CTNS Gene: Cystinosin, Lysosomal Cystine Transporter
Genetic basis of cystinosis and lysosomal transport disorders
Gene Information Card
| Symbol | CTNS |
|---|---|
| Full Name | Cystinosin, Lysosomal Cystine Transporter |
| Gene Type | Protein coding |
| Chromosomal Location | 17p13.2 |
| NCBI Gene ID | 1497 ncbi.nlm.nih.gov/gene/1497 |
| Ensembl ID | ENSG00000140575 |
| UniProt ID | O60931 |
| OMIM ID | 606272 |
| HGNC ID | 2518 |
| Aliases | CTNS-LSB, MGC138386, MGC138388 |
Description
The CTNS gene encodes cystinosin, a lysosomal membrane protein that transports cystine out of lysosomes. Mutations in CTNS cause cystinosis, an autosomal recessive disorder characterized by accumulation of cystine crystals in tissues, leading to renal failure and other systemic complications.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cystinosis, nephropathic (infantile) | Loss-of-function mutations in CTNS impair cystine export from lysosomes, causing cystine accumulation and cellular damage. | OMIM 219800, ClinVar |
| Cystinosis, juvenile (intermediate) | Partial loss-of-function mutations lead to milder cystine accumulation and later onset. | OMIM 219900, ClinVar |
| Cystinosis, ocular (adult) | Milder mutations primarily affect the cornea, with minimal renal involvement. | OMIM 219750, ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 12.5 | Medium |
| Liver | 8.3 | Low |
| Brain | 6.1 | Low |
| Eye (retina) | 5.4 | Low |
| Pancreas | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.2 | High expression |
| HeLa | 10.1 | Medium expression |
| HepG2 | 7.8 | Low expression |
| ARPE-19 | 6.5 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.57_61del (p.Tyr19*) | Deletion | Common (founder in Northern Europe) | Nonsense, loss of function |
| c.18_21del (p.Thr7Phefs*7) | Deletion | Common (founder in Europe) | Frameshift, loss of function |
| c.922G>A (p.Gly308Arg) | Missense | Rare | Missense, loss of function |
| c.1015G>A (p.Gly339Arg) | Missense | Rare | Missense, loss of function |
Mutation functional classification
Loss of Function (LOF)
Most CTNS mutations cause loss of function, leading to cystine accumulation in lysosomes.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • L-cystine transmembrane transporter activity (GO:0015187) | • Lysosomal membrane (GO:0005765) |
| • Cystine transport (GO:0015811) | • Response to oxidative stress (GO:0006979) |
Pathways
• Amino acid transport across the lysosomal membrane
• Cystine metabolism
Protein Summary
Cystinosin is a 367-amino-acid lysosomal membrane protein with seven transmembrane domains. It functions as a H+-driven cystine symporter, exporting cystine from the lysosome to the cytosol. Defects in this transporter lead to cystine crystal accumulation in lysosomes, causing cystinosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CTNS Knockout HEK293 Cell Line | EDJ-KQ3072 | Human | 1497 | Details Get a Quote |
| CTNS Knockout A-549 Cell Line | EDJ-KQ22974 | Human | 1497 | Details Get a Quote |
| CTNS Knockout HCT 116 Cell Line | EDJ-KQ24352 | Human | 1497 | Details Get a Quote |
| CTNS Knockout HeLa Cell Line | EDJ-KQ24353 | Human | 1497 | Details Get a Quote |
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