Meyahealth
Home
ENES
HomeGeneticsGeneNAGA gene
Back to Gene

NAGA gene

Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

NAGA gene

The NAGA gene provides instructions for making an enzyme that breaks down complex sugar-protein and sugar-fat molecules within cellular compartments called lysosomes.

Normal Function

The NAGA gene provides instructions for making an enzyme called alpha-N-acetylgalactosaminidase. This enzyme works in the lysosomes, which are compartments within cells that digest and recycle materials. The enzyme helps break down complexes called glycoproteins and glycolipids, which consist of sugar molecules attached to certain proteins and fats. Specifically, alpha-N-acetylgalactosaminidase helps remove a molecule called alpha-N-acetylgalactosamine from sugars in these complexes.

Health Conditions Related to Genetic Changes

Alpha-N-acetylgalactosaminidase deficiency

Variants (also called mutations) in the NAGA gene on chromosome 22 have been identified in people with alpha-N-acetylgalactosaminidase deficiency. This condition, which affects the nervous system, is sometimes called Schindler disease. There are three types of this deficiency, which differ in the severity of their signs and symptoms and the age at which they first appear.

Most of these variants result in the substitution of one protein building block (amino acid) for another, which is believed to alter the shape of the alpha-N-acetylgalactosaminidase enzyme. This change can interfere with the enzyme's ability to break down glycoproteins and glycolipids. As these substances accumulate in the lysosomes, they may cause cells to malfunction and eventually die. Cell damage in various tissues and organs leads to neurological problems and other signs and symptoms of this disorder.

Other Names for This Gene

  • alpha-galactosidase B
  • alpha-N-acetylgalactosaminidase precursor
  • D22S674
  • GALB
  • N-acetyl-alpha-D-galactosaminidase

Frequently Asked Questions

Type I (late‑onset) presents in adolescence or adulthood with mild motor delay and progressive muscle weakness. Type II (intermediate) shows early childhood onset, moderate neurodevelopmental delay, and possible hearing loss. Type III (classic) is severe, with infantile onset, profound neurodegeneration, and early death. Recognizing the type guides monitoring and supportive care.
The diagnosis starts with a clinical suspicion, followed by measuring enzyme activity in leukocytes or cultured fibroblasts. Genetic confirmation is obtained by sequencing the NAGA gene to identify pathogenic variants. Early testing is crucial for timely intervention and family planning.
Currently, treatment is mainly supportive: physical therapy, speech therapy, and management of seizures or hearing loss. Experimental approaches such as enzyme replacement therapy or gene therapy are under investigation but are not yet approved. Patients should be monitored regularly for neurological decline and organ involvement.
Since alpha‑N‑acetylgalactosaminidase deficiency follows an autosomal recessive inheritance, both parents must carry a pathogenic variant for a child to be affected. Carrier testing for relatives, prenatal diagnosis, and pre‑implantation genetic diagnosis are options. Discussing recurrence risk, potential outcomes, and available support resources is essential.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.