| HGNC Family | Tetratricopeptide repeat domain containing (TTC) |
| Name | tetratricopeptide repeat domain 21A |
| Description | Involved in flagellated sperm motility and spermatid development. Predicted to be located in cilium. Predicted to be part of intraciliary transport particle A. Implicated in spermatogenic failure 37. [provided by Alliance of Genome Resources, Mar 2025] |
| Summary |
{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nTTC21A is a gene encoding an intraflagellar transport‐associated protein characterized by multiple tetratricopeptide repeat domains that are essential for proper ciliary function. In studies of male infertility, bi-allelic mutations in TTC21A have been shown to disrupt the structural integrity of sperm flagella and the connection between the head and tail, leading to asthenoteratospermia and multiple morphological abnormalities of the sperm flagella. These defects were consistently observed in affected individuals and further validated using a Ttc21a mutant mouse model, underscoring the gene’s critical role in spermatogenesis by ensuring the proper assembly and maintenance of ciliary structures essential for sperm motility."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn addition to its established role in ciliary function and reproductive health, emerging evidence suggests that TTC21A may also participate in carcinogenic processes. Investigations into lung adenocarcinoma have explored associations between TTC21A expression and the tumor microenvironment, particularly in relation to immune infiltration and overall patient survival, although the underlying mechanisms remain to be fully elucidated."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nSimilarly, recent research in head and neck squamous cell carcinoma has begun to assess the potential contributions of TTC21A to tumor biology. While its precise role in this cancer type is not yet defined, these initial studies align with the broader concept that TTC21A, through its fundamental influence on ciliary functions, may be implicated in diverse pathogenic pathways including carcinogenesis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Wangjie Liu, Xiaojin He, Shenmin Yang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Bi-allelic Mutations in TTC21A Induce Asthenoteratospermia in Humans and Mice."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Am J Hum Genet (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.ajhg.2019.02.020"}], "href": "https://doi.org/10.1016/j.ajhg.2019.02.020"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "30929735"}], "href": "https://pubmed.ncbi.nlm.nih.gov/30929735"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Wei Wang, Shiqi Ren, Ziheng Wang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Increased expression of TTC21A in lung adenocarcinoma infers favorable prognosis and high immune infiltrating level."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Int Immunopharmacol (2020)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.intimp.2019.106077"}], "href": "https://doi.org/10.1016/j.intimp.2019.106077"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31812070"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31812070"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Lili Wang, Yanping Yin, Peng Liu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Identification of "}, {"type": "a", "children": [{"type": "t", "text": "i"}], "href": "i"}, {"type": "t", "text": "TTC21A"}, {"type": "a", "children": [{"type": "t", "text": "/i"}], "href": "/i"}, {"type": "t", "text": " as a Potential Prognostic Marker in Head and Neck Squamous Cell Carcinoma: "}, {"type": "a", "children": [{"type": "t", "text": "i"}], "href": "i"}, {"type": "t", "text": "In Silico"}, {"type": "a", "children": [{"type": "t", "text": "/i"}], "href": "/i"}, {"type": "t", "text": " Analysis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cancer Genomics Proteomics (2024)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.21873/cgp.20428"}], "href": "https://doi.org/10.21873/cgp.20428"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "38151293"}], "href": "https://pubmed.ncbi.nlm.nih.gov/38151293"}]}]}]}
|
| Synonyms | IFT139A, STI2 |
| Proteins | TT21A_HUMAN |
| NCBI Gene ID | 199223 |
| API | |
| Download Associations | |
| Predicted Functions |
 |
| Co-expressed Genes |
|
| Expression in Tissues and Cell Lines |
|
TTC21A has 3,645 functional associations with biological entities spanning 9 categories (molecular profile, organism, functional term, phrase or reference, chemical, disease, phenotype or trait, structural feature, cell line, cell type or tissue, gene, protein or microRNA, sequence feature) extracted from 79 datasets.
Click the + buttons to view associations for TTC21A from the datasets below.
