TTC8

Chr 14q31.3

tetratricopeptide repeat domain 8

Aliases:: BBS8, RP51
MANE:: ENST00000380656.7

OMIM: 608132 ↗NCBI: 123016 ↗Ensembl ↗

Annotations refreshed 1 month ago.

Predicted protein structure

AlphaFold predicted structure

TTC8 · Q8TAM2

v62025-08-01

Predicted Aligned Error matrix for TTC8 — diagonal shows residue index, colour shows pairwise prediction confidence (lower is better) — Predicted Aligned Error

Mean pLDDT

84.3/ 100

Confident

541 residues

Confidence breakdown

Very high(≥ 90)56%
Confident(70–90)31%
Low(50–70)5%
Very low(< 50)9%

Open interactive 3D viewer

AlphaFold (Jumper et al., 2021) · CC BY 4.0

Clinical relevance (Genomics England PanelApp)

Diagnostic Grade (Green)

Bardet Biedl syndrome
BIALLELIC, autosomal or pseudoautosomal
DDG2P
BIALLELIC, autosomal or pseudoautosomal
Fetal anomalies
BIALLELIC, autosomal or pseudoautosomal
Intellectual disability
BIALLELIC, autosomal or pseudoautosomal
Limb disorders
BIALLELIC, autosomal or pseudoautosomal
Ophthalmological ciliopathies
BIALLELIC, autosomal or pseudoautosomal
Rare multisystem ciliopathy disorders
BIALLELIC, autosomal or pseudoautosomal
Renal ciliopathies
BIALLELIC, autosomal or pseudoautosomal

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Disease associations (Open Targets)

Bardet-Biedl syndrome
0.80
retinitis pigmentosa
0.77
Bardet-Biedl syndrome 1
0.51
Retinal dystrophy
0.51
polydactyly
0.46
hereditary disease
0.41
obesity due to melanocortin 4 receptor deficiency
0.38
Obesity
0.38
obesity disorder
0.38
Posterior column ataxia - retinitis pigmentosa
0.37

Score is the Open Targets composite evidence score (0-1). Higher = stronger gene-disease association.

Protein function (UniProt)

Tetratricopeptide repeat protein 8

The BBSome complex is thought to function as a coat complex required for sorting of specific membrane proteins to the primary cilia. The BBSome complex is required for ciliogenesis but is dispensable for centriolar satellite function. This ciliogenic function is mediated in part by the Rab8 GDP/GTP exchange factor, which localizes to the basal body and contacts the BBSome. Rab8(GTP) enters the primary cilium and promotes extension of the ciliary membrane. Firstly the BBSome associates with the ciliary membrane and binds to RAB3IP/Rabin8, the guanosyl exchange factor (GEF) for Rab8 and then the Rab8-GTP localizes to the cilium and promotes docking and fusion of carrier vesicles to the base of the ciliary membrane. The BBSome complex, together with the LTZL1, controls SMO ciliary trafficking and contributes to the sonic hedgehog (SHH) pathway regulation. Required for proper BBSome complex assembly and its ciliary localization