Case Report of A Novel C.1341 Delt Homozygous Mutation in The HEXB Gene in A Girl with Photosensitive Seizure

Sandhoff disease is one of the rare lysosomal storage diseases with autosomal recessive inheritance. The progressive neurological decline and the appearance of a cherry red spot on the macula is typical. Diagnosis is confirmed by a decrease in total β-hexosaminidase A and B enzyme activities and by showing the mutation in the HEXB gene. A 14-month-old girl was referred to our clinic for developmental delay and the appearance of a cherry red spot on the macula. It was learned that she was the only child of parents who had first degree relatives among them, she had no head and neck control and did not recognize the mother. In the neurological examination, there was no eye contact and head-neck control. She had excessive irritation against noise and hypotonicity. Hepatosplenomegaly was not detected. In the enzyme study, Total β-Hexosaminidase A and B 29 nmol / hour / mg protein (N: 1223 ± 273 nmol / hour / mg protein) and in the HEXB gene study c.1341delT homozygote mutation was detected. The patient was diagnosed with Sandhoff disease, the family was informed about the disease and genetic counseling. Unilateral photosensitive seizure and electroencephalography revealed focal findings. In this case, the importance of diagnosis of ocular examination in patients with suspected metabolic disease; It was aimed to draw attention to the fact that Sandhoff disease may also be observed with atypical findings