Persistent Hyperplastic Primary Vitreous in Non‐identical Twins

Non‐identical twin females presented because one had a spontaneous left hyphaema. When this cleared, a retrolental vascularised white mass, presumably persistent hyperplastic primary vitreous (PHPV), was seen in the left eye. This eye was very slightly smaller than the right. The parents had noticed that her twin had a left convergent squint; the diagnosis of PHPV was also made in this twin's left eye which was also smaller than the right. An older male sibling is normal. The parents are not consanguineous. A recessive gene is the likeliest explanation, but an intra‐uterine environmental factor such as infection is a definite possibility. (No other sibships with or cases of persistent hyperplastic primary vitreous with affected first degree relatives seem to have been reported.)