Skip to main content

Cataract 4 (CTRCT4)

Cataract 4 (CTRCT4)

OMIM number: 115700

Comments closing date: 24/01/2019

Congenital cataracts type 4 is a genetic condition caused by gene changes within the CRYGD gene on chromosome 2q33. It is inherited in an autosomal dominant manner and therefore an affected individual has a 50% chance of having a child also affected with this condition in each pregnancy. Gene changes in the CRYGD gene cause cataracts though the severity of these will vary even within the same family.

The normal function of the gene is to maintain the transparency and refractive index (the measure of the light passing through the lens) of the lens. Gene changes within the CRYGD gene can cause total cataracts as well as strabismus (misaligned eyes) and nystagmus (involuntary eye movement) from birth. Congenital cataracts are a major cause of bilateral visual impairment in childhood. Prevalence is 1-6 / 10,000 live births. Dependent on the severity at birth will depend on the age of having surgery. Individuals with congenital cataracts are at an increased risk of developing glaucoma following surgery to remove cataracts. This risk can range from 15-50% depending on the severity of cataracts and the subsequent age at time of surgery (Vishwanath et al. 2004).

A subsequent diagnosis of glaucoma (increased pressure within the eye) would require lifelong medication (eye drops) to ensure this is under control, though loss of vision can occur even with treatment and individuals may be registered as severely sight impaired. Congenital cataracts may impact an individual’s quality of life and job opportunities.

Review date: 27 December 2020