Two novel heterozygous variants in ATP1A3 cause movement disorders.

Variants in ATP1A3 cause neuropsychiatric disorders, especially those characterized by movement disorders. In this study, we performed whole exome sequencing for two patients with movement disorders and identified two novel heterozygous ATP1A3 variants, a missense c.2408G>A variant and an indel c.2672_2688+10delinsCAG variant. The unique indel variant occurred at the exon-intron boundary at the 3' end of exon 19, and mRNA analysis revealed that this variant caused in-frame indel alteration at the Ser891_Trp896 residue.

Genetic analysis of PRRT2 for benign infantile epilepsy, infantile convulsions with choreoathetosis syndrome, and benign convulsions with mild gastroenteritis.

PURPOSE: PRRT2 mutations were recently identified in benign familial infantile epilepsy (BFIE) and infantile convulsions with paroxysmal choreoathetosis (ICCA) but no abnormalities have so far been identified in their phenotypically similar seizure disorder of benign convulsions with mild gastroenteritis (CwG), while mutations in KCNQ2 and KCNQ3 have been recognized in benign familial neonatal epilepsy (BFNE). The aim of this study was to identify PRRT2 mutations in infantile convulsions in Asian families with BFIE and ICCA, CwG and BFNE. METHODS: We recruited 26 unrelated Japanese affected with either BFIE or non-familial benign infantile seizures and their families, including three families with ICCA. A total of 17 Japanese and Taiwanese with CwG, 50 Japanese with BFNE and 96 healthy volunteers were also recruited. Mutations of PRRT2 were sought using direct sequencing. RESULTS: Heterozygous truncation mutation (c.649dupC) was identified in 15 of 26 individuals with benign infantile epilepsy (52.1%). All three families of ICCA harbored the same mutation (100%). Another novel mutation (c.1012+2dupT) was found in the proband of a family with BFIE. However, no PRRT2 mutation was found in either CwG or BFNE. CONCLUSIONS: The results confirm that c.649dupC, a truncating mutation of PRRT2, is a hotspot mutation resulting in BFIE or ICCA regardless of the ethnic background. In contrast, PRRT2 mutations do not seem to be associated with CwG or BFNE. Screening for PRRT2 mutation might be useful in early-stage differentiation of BFIE from CwG.

Sweet's syndrome in a neonate with non-B54 types of human leukocyte antigen.

BACKGROUND: Sweet's syndrome (acute febrile neutrophilic dermatosis) is characterized by fever, polymorphonuclear leukocytosis of blood, painful plaques on the limbs, face and neck, and histologically a dense dermal infiltration with mature neutrophils. Sweet's syndrome is often a complication of hematologic malignant disease or drug-induced sensitivity reactions and has a significant susceptibility correlated with certain human leukocyte antigen (HLA). METHODS: A 5-week-old Japanese girl with Sweet's syndrome confirmed by skin biopsy was successfully treated and HLA analysis was performed. RESULTS: The patient was one of the youngest patients reported with Sweet's syndrome, suggesting the importance of the genetic background. Although the HLA types of the patient did not have B54, which was reported as a significant susceptibility correlation, structural analysis of the patient's HLAs suggested a similar possible motif for the bound peptides. CONCLUSION: Studies on the HLA bound peptides and HLA structural analysis for patients with Sweet's syndrome would be valuable for understanding the molecular mechanism of the pathogenesis.