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Gene

TTC8

tetratricopeptide repeat domain 8

Summary

Cytogenetic location
14q31.3
Coordinates
Chromosome 14: 88,824,651–88,877,988 (GRCh38)
Exons
15 exons across 53.3 kb
Protein
515 amino acids
Inheritance
Autosomal recessive
Also known as
BBS8, RP51
MANE Select transcript
ENST00000380656.7NM_144596.4
Locus type
gene with protein product
  • Very high
  • Confident
  • Low
  • Very low

Reference genomeGRCh38

Positions on gene and variant pages follow this choice, in this browser.

Curated reports relevant to this gene

  • Bardet-Biedl and Alström Syndromes

    • Bardet-Biedl syndromeAutosomal recessive

      A recessive ciliopathy caused by variants in more than 20 genes (most often BBS1 and BBS10) that causes retinal dystrophy, obesity, extra fingers or toes, kidney anomalies and learning difficulties.

      • 4 GenCC submitters rate it definitive or strong
      What knowing changes

      Diagnosis allows eye, kidney and diabetes surveillance, and setmelanotide is an approved treatment for obesity in Bardet-Biedl syndrome.

Broader groupings

  • Retinitis Pigmentosa

    • One of 77 genes linked to it

      A group of inherited retinal dystrophies with progressive loss of rod and then cone photoreceptors, causing night blindness and gradual loss of peripheral vision.

      • 2 GenCC submitters rate it definitive or strong

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 TTC8 is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 14, with a bracket where TTC8 sits. TTC8 and 5 genes near it on chromosome 14, from 88,351,320 to 89,351,319.Chromosome 1414q31.3p13p12p11.2p11.1q11.1q11.2q12q13.1q13.2q13.3q21.1q21.2q21.3q22.1q22.2q22.3q23.1q23.2q23.3q24.1q24.2q24.3q31.1q31.2q31.3q32.11q32.12q32.13q32.2q32.31q32.32q32.3388.4 Mb88.6 Mb88.8 Mb89 Mb89.2 MbSPATA7: 88,384,924–88,472,529, forward strandSPATA7PTPN21: 88,465,778–88,555,019, reverse strandPTPN21ZC3H14: 88,562,948–88,627,596, forward strandZC3H14EML5: 88,612,240–88,792,994, reverse strandEML5TTC8: 88,824,651–88,877,988, forward strandTTC8FOXN3: 89,124,871–89,619,496, reverse strandFOXN3Diagram of TTC8: 15 exons on the forward strand of chromosome 14Exon 1: 5 known disease-causing sitesExon 3: 6 known disease-causing sitesExon 4: 2 known disease-causing sitesExon 5: 4 known disease-causing sitesExon 6: 5 known disease-causing sitesExon 7: 3 known disease-causing sitesExon 8: 6 known disease-causing sitesExon 9: 2 known disease-causing sitesExon 10: 4 known disease-causing sitesExon 11: 5 known disease-causing sitesExon 12: 3 known disease-causing sitesExon 13: 3 known disease-causing sitesExon 14: 1 known disease-causing siteExon 1: 88,824,651–88,824,821, 171 basesExon 2: 88,833,693–88,833,722, 30 basesExon 3: 88,839,452–88,839,572, 121 basesExon 4: 88,840,865–88,840,928, 64 basesExon 5: 88,841,037–88,841,196, 160 basesExon 6: 88,841,425–88,841,514, 90 basesExon 7: 88,843,806–88,843,850, 45 basesExon 8: 88,852,971–88,853,056, 86 basesExon 9: 88,857,190–88,857,277, 88 basesExon 10: 88,861,222–88,861,332, 111 basesExon 11: 88,870,059–88,870,198, 140 basesExon 12: 88,871,549–88,871,723, 175 basesExon 13: 88,872,330–88,872,452, 123 basesExon 14: 88,875,026–88,875,109, 84 basesExon 15: 88,877,294–88,877,988, 695 bases1510155′3′

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 2.2 kb of the gene's 53.3 kb; 1,548 of those bases code for the protein.

How a genome test reads TTC8

68

positions in TTC8 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 53.3 kb of TTC8, introns included, not only the 2.2 kb of exons.

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

APA

Dante Labs. (n.d.). TTC8 gene: tetratricopeptide repeat domain 8. Retrieved 16 October 2026, from https://dantelabs.com/genes/ttc8

Vancouver

Dante Labs. TTC8 gene: tetratricopeptide repeat domain 8 [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/ttc8

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