NAGA gene

The NAGA gene (NAGA stands for: alpha-N-acetylgalactosaminidase) is a protein-coding gene located on chromosome 22q13.2. The NAGA gene codes for the lysosomal enzyme alpha-N-acetylgalactosaminidase, which cleaves alpha-N-acetylgalactosaminyl moieties from glycolysed conjugates.

Mutations in NAGA have been identified as the cause of Schindler disease types I and II (type II is also known as Kanzaki disease). Schindler's disease is a rare, autosomal recessive lysosomal storage disorder caused by a deficiency in alpha-N-acetylgalactosaminidase (α-NAGA) activity due to defects in the NAGA gene.

The first patient with this autosomal recessive disorder, a 46-year-old Japanese woman, showed diffuse angiokeratoma, mild intellectual impairment and peripheral neuroaxonal degeneration. Transient expression of an alpha-GalNAc construct containing the R329W mutation resulted in the expression of an immunoreactive polypeptide that has no detectable alpha-GalNAc activity. Its accumulation leads to clinically heterogeneous symptoms ranging from asymptomatic individuals to individuals with severe neurological manifestations (syn. Kanzaki disease/Wang AM et al. 1994).

1. Kanzaki T. (1995) Schindler disease/Kanzaki disease. Nihon Rinsho 53:2982-2987
2. Mohamed FE et al. (2020) A Novel Homozygous Missense Variant in the NAGA Gene with Extreme Intrafamilial Phenotypic Heterogeneity. J Mol Neurosci 70:45-55.
3. Wang AM et al. (1994) The molecular lesion in the alpha-N-acetylgalactosaminidase gene that causes angiokeratoma corporis diffusum with glycopeptiduria. J Clin Invest 94:839-845.