Publications by authors named "Masayasu Ohta"

Background: Variants in the type IV collagen gene () cause early-onset cerebrovascular diseases. Most individuals are diagnosed postnatally, and the prenatal features of individuals with variants remain unclear.

Methods: We examined in 218 individuals with suspected /2-related brain defects.

View Article and Find Full Text PDF

Objectives: Acute encephalopathy is an acute brain dysfunction after preceding infection, consisting of multiple syndromes. Some syndromes, such as acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), are severe with poor outcome, whereas others, such as clinically mild encephalitis/encephalopathy with reversible splenial lesion (MERS), are mild with favorable outcome. Previous study reported the association of the thermolabile polymorphism in Carnitine Palmitoyltransferase 2 (CPT2) gene and severe syndromes of acute encephalopathy.

View Article and Find Full Text PDF

Although there are many known Mendelian genes linked to epileptic or developmental and epileptic encephalopathy (EE/DEE), its genetic architecture is not fully explained. Here, we address this incompleteness by analyzing exomes of 743 EE/DEE cases and 2366 controls. We observe that damaging ultra-rare variants (dURVs) unique to an individual are significantly overrepresented in EE/DEE, both in known EE/DEE genes and the other non-EE/DEE genes.

View Article and Find Full Text PDF

Objective: Vitamin B-dependent epilepsies are treatable disorders caused by variants in several genes, such as ,, and others. Recently, biallelic variants in formerly known as , were identified as a novel cause of vitamin B-dependent epilepsies. Our objective was to further delineate the phenotype of mutation.

View Article and Find Full Text PDF

Autoantibodies to signal recognition particle have been associated with juvenile and adult-onset necrotizing myopathy. However, only a few teenage patients with anti-signal recognition particle myopathy have been reported, and to date, to our knowledge, no patient younger than 10 years has been documented. We describe 2 Japanese girls with anti-signal recognition particle myopathy who developed symptoms from the ages of 5 and 9 years, respectively.

View Article and Find Full Text PDF

Purpose: Ohtahara syndrome is one of the most severe and earliest forms of epilepsy and is frequently associated with brain malformations, such as hemimegalencephaly. Recently, longer expansion of the first polyalanine tract of ARX was found to be causative for Ohtahara syndrome without brain malformation, whereas premature termination mutations of ARX were found to cause severe brain malformations, such as lissencephaly or hydranencephaly. Both are designated as ARX-related interneuronopathies.

View Article and Find Full Text PDF

Transient growth hormone deficiency (GHD) is occasionally found in prepubertal individuals, and this phenomenon has been variously interpreted. Sex steroids enhance GH secretion; however, the cut-off values of provocative GH tests are not modified according to the physiological changes. Physiological changes in sex steroid levels are thought to cause the image of transient GHD.

View Article and Find Full Text PDF

Recently, mutations in the GABA(A)-receptor gamma2 subunit (GABRG2) gene were identified in two families with generalized epilepsy with febrile seizures plus (GEFS+) and two families with childhood absence epilepsy (CAE) and febrile seizures (FS). We tested the hypothesis that genetic variations in the GABRG2 gene confer susceptibility to FS in the Japanese population. We performed a systematic search for mutations in 94 unrelated Japanese patients with FS and detected six variants (-158C>T, 315C>T, 588T>C, IVS5-55C>T, IVS7+20G>A, and IVS7-141T>A).

View Article and Find Full Text PDF

The voltage-gated sodium channel type II alpha polypeptide gene (SCN2A) R188W mutation with channel dysfunction was recently identified in a patient with febrile and afebrile seizures. A possible association between SCN2A R19K polymorphism and febrile seizures (FS) associated with afebrile seizures including generalized epilepsy with febrile seizures plus (GEFS+) was also noted. We attempted to identify the R188W mutation and confirm association of the R19K polymorphism in 93 Japanese patients with FS, 35 Japanese patients with FS associated with afebrile seizures including GEFS+, and 100 control subjects.

View Article and Find Full Text PDF