Ocular abnormality associated with partial duplication of chromosome 13.

We studied a one-year-old child with multiple malformations and a tandem duplication of the distal two-thirds of 13q. The overall findings were similar to those usually found with partial duplication of chromosome 13. The ocular pathologic findings, including monocular spherophakia, were not suggestive of any known chromosomal syndrome, and their cytogenetic significance is not known. A review of 42 other cases of partial duplication 13 revealed a high (85%) incidence of ocular anomalies, most of which were comparatively minor or involved the ocular adnexa. Although ocular anomalies in this syndrome are associated with changes in different regions of chromosome 13, the major ones are usually associated with duplication of the proximal third of 13q and minor ones with the distal two-thirds of 13q.