Tay-Sachs disease

Tay-Sachs disease is a hereditary neurodegenerative disorder resulting from excess storage of GM2 ganglioside within the lysosomes of cells. 

The incidence of the disease is estimated to be 1 in 3600 in Ashkenazi Jews with a carrier frequency of 1 in 30 and 1 in 360,000 in other population with a carrier frequency of 1 in 300. Tay-Sachs disease is the most frequently occurring sphingolipidoses.

In Tay-Sachs disease is a lysosomal storage disease and along with Sandhoff syndrome and hexosaminidase activator deficiency comprise the GM2 gangliosidoses.

Tay-Sachs is due to a mutation of the HEXA gene that results in reduced levels of the enzyme hexosaminidase-A (hex-A) which in turn results in the accumulation of GM2-ganglioside within the cells of the nervous system 3-7.

  • decreased eye contact
  • twitchy eyes (myoclonic jerks)
  • difficulty focusing on objects
  • excessive startling by sharp but not necessarily loud noises
  • limp and floppy muscles (hypotonia)
  • decreased alertness and playfulness
  • difficulty sitting up or rolling over
  • loss of motor skills
  • decreased hearing and eventual deafness
  • gradual loss of vision
  • an abnormal increase in head size (macrocephaly)

As a child with Tay-Sachs grows older, he or she may become blind, mentally retarded, paralyzed, and unresponsive to the environment. The child also may have seizures, difficulty swallowing, and difficulty breathing. Children with Tay-Sachs disease rarely live beyond 4 or 5 years of age 1-7.

Screening for Tay-Sachs disease is recommended for people in high-risk groups. This includes people of Ashkenazi Jewish descent and anyone with a history of the condition in their family.

  • preconception screening: where potential parents are able to check whether they carry the HEXA mutation before starting a family
  • antenatal screening: where a fetus is checked to see whether two copies of the HEXA mutation have been inherited, which would cause Tay-Sachs disease to develop

Macrocephaly and reduced attenuation of the cerebral white matter have been reported on  CT scans in patients with GM2 gangliosidosis 5.

MRI is superior to CT in delineating deep white matter demyelination. Thalami may show changes consistent with calcification, best seen on T2* weighted sequences. No abnormal contrast enhancement is described 1-5.

No specific treatment is currently available for Tay-Sachs disease. Management is therefore supportive. 

Inborn errors of metabolism
White matter disorders
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Article information

rID: 21778
Tag: cases
Synonyms or Alternate Spellings:
  • Tay-sachs disease
  • Tay sachs disorder

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