Three affected individuals from two apparently unrelated families of Lebanese heritage had a similar infantile presentation, comprising progressive encephalopathy, bull’s eye maculopathy, auditory neuropathy, diabetes insipidus, autonomic instability, cardiac defects (left ventricular non-compaction and biventricular systolic dysfunction, which evolved to hypertrophic cardiomyopathy by 7 weeks of age in the proband of family 1, and severe biventricular dysfunction in the younger sibling of family 2) and infantile death.
The fourth affected individual is of Caucasian background. He presented at 3 months of age with hypotonia, congenital nystagmus, and sensorineural hearing loss. He had slowly progressive encephalopathy, neurodevelopmental regression, congenital nystagmus with decreased vision, sensorineural hearing loss, failure to thrive and acquired microcephaly.