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TTC7A
tetratricopeptide repeat domain 7A
TTC7A is located on the short (p) arm of chromosome 2, at band 2p21. Arm ratio per GRCh38 - banding schematic.
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Overview
TTC7A (tetratricopeptide repeat domain 7A) is a human gene located on chromosome 2 that encodes a protein characterised by the presence of tetratricopeptide repeat motifs. These structural elements are commonly found in proteins involved in cellular regulation and molecular scaffolding, where they facilitate interactions between different protein partners. Although the full biological function of TTC7A remains incompletely understood, research suggests the protein plays a role in maintaining normal intestinal epithelial architecture and immune cell development. Variants in TTC7A have been identified in individuals with severe, early-onset conditions affecting the gastrointestinal system and immune response, highlighting the gene's importance in human health.
What the gene does
The TTC7A protein is predicted to participate in cellular processes through its tetratricopeptide repeat domains, which typically enable proteins to bind to other molecules and coordinate multi-protein complexes. Evidence suggests TTC7A may influence the regulation of cell-cell junctions within the intestinal lining, contributing to the structural integrity of the epithelial barrier that separates the gut contents from underlying tissues. The protein may also have a role in signalling pathways that govern immune cell maturation and function, although the specific molecular mechanisms remain an active area of study. Loss of normal TTC7A activity appears to disrupt both epithelial homeostasis and immune system development, suggesting the protein operates at the interface of these two critical systems. Further research is needed to fully characterise the biochemical pathways in which TTC7A participates and how the protein coordinates its various cellular functions.
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Chromosome location
TTC7A is located on the short arm of chromosome 2 at position 2p21. This chromosomal region contains multiple genes involved in diverse biological processes. The precise number of exons encoding TTC7A and detailed structural features of the genomic locus have not been comprehensively annotated in public databases at this time.
Protein structure
Domain architecture has not been experimentally characterised in detail for this protein. The TTC7A designation reflects the presence of tetratricopeptide repeat motifs within the amino acid sequence, though the precise number, positioning, and functional significance of individual repeat units have not been fully mapped through structural studies.
Key variants
Genetic variants in TTC7A encompass a range of changes, including missense substitutions, nonsense mutations that introduce premature stop codons, and deletions or insertions that disrupt the reading frame. The inheritance pattern associated with TTC7A-related conditions can vary depending on the specific disorder and the nature of the variants involved. Pathogenic variants are typically rare in the general population, and their impact on protein function likely depends on which region of the gene is affected and whether any residual protein activity remains.
No pathogenic or likely-pathogenic ClinVar variants recorded yet for this gene.
Associated conditions
Variants in TTC7A have been associated with severe gastrointestinal and immunological phenotypes that typically present in early infancy or childhood. These conditions are characterised by features such as chronic diarrhoea, intestinal inflammation, failure to thrive, and immune system abnormalities that increase susceptibility to infections. The spectrum of associated disorders reflects the protein's apparent role in both epithelial barrier function and immune cell development. Because TTC7A-related conditions are rare and clinically heterogeneous, diagnosis often requires comprehensive genetic testing alongside detailed clinical evaluation.
No disease links recorded for this gene in our reference set.
UK clinical status
Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory
Frequently asked questions
What does the TTC7A gene do?
TTC7A encodes a protein containing tetratricopeptide repeat domains, which are thought to facilitate protein-protein interactions. Research suggests the protein contributes to maintaining the structure of the intestinal lining and may play a role in immune cell development, though its precise molecular functions are still being investigated.
Are TTC7A variants common?
No, pathogenic variants in TTC7A are rare. They are typically identified in individuals with severe early-onset gastrointestinal and immune conditions, which are themselves uncommon disorders.
How are TTC7A-related conditions inherited?
The inheritance pattern for TTC7A-related conditions can vary. Many cases follow an autosomal recessive pattern, meaning an affected individual inherits a pathogenic variant from each parent. Genetic counselling can help families understand the specific inheritance pattern relevant to their situation.