Non-syndrome posterior lenticonus a cause of childhood catarct: Evidence for X-linked inheritance

Abstract

Purpose. When an X-linked pedigree of posterior lenticonus with cataract was identified further evidence for X-linked inheritance of this condition was sought. Methods. Forty-three cases of posterior lenticonus were identified from a database of 354 children with cataract. Two children with the X-linked syndromes of Lowe and Nance-Horan and 3 children with Fanconi syndrome have been excluded from further analysis. None of the children was deaf. None of the non-syndromic cases had microcornea. Results. There were 38 cases of non-syndromic posterior lenticonus (Ο11%). There were 15 children from 13 pedigrees and 23 apparently sporadic cases. Of the 106 cases on the database with unilateral cataract 15 had posterior lenticonus (Ο14%). Eleven of 13 pedigrees were compatible with X-linked inheritance or autosomal dominant inheritance with variable expression. However, in 2 pedigrees there was father to son transmission. Conclusions. Posterior lenticonus is a common cause of unilateral infantile cataract, but is thought to be a rare cause of bilateral cataracts. This study suggests that posterior lenticonus is responsible for a significant proportion of childhood cataracts (Ο14% of unilateral and Ο9% of bilateral cases). Posterior lenticonus is generally thought to occur as a sporadic condition. This study demonstrates that there is a family history of early-onset cataract in a significant number of bilateral cases (Ο58%).