History And Physical Examinations Pointed Toward The Diagnosis Of GM2 Gangliosidosis

Abstract

Magnetic resonance spectroscopy (MRS) trace did not reveal high creatinine or N-acetyl aspartate (NAA) peaks. No signifcant lactate level was demonstrated (Fig. 5). Metabolic workup revealed a serum fnding of traceto-absent total serum HEX A and HEX B (0.0 nmol/ min/ml; reference value > 20 nmol/min/ml) explaining the defciency of the β subunit of HEX and consequent defciency of HEX B. Te serum HEX A percentage was 100% (reference value 20–90%). Tis biochemical fndings of low total HEX and defcient HEX B activities, with high percentage of HEX A/total HEX activity suggested the diagnosis of SD. Oligosaccharide urine screen was positive in the urine sample, and genetic testing confrmed the diagnosis of SD with homozygous deletion c.(445+1_512-1)_(669+1_1170) in the HEXB gene. Te parents were advised to consent to genetic analysis, but they refused