SLC6A19 gene

The SLC6A19 gene (SLC6A19 stands for Solute Carrier Family 6 Member 19) is a protein-coding gene located on chromosome 5p15.33. An important paralog of this gene is SLC6A18.

The SLC6A19 gene encodes the sodium-dependent transporter B(0)AT1 for neutral amino acids, a transmembrane transporter that actively transports most neutral amino acids across the apical membrane of epithelial cells. It is involved in amino acid import across the plasma membrane as well as in other forms of neutral amino acid transport and thus plays a central role in nutrient uptake in epithelial tissues. Its expression is high in the proximal digestive tract and the gastrointestinal tract, and high protein expression has also been detected in the hepatobiliary system.

Mutations in the SLC6A19 gene can lead to Hartnup disease , an inherited disorder with symptoms such as pellagra, cerebellar ataxia, and psychosis. The expression and function of B0AT1 (SLC6A19) in intestinal cells depends on the presence of the accessory protein angiotensin-converting enzyme 2 (ACE2), which, among other things, acts as a chaperone for the membrane transport of B0AT1.

Pathogenic variants in the SLC6A19 gene have also been described in association with hyperglycinuria and iminoglycinuria. SLC6A19 has also been described in association with episodic ataxia type 2.

ACE2 is also the cellular receptor for the Severe Acute Respiratory Syndrome coronavirus ( SARS-CoV) and for SARS-CoV-2, which caused the 2019 coronavirus pandemic (COVID-19).

1. Hashmi MS et al. (2026) Gupta V. Hartnup Disease. Feb. 13, 2023. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Jan 2026–. PMID: 32644502.
2. Zheng Y et al. (2009) A novel missense mutation in the SLC6A19 gene in a Chinese family with Hartnup disorder. Int J Dermatol. Apr 2009;48(4):388–92.