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Tay-Sachs disease

An evidence-led atlas of HEXA deficiency, GM2 accumulation, infantile-to-adult disease spectrum, enzyme and molecular diagnosis, and supportive care.

Tay-Sachs disease · HEXA disorder · GM2 gangliosidosis type I

MONDO:0010100Public QA completeSource-bound · 4

Disease at a glance

Start with the essentials, then explore the patient and research views.

Public revision · ce0b9665eb71

Disease class
Tay-Sachs disease is an inherited neurodegenerative disorder in which GM2 ganglioside accumulates in neuronal lysosomes.
Core mechanism
It results from biallelic pathogenic HEXA variants and reduced beta-hexosaminidase A activity and is autosomal recessive.
Genes or cause
Residual enzyme activity contributes to a continuum of acute infantile, subacute juvenile, and late-onset disease.
Typical features
Infantile disease follows early normal development with motor loss, exaggerated startle, and progressive weakness beginning around three to six months.
Variability
A retinal cherry-red spot, seizures, swallowing and breathing problems, and macrocephaly can emerge during progression.
Diagnosis
Juvenile disease can cause developmental plateau and regression, spasticity, and seizures; late-onset disease can cause weakness, ataxia, or psychiatric symptoms.
Management
Diagnosis is established using Hex A enzyme analysis in serum or leukocytes together with HEXA molecular testing.
Treatment and research
Enzyme testing has limitations involving pregnancy or hormones, pseudodeficiency alleles, and B1 variants, requiring appropriate specimens and molecular interpretation.
Reading evidence
There is currently no approved disease-modifying therapy; care supports breathing, nutrition, seizures, tone, and comfort.
Key caution
Diet modification, rehabilitation, assistive devices, or gastrostomy are individualized according to swallowing and aspiration risk.

For patients and families

A structured guide for understanding the disease and preparing for clinical conversations.

At a glance

Tay-Sachs disease is an inherited neurodegenerative disorder in which GM2 ganglioside accumulates in neuronal lysosomes.

Infantile disease follows early normal development with motor loss, exaggerated startle, and progressive weakness beginning around three to six months.

How the disease works

It results from biallelic pathogenic HEXA variants and reduced beta-hexosaminidase A activity and is autosomal recessive.

Residual enzyme activity contributes to a continuum of acute infantile, subacute juvenile, and late-onset disease.

Why experiences vary

A retinal cherry-red spot, seizures, swallowing and breathing problems, and macrocephaly can emerge during progression.

Diagnosis and management

Juvenile disease can cause developmental plateau and regression, spasticity, and seizures; late-onset disease can cause weakness, ataxia, or psychiatric symptoms.

Treatment status

Diagnosis is established using Hex A enzyme analysis in serum or leukocytes together with HEXA molecular testing.

Enzyme testing has limitations involving pregnancy or hormones, pseudodeficiency alleles, and B1 variants, requiring appropriate specimens and molecular interpretation.

Reading clinical trials

Carrier, prenatal, and preimplantation options are offered with genetic counseling on enzyme and molecular-test strengths and limits.

Topics for a clinical visit

Clinical discussion should cover onset form, enzyme and molecular results, swallowing, breathing and seizure safety, supportive goals, and family testing.

Medical notice

This material is for disease education and is not a personal diagnosis or treatment instruction.

Evidence and sources

A trial registry status does not establish efficacy or regulatory approval.