Chief & Presenting Author: Dr.Shamika Patoria

Co Author(s): Dr. Hennaav Kaur Dhillon, Dr.Sumita Agarkar, Dr.Veena Noronha

Abstract

A 10-year-old girl presented with nystagmus and subnormal vision since birth. Best corrected distance
vision was 6/36 and 6/18 in the right and left eye. No significant birth or family history. She had right
exotropia and full ocular motility. Fundus examination showed bilateral temporal optic disc pallor
and foveal hypoplasia confirmed by optical coherence tomography. Neuroimaging showed calvarial
thickness and sclerosis. X ray of the skull, spine and pelvis showed sclerotic changes. Genetic testing
was positive for the CLCN7 gene, likely pathogenic for osteopetrosis. Clinical pediatric exam was
normal. She was managed conservatively with glasses.
Osteopetrosis 2 is caused by heterozygous mutations in the CLCN7 gene and is characterized by
segmentary osteosclerosis. The most common ocular association is optic atrophy due to optic canal
stenosis. CLCN7 gene mutations are responsible for majority of autosomal dominant
osteopetrosis cases (70 %).