If available, associations are ranked by standardized value
| Dataset | Summary | |
|---|---|---|
| Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles | tissues with high or low expression of TTC21A gene relative to other tissues from the Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles dataset. | |
| Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles | tissues with high or low expression of TTC21A gene relative to other tissues from the Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles dataset. | |
| Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles | tissue samples with high or low expression of TTC21A gene relative to other tissue samples from the Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles dataset. | |
| Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq | tissue samples with high or low expression of TTC21A gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq dataset. | |
| Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles | tissues with high or low expression of TTC21A gene relative to other tissues from the Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles dataset. | |
| BioGPS Mouse Cell Type and Tissue Gene Expression Profiles | cell types and tissues with high or low expression of TTC21A gene relative to other cell types and tissues from the BioGPS Mouse Cell Type and Tissue Gene Expression Profiles dataset. | |
| CCLE Cell Line Gene CNV Profiles | cell lines with high or low copy number of TTC21A gene relative to other cell lines from the CCLE Cell Line Gene CNV Profiles dataset. | |
| CCLE Cell Line Gene Expression Profiles | cell lines with high or low expression of TTC21A gene relative to other cell lines from the CCLE Cell Line Gene Expression Profiles dataset. | |
| CellMarker Gene-Cell Type Associations | cell types associated with TTC21A gene from the CellMarker Gene-Cell Type Associations dataset. | |
| ChEA Transcription Factor Binding Site Profiles | transcription factor binding site profiles with transcription factor binding evidence at the promoter of TTC21A gene from the CHEA Transcription Factor Binding Site Profiles dataset. | |
| ChEA Transcription Factor Targets | transcription factors binding the promoter of TTC21A gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets dataset. | |
| ChEA Transcription Factor Targets 2022 | transcription factors binding the promoter of TTC21A gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets 2022 dataset. | |
| COMPARTMENTS Curated Protein Localization Evidence Scores 2025 | cellular components containing TTC21A protein from the COMPARTMENTS Curated Protein Localization Evidence Scores 2025 dataset. | |
| COMPARTMENTS Experimental Protein Localization Evidence Scores 2025 | cellular components containing TTC21A protein in low- or high-throughput protein localization assays from the COMPARTMENTS Experimental Protein Localization Evidence Scores 2025 dataset. | |
| COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 | cellular components co-occuring with TTC21A protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset. | |
| COSMIC Cell Line Gene CNV Profiles | cell lines with high or low copy number of TTC21A gene relative to other cell lines from the COSMIC Cell Line Gene CNV Profiles dataset. | |
| COSMIC Cell Line Gene Mutation Profiles | cell lines with TTC21A gene mutations from the COSMIC Cell Line Gene Mutation Profiles dataset. | |
| CTD Gene-Chemical Interactions | chemicals interacting with TTC21A gene/protein from the curated CTD Gene-Chemical Interactions dataset. | |
| CTD Gene-Disease Associations | diseases associated with TTC21A gene/protein from the curated CTD Gene-Disease Associations dataset. | |
| dbGAP Gene-Trait Associations | traits associated with TTC21A gene in GWAS and other genetic association datasets from the dbGAP Gene-Trait Associations dataset. | |
| DepMap CRISPR Gene Dependency | cell lines with fitness changed by TTC21A gene knockdown relative to other cell lines from the DepMap CRISPR Gene Dependency dataset. | |
| DISEASES Experimental Gene-Disease Association Evidence Scores 2025 | diseases associated with TTC21A gene in GWAS datasets from the DISEASES Experimental Gene-Disease Assocation Evidence Scores 2025 dataset. | |
| DISEASES Text-mining Gene-Disease Association Evidence Scores | diseases co-occuring with TTC21A gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores dataset. | |
| DISEASES Text-mining Gene-Disease Association Evidence Scores 2025 | diseases co-occuring with TTC21A gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores 2025 dataset. | |
| DisGeNET Gene-Disease Associations | diseases associated with TTC21A gene in GWAS and other genetic association datasets from the DisGeNET Gene-Disease Associations dataset. | |
| DisGeNET Gene-Phenotype Associations | phenotypes associated with TTC21A gene in GWAS and other genetic association datasets from the DisGeNET Gene-Phenoptype Associations dataset. | |
| ENCODE Histone Modification Site Profiles | histone modification site profiles with high histone modification abundance at TTC21A gene from the ENCODE Histone Modification Site Profiles dataset. | |
| ENCODE Transcription Factor Binding Site Profiles | transcription factor binding site profiles with transcription factor binding evidence at the promoter of TTC21A gene from the ENCODE Transcription Factor Binding Site Profiles dataset. | |
| ENCODE Transcription Factor Targets | transcription factors binding the promoter of TTC21A gene in ChIP-seq datasets from the ENCODE Transcription Factor Targets dataset. | |
| ESCAPE Omics Signatures of Genes and Proteins for Stem Cells | PubMedIDs of publications reporting gene signatures containing TTC21A from the ESCAPE Omics Signatures of Genes and Proteins for Stem Cells dataset. | |
| GAD Gene-Disease Associations | diseases associated with TTC21A gene in GWAS and other genetic association datasets from the GAD Gene-Disease Associations dataset. | |
| GeneSigDB Published Gene Signatures | PubMedIDs of publications reporting gene signatures containing TTC21A from the GeneSigDB Published Gene Signatures dataset. | |
| GEO Signatures of Differentially Expressed Genes for Diseases | disease perturbations changing expression of TTC21A gene from the GEO Signatures of Differentially Expressed Genes for Diseases dataset. | |
