RESUMO
PURPOSE: Cerebellar hypoplasia and atrophy (CBHA) in children is an extremely heterogeneous group of disorders, but few comprehensive genetic studies have been reported. Comprehensive genetic analysis of CBHA patients may help differentiating atrophy and hypoplasia and potentially improve their prognostic aspects. METHODS: Patients with CBHA in 176 families were genetically examined using exome sequencing. Patients with disease-causing variants were clinically evaluated. RESULTS: Disease-causing variants were identified in 96 of the 176 families (54.5%). After excluding 6 families, 48 patients from 42 families were categorized as having syndromic associations with CBHA, whereas the remaining 51 patients from 48 families had isolated CBHA. In 51 patients, 26 aberrant genes were identified, of which, 20 (76.9%) caused disease in 1 family each. The most prevalent genes were CACNA1A, ITPR1, and KIF1A. Of the 26 aberrant genes, 21 and 1 were functionally annotated to atrophy and hypoplasia, respectively. CBHA+S was more clinically severe than CBHA-S. Notably, ARG1 and FOLR1 variants were identified in 2 families, leading to medical treatments. CONCLUSION: A wide genetic and clinical diversity of CBHA was revealed through exome sequencing in this cohort, which highlights the importance of comprehensive genetic analyses. Furthermore, molecular-based treatment was available for 2 families.
Assuntos
Exoma , Malformações do Sistema Nervoso , Criança , Humanos , Exoma/genética , Mutação , Malformações do Sistema Nervoso/genética , Atrofia/genética , Receptor 1 de Folato/genética , CinesinasRESUMO
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is an autosomal recessive disorder characterized by macrocephaly, deterioration of motor function with ataxia, spasticity and mental decline. It has been revealed that the mutations in the gene, KIAA0027, were responsible for MLC and the gene was renamed subsequently 'MLC1'. A 41-year-old Japanese male with MLC, in whom a homozygous missense mutation, TCG to TTG at codon 93 resulting in S93L, was detected in the MLC1 gene, was described. MRI revealed marked cerebral atrophy and enlargement of the ventricular system. The subject's motor function had severely deteriorated, while his cognitive function had maintained at the level of a 2-year-old for the past 10 years. The mutation in the MLC1 gene of the patient is considered to be a common mutation responsible for MLC in Japanese patients because the same mutation had been detected in two other Japanese patients with MLC.