Tay–Sachs disease
Human medical condition / From Wikipedia, the free encyclopedia
Dear Wikiwand AI, let's keep it short by simply answering these key questions:
Can you list the top facts and stats about Tay–Sachs disease?
Summarize this article for a 10 year old
Tay–Sachs disease is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord.[1] The most common form is infantile Tay–Sachs disease, which becomes apparent around the age of three to six months of age, with the baby losing the ability to turn over, sit, or crawl.[1] This is then followed by seizures, hearing loss, and inability to move, with death usually occurring by the age of three to five.[3][1] Less commonly, the disease may occur later in childhood, adolescence, or adulthood (juvenile or late-onset).[1] These forms tend to be less severe,[1] but the juvenile form typically results in death by age 15.[4]
Tay–Sachs disease | |
---|---|
Other names | GM2 gangliosidosis, hexosaminidase A deficiency[1] |
Cherry-red spot as seen in the retina in Tay–Sachs disease. The fovea's center appears bright red because it is surrounded by a whiter than usual area. | |
Specialty | Medical genetics |
Symptoms | Initially: Decreased ability to turn over, sit, or crawl[1] Later: Seizures, hearing loss, inability to move[1] |
Usual onset | Three to six months of age[1] |
Duration | Long term[2] |
Types | Infantile, juvenile, late-onset[2] |
Causes | Genetic (autosomal recessive)[1] |
Diagnostic method | Testing blood hexosaminidase A levels, genetic testing[2] |
Differential diagnosis | Sandhoff disease, Leigh syndrome, neuronal ceroid lipofuscinoses[2] |
Treatment | Supportive care, psychosocial support[2] |
Prognosis | Death often occurs in early childhood[1] |
Frequency | Rare in the general population[1] |
Named after |
Tay–Sachs disease is caused by a genetic mutation in the HEXA gene on chromosome 15, which codes a subunit of the hexosaminidase enzyme known as hexosaminidase A.[1] It is inherited in an autosomal recessive manner.[1] The mutation disrupts the activity of the enzyme, which results in the build-up of the molecule GM2 ganglioside within cells, leading to toxicity.[1] Diagnosis may be supported by measuring the blood hexosaminidase A level or genetic testing.[2] Tay–Sachs disease is a type of GM2 gangliosidosis and sphingolipidosis.[5]
The treatment of Tay–Sachs disease is supportive in nature.[2] This may involve multiple specialities as well as psychosocial support for the family.[2] The disease is rare in the general population.[1] In Ashkenazi Jews, French Canadians of southeastern Quebec, the Old Order Amish of Pennsylvania, and the Cajuns of southern Louisiana, the condition is more common.[2][1] Approximately 1 in 3,600 Ashkenazi Jews at birth are affected.[2]
The disease is named after British ophthalmologist Waren Tay, who in 1881 first described a symptomatic red spot on the retina of the eye; and American neurologist Bernard Sachs, who described in 1887 the cellular changes and noted an increased rate of disease in Ashkenazi Jews.[6] Carriers of a single Tay–Sachs allele are typically normal.[2] It has been hypothesized that being a carrier may confer protection from tuberculosis, explaining the persistence of the allele in certain populations.[7] Researchers are looking at gene therapy or enzyme replacement therapy as possible treatments.[2]