Genotype-phenotype correlation over time in Angelman syndrome: Researching 134 patients.

Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by the loss of function of maternal UBE3A. The major cause of AS is a maternal deletion in 15q11.2-q13, and the minor causes are a UBE3A mutation, uniparental disomy (UPD), and imprinting defect (ID).

A nationwide survey of Vici syndrome in Japan.

Background: Vici syndrome (VICIS) is a congenital disorder characterized by agenesis of the corpus callosum, cataracts, hypopigmentation, cardiomyopathy, combined immunodeficiency, microcephaly, and failure to thrive. This study aimed to elucidate the number of patients with VICIS, its clinical characteristics and relevant genetic information in Japan.

Methods: After developing diagnostic criteria for VICIS, we conducted a nationwide questionnaire-based survey of VICIS in Japan.

Long-term follow-up of a patient with autosomal dominant lower extremity-predominant spinal muscular atrophy-2 due to a BICD2 variant.

Introduction: Bicaudal D homolog 2 (BICD2) is a causative gene of autosomal-dominant lower extremity-predominant spinal muscular atrophy-2 (SMA-LED2). The severity of SMA-LED2 varies widely, ranging from cases in which patients are able to walk to cases in which severe joint contractures lead to respiratory failure. In this study, we report the long-term course of a case of SMA-LED2 in comparison with previous reports.

Hemorrhagic shock and encephalopathy syndrome in a patient with a de novo heterozygous variant in KIF1A.

Introduction: KIF1A, a gene that encodes a neuron-specific motor protein, plays important roles in cargo transport along neurites. Variants in KIF1A have been described in three different disorders, and neurodegeneration and spasticity with or without cerebellar atrophy or cortical visual impairment syndrome (NESCAVS) is the severest phenotype.

Case Report: A 3-year-old girl was born at term with a birth weight of 2590 g.

Peripheral nerves are involved in hypomyelinating leukodystrophy-3 caused by a homozygous AIMP1 variant.

Introduction: Aminoacyl-tRNA synthetase-interacting multifunctional protein 1 (AIMP1) is a non-catalytic component of the multi-tRNA synthetase complex that catalyzes the ligation of amino acids to their correct tRNAs. Bi-allelic truncating variants in the AIMP1 gene have been associated with hypomyelinating leukodystrophy-3 (HLD3; MIM 260600), which is characterized by hypomyelination, microcephaly, seizures and decreased life expectancy. Although peripheral nerve involvement has been assumed for HLD3, no compelling evidence is available to date.

Two mouse models carrying truncating mutations in Magel2 show distinct phenotypes.

Schaaf-Yang syndrome (SYS) is a neurodevelopmental disorder caused by truncating variants in the paternal allele of MAGEL2, located in the Prader-Willi critical region, 15q11-q13. Although the phenotypes of SYS overlap those of Prader-Willi syndrome (PWS), including neonatal hypotonia, feeding problems, and developmental delay/intellectual disability, SYS patients show autism spectrum disorder and joint contractures, which are atypical phenotypes for PWS. Therefore, we hypothesized that the truncated Magel2 protein could potentially produce gain-of-function toxic effects.

Schaaf-Yang syndrome shows a Prader-Willi syndrome-like phenotype during infancy.

Background: Schaaf-Yang syndrome (SYS) is a newly recognized imprinting related syndrome, which is caused by a truncating variant in maternally imprinted MAGEL2 located in 15q11-q13. Yet, precise pathomechanism remains to be solved. We sequenced MAGEL2 in patients suspected Prader-Willi syndrome (PWS) to delineate clinical presentation of SYS.

A novel splice site variant in a young male exhibiting less pronounced features.

Patients with variants in exhibit syndromic intellectual disability (MIM #300354). A seven-year-old boy presented with intellectual disability, a history of seizure, characteristic facial features, and short stature. Whole-exome sequencing detected a c.

De novo variants in cause intellectual disability, autism spectrum disorder, and epilepsy with myoclonic absences.

Epilepsy with myoclonic absences is a specific seizure type characterized by bilateral rhythmic clonic jerks with impairment of consciousness. Here, we report an individual with epilepsy with myoclonic absences, mild intellectual disabilities, language disorder, and autism spectrum disorder. His interictal electroencephalogram revealed a spike-and-slow wave complex dominant in the frontal area.

Author Correction: A missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria, and cleft palate.

Since the publication of this article, it has been brought to our attention, that the identified mutation (NM_015277: c.2617 G > A; p.Glu873Lys) is identical with the mutation (NM_001144967: c.

A novel splicing mutation in in a boy with Christianson syndrome.

A loss of function mutation in (Xq26.3) is responsible for Christianson syndrome in males. We identified a novel splicing mutation (NM_006359.

Distinctive facies, macrocephaly, and developmental delay are signs of a PTEN mutation in childhood.

Background: Germline mutations of the PTEN gene are responsible for several PTEN hamartoma tumor syndromes. They are also implicated as a cause of macrocephaly and mild to severe developmental delay, regardless of the presence or absence of hamartomas in childhood. Nevertheless, because of limited information, the clinical features present during childhood in patients with a PTEN mutation are yet to be elucidated.

A novel truncating mutation in FLNA causes periventricular nodular heterotopia, Ehlers-Danlos-like collagenopathy and macrothrombocytopenia.

Introduction: Filamin A (FLNA) is located in Xq28, and encodes the actin binding protein, filamin A. A mutation in FLNA is the most common cause of periventricular nodular heterotopia (PVNH), but a clear phenotype-genotype correlation has not been established. Indeed, some patients with a FLNA mutation have recently been shown to additionally have Ehlers-Danlos-like collagenopathy or macrothrombocytopenia.

A de novo p.Arg756Cys mutation in ATP1A3 causes a distinct phenotype with prolonged weakness and encephalopathy triggered by fever.

Patients with a mutation at Arg756 in ATP1A3 have been known to exhibit a distinct phenotype, characterized by prolonged weakness and encephalopathy, triggered by febrile illness. With only eight reports published to date, more evidence is required to correlate clinical features with a mutation at Arg756. Here we report an additional case with an Arg756Cys mutation in ATP1A3.

deletion syndrome: clinical features and epigenetic delineation.

Background: Heterozygous mutations in have been reported in patients with distinct clinical features including intellectual disability. However, the precise pathomechanism underlying the phenotype remains to be uncovered, partly because of the diverse function of CTCF. Here we describe extensive clinical and genetic investigation for two patients with a microdeletion encompassing .

A novel missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria and cleft palate.

We identified a novel de novo heterozygous missense mutation in the NEDD4L gene (NM_015277: c.2617G>A; p.Glu873Lys) through whole-exome sequencing in a 3-year-old girl showing severe global developmental delay, infantile spasms, cleft palate, periventricular nodular heterotopia and polymicrogyria.