Hypotonia, congenital nystagmus, and abnormal auditory brainstem response

A Taiwanese boy, 1 year, 8 months of age, is reported with poor weight gain, hypotonia, trunk ataxia, motor developmental retardation, and horizontal pendular nystagmus with only wave I on auditory brainstem responses. Our patient clinically resembled 9 patients reported in the Japanese literature. Because of its male predominance, occurrence in siblings, early onset, nonprogressive course, and characteristic auditory brainstem response findings, the syndrome may be of genetic origin and attributable to a dysgenetic brainstem lesion.