Congenital ocular fibrosis syndrome associated with the Prader-Willi syndrome.

We report an 11-year-old boy with both the congenital ocular fibrosis and the Prader-Willi syndromes. Since birth he has had bilateral blepharoptosis and fixed ocular misalignment in downward gaze. Pathological examination of the extraocular muscles showed replacement by fibrous tissue. Additionally, the child had the typical clinical features of the Prader-Willi syndrome including mental retardation, hypotonia, short stature, hypogonadism, and obesity. The Prader-Willi syndrome has been consistently associated with interstitial deletions of the long arm of chromosome 15. Although our patient appeared to have normal chromosomes, he may indeed have an undetectable deletion which may be responsible for both syndromes. We believe that the gene(s) for the congenital ocular fibrosis syndrome may be located near the gene(s) for the Prader-Willi syndrome on the long arm of chromosome 15.