Gene
TTC21B
tetratricopeptide repeat domain 21B
- HGNC 25660(opens in a new tab)
- Ensembl gene ENSG00000123607(opens in a new tab)
- NCBI Gene 79809(opens in a new tab)
Summary
- Cytogenetic location
- 2q24.3
- Coordinates
- Chromosome 2: 165,873,362–165,953,776 (GRCh38)
- Exons
- 29 exons across 80.4 kb
- Protein
- 1,316 amino acids
- Inheritance
- Autosomal recessive
- Also known as
- FLJ11457, JBTS11, NPHP12, IFT139B, THM1, FAP60, FLA17, IFT139, CFAP60
- MANE Select transcript
- ENST00000243344.8NM_024753.5
- Locus type
- gene with protein product
- Very high
- Confident
- Low
- Very low
Reference genomeGRCh38hg38
Positions on gene and variant pages follow this choice, in this browser.
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Get my Genome TestCurated report relevant to this gene
Nephronophthisis and Senior-Løken Syndrome
- NephronophthisisAutosomal recessive
A recessively inherited kidney disease, caused by variants in NPHP1 and other cilia genes, in which progressive tubulointerstitial scarring leads to kidney failure, typically in the first three decades of life.
- ClinGen rates the link definitive
- 3 GenCC submitters rate it definitive or strong
What knowing changes
Knowing allows regular kidney function monitoring, timely planning for dialysis or transplantation, and carrier testing for relatives.
Inheritance
- Autosomal recessive
- It takes a changed copy from each parent. With one, you are a carrier and usually unaffected; when both parents are carriers, each child has a one-in-four chance of inheriting two.
How TTC21B is laid out
- Coding sequence
- Untranslated region
- Intron
- Direction of transcription
- Known disease-causing sites
- Stretches short reads find hard
Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.
Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).
Nearby genes from Ensembl release 116, on GRCh38.
Exons make up 5.4 kb of the gene's 80.4 kb; 3,951 of those bases code for the protein.
How a genome test reads TTC21B
122
positions in TTC21B where ClinVar classes a change as pathogenic or likely pathogenic
None of them falls in a region short reads find hard.
A whole genome covers all 80.4 kb of TTC21B, introns included, not only the 5.4 kb of exons.
Traits linked to TTC21B
The Human Phenotype Ontology lists these as features of the rare conditions TTC21B can cause. Each trait's page lists the other genes linked to it.
Abnormality of the musculoskeletal system
- Narrow chest
- Short long bone
- Abnormal shape of pelvic girdle bone
- Abnormal skeletal development
- Abnormality of the ribs
- Shorter than typical length between neck and abdomen
- Abnormal collarbone
- Abnormality of the sternum
Show 2 more traits
External links
Gene records
Transcript
Protein
Where this comes from
- HGNC: the gene's symbol, name, other symbols and location.
- MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
- GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
- The ACMG secondary findings list, SF v3.2.
- ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
- The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
- Data release 2026.10.16-c6eea6bf.
Cite this page
Dante Labs. (n.d.). TTC21B gene: tetratricopeptide repeat domain 21B. Retrieved 17 October 2026, from https://dantelabs.com/genes/ttc21b
Dante Labs. TTC21B gene: tetratricopeptide repeat domain 21B [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/ttc21b
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