals, distinctive facial features are tall forehead, short and upslanting palpebral fissures, deep set eyes, flat philtrum, and malocclusion. Nonlife threatening congenital anomalies are common, including cardiac and renal malformations, anteriorly displaced anus, cryptorchidism in males, submucous cleft palate, and corpus callosum dysgenesis. Affected patients usually have short stature, mild microcephaly, and mild to moderate ID. Here, we describe an Italian patient with BBIS, carrying two compound heterozygous loss-of-function (LoF) variants in THOC6 (c.577C > T, p.R193* and c.792_793delCA, p.V264Vfs*48). In addition to the common phenotype, she displays cerebellar hypoplasia with severe vermian dysgenesis and hydrocephalus due to aqueductal stenosis, multiple skeletal anomalies and hypergonadotropic hypogonadism. Thus, we review the previous cases and discuss the phenotypic spectrum of BBIS, providing further evidence regarding the pivotal role of TREX complex in human development.
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December 2018

TBC1D24 genotype-phenotype correlation: Epilepsies and other neurologic features.

Neurology 2016 07 8;87(1):77-85. Epub 2016 Jun 8.

Objective: To evaluate the phenotypic spectrum associated with mutations in TBC1D24.

Methods: We acquired new clinical, EEG, and neuroimaging data of 11 previously unreported and 37 published patients. TBC1D24 mutations, identified through various sequencing methods, can be found online (

Results: Forty-eight patients were included (28 men, 20 women, average age 21 years) from 30 independent families. Eighteen patients (38%) had myoclonic epilepsies. The other patients carried diagnoses of focal (25%), multifocal (2%), generalized (4%), and unclassified epilepsy (6%), and early-onset epileptic encephalopathy (25%). Most patients had drug-resistant epilepsy. We detail EEG, neuroimaging, developmental, and cognitive features, treatment responsiveness, and physical examination. In silico evaluation revealed 7 different highly conserved motifs, with the most common pathogenic mutation located in the first. Neuronal outgrowth assays showed that some TBC1D24 mutations, associated with the most severe TBC1D24-associated disorders, are not necessarily the most disruptive to this gene function.

Conclusions: TBC1D24-related epilepsy syndromes show marked phenotypic pleiotropy, with multisystem involvement and severity spectrum ranging from isolated deafness (not studied here), benign myoclonic epilepsy restricted to childhood with complete seizure control and normal intellect, to early-onset epileptic encephalopathy with severe developmental delay and early death. There is no distinct correlation with mutation type or location yet, but patterns are emerging. Given the phenotypic breadth observed, TBC1D24 mutation screening is indicated in a wide variety of epilepsies. A TBC1D24 consortium was formed to develop further research on this gene and its associated phenotypes.
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July 2016