A Case Of Congenital Cataract Following An Autosomal Dominant Pattern Of Inheritance

Congenital cataract is a challenging ophthalmological disorder that presents at birth or in early childhood and causes visual impairment in children worldwide. If not diagnosed early or left untreated, it can lead to potential blindness. Bilateral congenital cataract is genetic in majority of the cases while unilateral cataract is known to be more sporadic. Several modes of inheritance including autosomal dominant, autosomal recessive and X-linked patten have been proposed with the most common mutation being in the crystallin gene. We present to you a case of bilateral congenital cataract following an autosomal dominant mode of inheritance in a one-year-old child presenting to our outpatient clinic.  

This case has been diagnosed and reported in the paediatric ophthalmology clinic as part of the outpatient clinics of a hospital with a dedicated Ophthalmology department.

A one-year-old female child presented to our outpatient clinic with the complaint of deviation of both eyes for two months as described by the mother. No previous history of ocular surgery or trauma was noted. The birth history of the child was uneventful with the child being delivered by normal vaginal birth at term, and weighing three kgs at the time of delivery. The family history was interesting to note with the patient’s father, two paternal uncles as well as two out of three children of one of the above-mentioned uncles reported to have had congenital cataracts in infancy or early childhood. Despite likely genetic mutation, all family members remain phenotypically normal.

On examination, the child fixes and follows objects briskly, is noted to be orthophoric on Hirschberg test and has alternating exotropia on cover uncover test. On slit lamp examination, bilateral zonular/lamellar cataract is noted and indirect ophthalmoscopy reveals normal posterior pole in both eyes.

To determine the gene responsible, we sent a blood sample of one of the paternal uncles of the patient who also had congenital cataract in childhood for genetic testing and are awaiting results. We expect the results to be imminently available and will update them at the earliest. 

Congenital cataract is a visually devastating disorder which affects a large population of children worldwide. With there being a strong genetic association especially in bilateral cases, it is crucial to know the pattern of inheritance and the gene responsible for the mutation. With various treatment options underway including stem cell regeneration of the natural lens, genetic study of congenital cataract plays an important role in understanding the pathways and mechanisms responsible for the disease as well as for initiating appropriate treatment. Furthermore, detailed study of congenital hereditary cataracts can lead to a better understanding of the mechanisms of age-related cataracts, a common problem in the general population.