Open AccessHomozygous spinocerebellar ataxia type 3 in China: a case report
Author(s) -
Yuchao Chen,
Dan Li,
Minger Wei,
Menglu Zhou,
Linan Zhang,
Jiaoyang Yu,
Mengqiu Qiu,
Yi Jin,
Xiaodong Lü
Publication year - 2021
Publication title -
journal of international medical research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 57
eISSN - 1473-2300
pISSN - 0300-0605
DOI - 10.1177/03000605211021370
Subject(s) - spinocerebellar ataxia , trinucleotide repeat expansion , ataxia , allele , medicine , machado–joseph disease , disease , genetics , phenotype , gene , heterozygote advantage , age of onset , pathology , biology , psychiatry
Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disease caused by a heterozygous CAG repeat expansion in the ataxin 3 gene ( ATXN3). However, patients with homozygous SCA3 carrying expanded CAG repeats in both alleles of ATXN3 are extremely rare. Herein, we present a case of a 50-year-old female who had homozygous SCA3 with expansion of 62/62 repeats. Segregation analysis of the patient’s family showed both a contraction pattern of CAG repeat length and stable transmission. The present case demonstrated an earlier onset and more severe clinical phenotype than that seen in heterozygous individuals, suggesting that the gene dosage enhances disease severity.