Striatonigral Degeneration, Infantile, Mitochondrial

A number sign (#) is used with this entry because mitochondrially inherited infantile bilateral striatal necrosis is caused by mutation in the ATP synthase-6 gene (MTATP6; 516060).

See also autosomal recessive infantile bilateral striatal necrosis (271930), which maps to chromosome 19q13.

Clinical Features

De Meirleir et al. (1995) reported a 2.5-year-old boy who presented with developmental delay. He was globally hypotonic and unable to walk without falling, and had choreoathetotic movements and extensor plantar responses. MRI showed lesions in the caudate and putamen, whereas the midbrain and brainstem were normal.

Molecular Genetics

In a boy with bilateral striatal necrosis, De Meirleir et al. (1995) identified a mutation in the MTATP6 gene (516060.0006). The patient had less than 3% normal mtDNA in fibroblasts and his unaffected mother had 15% normal mtDNA. The mtDNA of the grandmother had no trace of the mutation.

In 2 Jewish brothers with familial bilateral striatal necrosis, Thyagarajan et al. (1995) identified a mutation in the mitochondrial MTATP6 gene (516060.0005). The mutation was homoplasmic in muscle, leukocytes, and fibroblasts of the more severely affected patient; his affected brother had 98% mutant mtDNA. The mother and 2 other sibs were asymptomatic with varying degrees of heteroplasmy for the mutation.