Overview
Sandhoff disease is an autosomal recessive lysosomal storage disorder characterized by the deficiency of β-hexosaminidase A and B, leading to the accumulation of GM2 ganglioside and progressive neurodegeneration affecting both gray matter nuclei and white matter myelin sheaths 12.Diagnosis
Clinical Presentation: Neuroregression, recurrent seizures, cherry-red spots on macula, macrocephaly, axial hypotonia, hyperacusis, gastroesophageal reflux 1.
Imaging: Brain MRI showing signal changes in thalami, cerebral white matter, and putamen 2.
Enzymatic Testing: Marked reduction in β-hexosaminidase B (HEXB) activity 2.
Genetic Testing: Identification of mutations in the HEXB gene, including novel mutations like c.1538 T>C (p.L513P) and c.299+5 G>A 23.
MLPA Assays: Useful for detecting copy number variations and specific mutations in HEXB, GM2A, and SMARCAL1 genes 3.Management
Multidisciplinary Therapy: Includes supportive care for symptoms such as seizures, respiratory support, and nutritional management 1.
No Specific Curative Treatment: Current management focuses on symptomatic relief and supportive care due to the progressive nature of the disease 12.Special Populations
Infants and Pediatrics: Early cardiac involvement, including ventricular septal defect and cardiomegaly, can precede neurological symptoms 12.
Comorbidities: Cardiac involvement, though rare, should be considered in differential diagnoses of metabolic cardiomyopathies 2.Key Recommendations
Genetic Testing for HEXB Mutations: Essential for confirming the diagnosis of Sandhoff disease (Evidence: Strong 23).
Comprehensive Cardiac Evaluation: Include cardiac assessment in infants with suspected Sandhoff disease due to potential early cardiac manifestations (Evidence: Moderate 12).
Multidisciplinary Supportive Care: Implement multidisciplinary approaches to manage symptoms and improve quality of life (Evidence: Expert opinion 1).References
1 Sahyouni JK, Odeh LBM, Mulla F, Junaid S, Kar SS, Al Boot Almarri NMJ. Infantile Sandhoff disease with ventricular septal defect: a case report. Journal of medical case reports 2022. link
2 Lee HF, Chi CS, Tsai CR. Early cardiac involvement in an infantile Sandhoff disease case with novel mutations. Brain & development 2017. link
3 Sobek AK, Evers C, Dekomien G. Integrated multiplex ligation dependent probe amplification (MLPA) assays for the detection of alterations in the HEXB, GM2A and SMARCAL1 genes to support the diagnosis of Morbus Sandhoff, M. Tay-Sachs variant AB and Schimke immuno-osseous dysplasia in humans. Molecular and cellular probes 2013. link