Sandhoff disease in an extreme preterm baby with bilateral syndactyly.

andhoff disease (GM2 gangliosidosis) is much less common than Tay-Sachs disease. Both are autosomal recessive lysosomal storage disorders (GM gangliosidoses). But Sandhoff disease is caused by mutations of the gene encoding the beta sub-unit of hexosaminidase, on chromosome 5. In Tay-Sachs disease, the mutation is in the alpha sub-unit on chromosome 15.1 Since both hexosaminidase A and hexosaminidase B contain beta subunits, the activity of both these 2 enzymes is lacking in this disorder. So GM2 gangliosides and other structurally related glycolipids accumulate in the brain, liver, spleen, and kidney. We report a case of Sandhoff disease in an extreme pre-term baby with bilateral syndactyly. A female baby was born at 28 weeks of gestation with a birth weight of 770 gm to a gravida 3, para 2, 23-year-old Omani mother by assisted breech delivery. The Apgar score was 4 at one minute and 7 at 5 minutes. She was intubated and ventilated for 8 days for severe Respiratory Distress syndrome, received 2 doses of surfactant and was on nasal continuous positive airway pressure for 29 days. She had patent ductus arteriosus; closed with 3 doses of indomethacin and grade I intraventricular hemorrhage which resolved on subsequent ultrasound examinations. On clinical examination, she had bilateral syndactyly of 2nd and 3rd toes, but no other dysmorphic features. Chromosomal karyotyping was normal. Screening for retinopathy of prematurity was normal. She was discharged at 3 months of age (corrected post-conceptional age of 40 weeks) with a weight of 2 kg, normal growth pattern and reflexes, and breast-feeding. The earliest evidence of abnormality was noticed at corrected age of 3 months, when social smile was noticed to be absent. Repeat ophthalmic examination at this stage, showed normal disc and normal vessels, but macula showed definite pallor with some hypopigmentation at fovea suggestive of a cherry red spot. A metabolic storage disorder was Clinical Notes