.svg){kind=small}
SLC3A1 gene
The SLC3A1 gene produces a subunit of a protein complex in the kidneys that is responsible for reabsorbing specific amino acids back into the blood.
Normal Function
The SLC3A1 gene provides instructions for producing one part (subunit) of a protein made primarily in the kidneys. This subunit joins with another protein subunit, produced from the SLC7A9 gene, to form a transporter protein complex. During the process of urine formation in the kidneys, this protein complex absorbs particular protein building blocks (amino acids) back into the blood. In particular, the amino acids cystine, ornithine, arginine, and lysine are absorbed back into the blood through this mechanism.
Health Conditions Related to Genetic Changes
Cystinuria
More than 120 mutations in the SLC3A1 gene have been found to cause cystinuria. Many of these mutations alter a single DNA building block (nucleotide) or insert or delete a small number of nucleotides in the SLC3A1 gene. These changes lead to an abnormally functioning transporter protein complex, which causes certain amino acids to become concentrated in the urine. Cystine is the only amino acid that forms crystals and stones in the bladder or kidneys, leading to the signs and symptoms of cystinuria.
Other disorders
Some people with cystinuria have large DNA deletions that remove not only the SLC3A1 gene but one or more neighboring genes. Individuals with these large DNA deletions have the signs and symptoms of cystinuria, but they can also have other features:
- Hypotonia-cystinuria syndrome: Caused by deletions of the SLC3A1 and PREPL genes. Features include low muscle tone (hypotonia), poor feeding, droopy eyelids (ptosis), an elongated head (dolichocephaly), mild intellectual disability, and short stature.
- Atypical hypotonia-cystinuria syndrome: Caused by deletions of the SLC3A1, PREPL, and C2orf34 genes. Individuals have the symptoms of hypotonia-cystinuria syndrome plus mild to moderate psychomotor delay.
- 2p21 deletion syndrome: Caused by deletions of the SLC3A1, PREPL, C2orf34, and PPM1B genes. Individuals exhibit symptoms of the previous syndromes plus seizures soon after birth, moderate to severe psychomotor delay, impairments in oxidative phosphorylation, and characteristic facial features.
Other Names for This Gene
- amino acid transporter 1
- ATR1
- CSNU1
- D2H
- NBAT
- RBAT
- SLC31_HUMAN
- solute carrier family 3 (amino acid transporter heavy chain), member 1
- solute carrier family 3 (cystine, dibasic and neutral amino acid transporters), member 1
- solute carrier family 3 (cystine, dibasic and neutral amino acid transporters, activator of cystine, dibasic and neutral amino acid transport), member 1
- solute carrier family 3, member 1
Genomic Location
The SLC3A1 gene is found on chromosome 2.