Machado-Joseph Disease: Report of a Chinese Family

Machado-Joseph disease is an autosomal dominant multisystem motor degeneration, has been described mainly in people of Portuguese descent. It is characterized by cerebellar ataxia, pyramidal signs, and progressive external ophthalmoplegia. The pathogenic gene responsible for the disease, which was recently identified, contains an abnormal CAG expansion in the coding region (14q24.3-32.1). We report the characteristically clinical and genetic findings in two persons from a family of Chinese descents had a spinocerebellar ataxia of adult onset that extended over two generations. They developed with predominantly cerebellar ataxia with pyradmidal signs, limitation of upward gaze, nystagmus, and distal muscle atrophy. The genetic consultation revealed over expansion of CAG repeat in chromosome 14q. The length of CAG repeat was expanded to 73 and 76 in these two patients, respectively. Clinical and genetic data diagnosed they to have Machado-Joseph disease.