Phenotypic correlations of ocular coloboma without known cause.

Ocular coloboma can occur as an autosomal dominant condition or as part of a known syndrome or chromosomal abnormality. We have designated those patients with ocular coloboma who do not fit into any of these three groups as having coloboma without known cause. We completed a retrospective review of 58 patients from our clinics with coloboma without known cause to determine the frequency of other co-existing congenital malformations and mental retardation. Mental retardation was present in 14 of the 42 patients (33%) who were more than 1 year of age. However, only 14% of the children who had no other malformations had mental retardation, whereas 57% of those with other malformations were mentally retarded. We found that the severity of the colobomatous malformation did not correlate with intellect.