Presentation
The most common form of the disease typically presents in infancy, but various other forms can present in childhood, adolescence, or even adulthood. GM2 gangliosidosis is sometimes called Tay-Sachs disease or HexA deficiency. [childrenshospital.org]
Clinical symptoms of GM1 gangliosidosis type I are presented during the first month of life. [bmcmedgenet.biomedcentral.com]
Ballooned neurons are present throughout the CNS. Clinical variation is noted. [emedicine.medscape.com]
Similarly, 5 non-consanguineous Galician heterozygous B1 variant carriers were identified, with all cases presenting the R178H mutation. [scielo.br]
The mean time from the initial presenting symptoms to the diagnosis was 7.5 ± 8.3 years (range: 0.3–26.8 years). [ncbi.nlm.nih.gov]
Entire Body System
- Developmental Delay
Initial symptoms of the infantile forms include profound hypotonia and developmental delay, followed by progressive neurological decline of motor skills, development of feeding difficulties, and onset of seizures. [ncbi.nlm.nih.gov]
Liver, Gall & Pancreas
- Hepatosplenomegaly
In type II of the disease, patients usually do not present distinctive facial features, hepatosplenomegaly and cherry red spot, making the diagnosis perplexed. [bmcmedgenet.biomedcentral.com]
As the disease progresses, children with GM1 gangliosidosis type I develop an enlarged liver and spleen (hepatosplenomegaly), skeletal abnormalities, seizures, profound intellectual disability, and clouding of the clear outer covering of the eye (the [medlineplus.gov]
However, with Sandhoff's disease there is a gross pathology in the visceral organs, such as endocardial fibrosis and hepatosplenomegaly (1). [scielo.br]
Eyes
- Visual Impairment
Signs and symptoms may include: slowing of growth plateau of gross and fine motor development developmental regression poor muscle tone (hypotonia) exaggerated startle reaction seizures visual impairment hearing loss intellectual disability Treatment [childrenshospital.org]
- Visual Impairment
Signs and symptoms may include: slowing of growth plateau of gross and fine motor development developmental regression poor muscle tone (hypotonia) exaggerated startle reaction seizures visual impairment hearing loss intellectual disability Treatment [childrenshospital.org]
Musculoskeletal
- Muscular Atrophy
Translated title of the contribution Juvenile GM2 gangliosidosis with progressive spinal muscular atrophy onset Original language French Pages (from-to) 120-123 Number of pages 4 Journal Revue Neurologique Volume 153 Issue number 2 State Published - Mar [cris.tau.ac.il]
Some patients may present with symptoms suggesting spinocerebellar degeneration, Friedreich ataxia, amyotrophic lateral sclerosis, or spinal muscular atrophy. The patient's intellect may be either mildly impaired or within normal limits. [emedicine.medscape.com]
Hexosaminidase-A deficiency presenting as atypical juvenile-onset spinal muscular atrophy. Arch Neurol. 1985;42:1176–1180. [PubMed] [Google Scholar] 55. Oates CE, Bosch EP, Hart MN. [ncbi.nlm.nih.gov]
Neurologic
- Convulsions
In general the pathology is very similar for the classic forms of Sandhoff's and Tay-Sachs disease, and deficiency of the GM2 activator, with involutional neurodegenerative symptoms, associated with alterations of language, deambulation, dystonia, convulsions [scielo.br]
- Psychomotor Regression
TSD is usually diagnosed when the patient is in early adolescence, although some psychomotor regression may begin in early childhood. [emedicine.medscape.com]
Workup
Workup and physical examination Both homozygotes and heterozygotes have a reduced concentration of sphingomyelin in their RBCs. Affected individuals have deficient Hex A activity and normal levels of the Hex B isozyme. [emedicine.medscape.com]
Treatment
Research has included Gene Therapy, Molecular Chaperone, Substrate Inhibition, Stem Cells, and Bone Marrow Treatment. [ntsad.org]
Signs and symptoms may include: slowing of growth plateau of gross and fine motor development developmental regression poor muscle tone (hypotonia) exaggerated startle reaction seizures visual impairment hearing loss intellectual disability Treatment [childrenshospital.org]
No treatments are currently approved for the gangliosidoses, and development of treatments is impaired by limited understanding of the natural history of these diseases. [ncbi.nlm.nih.gov]
Medical care Enzyme replacement has not yet been successful. [13] Because no specific treatment is available for TSD, treatment is directed at the symptoms and major associated conditions. [emedicine.medscape.com]
Supportive treatment includes ensuring proper nutrition and hydration, keeping the airway open, and seizure control with anticonvulsants. Genetic counseling is recommended for affected individuals and their families. [rarediseases.org]
Prognosis
This subacute phenotype of the B1 variant could be due to the presence of a defective allele, with the mutated Hex A conserving a residual in vivo activity against the GM2 ganglioside (1,7), although the prognosis of the disease is poor, with rapid deterioration [scielo.br]
Prevention
GM2 gangliosidosis is most often caused by a mutation in the HEXA or the GM2A gene, which prevents an enzyme called beta-hexosaminidase A from properly breaking down large molecules inside the body’s cells. [childrenshospital.org]
In 1970, TSD became the prototype for genetic disease prevention. North American individuals with a family history positive for a GM2 gangliosidosis or Ashkenazi Jewish heritage agreed to be tested. [emedicine.medscape.com]
In Tay-Sachs disease, mutations in the HEXA gene result in a defective α-subunit [4], whereas in Sandhoff disease, mutations in the HEXB gene prevent normal β-subunit production [[1], [2], [3]]. [ncbi.nlm.nih.gov]