GM2-Gangliosidosis (Sandhoff and Tay Sachs disease): Diagnosis and Neuroimaging Findings (An Iranian Pediatric Case Series)

Abstract

Objective: GM2-Gangliosidosis disease is a rare autosomal recessive genetic disorder that includes two disorders (Tay-Sachs and Sandhoff disease).These disorders cause a progressive deterioration of nerve cells and inherited deficiency in creating hexosaminidases A, B, and AB.

Materials & methods: Patients who were diagnosed withGM2-Gangliosidosis in the Neurology Department of Mofid Children's Hospital in Tehran, Iran from October 2009 to February 2014were included in our study. The disorder was confirmed by neurometabolic and enzyme level detection of hexosaminidases A, B, and AB in reference to Wagnester Laboratory in Germany. We assessed age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of 9 patients with Sandhoff disease and 9 with Tay Sachs disease.

Results: 83% of our patients were the offspring of consanguineous marriages. All of them had a developmental disorder as a chief complaint. 38%of patients had a history of developmental delay or regression and 22% had seizures. The patients with Sandhoff and Tay Sachs disease were followed for approximately 5 years and the follow-up showed all patients were bedridden or had expired due to refractory seizures, pneumonia aspiration, or swallowing disorders. Neuro-imaging findings included bilateral thalamic involvement, brain atrophy, and hypo myelination in near half of our patients (48%).

Conclusion: According to the results of this study, we suggest that cherry-red spots, hyperacusis, refractory seizures, and relative parents in children with developmental delay and/or regression should be considered for assessment of GM2-Gangliosidosis disease.

Keywords: Genetic disorders; Neurometabolic disorders; Sandhoff disease; Tay Sachs disease.

Fig.1

A 9 -month –boy patient of GM2-gangliosidosis with a dysmorphic face, protruding forehead, and a depressed nasal bridge

Fig. 2

Ophtalmoscopic pattern of 9- month-old boy patient with GM2- gangliosidosis characterized with cherry-red spot in retinal Exam

Fig 3

An 11-month-old female patient with GM2-gangliosidosis with bilateral thalamic involvement inT2 sequence of the brain MRI

Fig 4

A 10-month-old male patient with GM2-gangliosidosis with bilateral thalamic involvement in brain imaging