| GEO Signatures of Differentially Expressed Genes for Gene Perturbations | gene perturbations changing expression of TTC21A gene from the GEO Signatures of Differentially Expressed Genes for Gene Perturbations dataset. | |
| GEO Signatures of Differentially Expressed Genes for Kinase Perturbations | kinase perturbations changing expression of TTC21A gene from the GEO Signatures of Differentially Expressed Genes for Kinase Perturbations dataset. | |
| GEO Signatures of Differentially Expressed Genes for Small Molecules | small molecule perturbations changing expression of TTC21A gene from the GEO Signatures of Differentially Expressed Genes for Small Molecules dataset. | |
| GEO Signatures of Differentially Expressed Genes for Transcription Factor Perturbations | transcription factor perturbations changing expression of TTC21A gene from the GEO Signatures of Differentially Expressed Genes for Transcription Factor Perturbations dataset. | |
| GEO Signatures of Differentially Expressed Genes for Viral Infections | virus perturbations changing expression of TTC21A gene from the GEO Signatures of Differentially Expressed Genes for Viral Infections dataset. | |
| GO Biological Process Annotations 2023 | biological processes involving TTC21A gene from the curated GO Biological Process Annotations 2023 dataset. | |
| GO Biological Process Annotations 2025 | biological processes involving TTC21A gene from the curated GO Biological Process Annotations2025 dataset. | |
| GTEx eQTL 2025 | SNPs regulating expression of TTC21A gene from the GTEx eQTL 2025 dataset. | |
| GTEx Tissue Gene Expression Profiles | tissues with high or low expression of TTC21A gene relative to other tissues from the GTEx Tissue Gene Expression Profiles dataset. | |
| GTEx Tissue Sample Gene Expression Profiles | tissue samples with high or low expression of TTC21A gene relative to other tissue samples from the GTEx Tissue Sample Gene Expression Profiles dataset. | |
| GTEx Tissue-Specific Aging Signatures | tissue samples with high or low expression of TTC21A gene relative to other tissue samples from the GTEx Tissue-Specific Aging Signatures dataset. | |
| GWAS Catalog SNP-Phenotype Associations 2025 | phenotypes associated with TTC21A gene in GWAS datasets from the GWAS Catalog SNP-Phenotype Associations 2025 dataset. | |
| GWASdb SNP-Disease Associations | diseases associated with TTC21A gene in GWAS and other genetic association datasets from the GWASdb SNP-Disease Associations dataset. | |
| GWASdb SNP-Phenotype Associations | phenotypes associated with TTC21A gene in GWAS datasets from the GWASdb SNP-Phenotype Associations dataset. | |
| Heiser et al., PNAS, 2011 Cell Line Gene Expression Profiles | cell lines with high or low expression of TTC21A gene relative to other cell lines from the Heiser et al., PNAS, 2011 Cell Line Gene Expression Profiles dataset. | |
| HPA Cell Line Gene Expression Profiles | cell lines with high or low expression of TTC21A gene relative to other cell lines from the HPA Cell Line Gene Expression Profiles dataset. | |
| HPA Tissue Gene Expression Profiles | tissues with high or low expression of TTC21A gene relative to other tissues from the HPA Tissue Gene Expression Profiles dataset. | |
| HPA Tissue Protein Expression Profiles | tissues with high or low expression of TTC21A protein relative to other tissues from the HPA Tissue Protein Expression Profiles dataset. | |
| HPA Tissue Sample Gene Expression Profiles | tissue samples with high or low expression of TTC21A gene relative to other tissue samples from the HPA Tissue Sample Gene Expression Profiles dataset. | |
| InterPro Predicted Protein Domain Annotations | protein domains predicted for TTC21A protein from the InterPro Predicted Protein Domain Annotations dataset. | |
| JASPAR Predicted Human Transcription Factor Targets 2025 | transcription factors regulating expression of TTC21A gene predicted using known transcription factor binding site motifs from the JASPAR Predicted Human Transcription Factor Targets dataset. | |
| JASPAR Predicted Mouse Transcription Factor Targets 2025 | transcription factors regulating expression of TTC21A gene predicted using known transcription factor binding site motifs from the JASPAR Predicted Mouse Transcription Factor Targets 2025 dataset. | |
| JASPAR Predicted Transcription Factor Targets | transcription factors regulating expression of TTC21A gene predicted using known transcription factor binding site motifs from the JASPAR Predicted Transcription Factor Targets dataset. | |
| Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene CNV Profiles | cell lines with high or low copy number of TTC21A gene relative to other cell lines from the Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene CNV Profiles dataset. | |
| Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene Expression Profiles | cell lines with high or low expression of TTC21A gene relative to other cell lines from the Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene Expression Profiles dataset. | |
| Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene Mutation Profiles | cell lines with TTC21A gene mutations from the Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene Mutation Profiles dataset. | |
| KnockTF Gene Expression Profiles with Transcription Factor Perturbations | transcription factor perturbations changing expression of TTC21A gene from the KnockTF Gene Expression Profiles with Transcription Factor Perturbations dataset. | |
| LOCATE Predicted Protein Localization Annotations | cellular components predicted to contain TTC21A protein from the LOCATE Predicted Protein Localization Annotations dataset. | |
| MGI Mouse Phenotype Associations 2023 | phenotypes of transgenic mice caused by TTC21A gene mutations from the MGI Mouse Phenotype Associations 2023 dataset. | |
| MiRTarBase microRNA Targets | microRNAs targeting TTC21A gene in low- or high-throughput microRNA targeting studies from the MiRTarBase microRNA Targets dataset. | |
| MotifMap Predicted Transcription Factor Targets | transcription factors regulating expression of TTC21A gene predicted using known transcription factor binding site motifs from the MotifMap Predicted Transcription Factor Targets dataset. | |
| MSigDB Signatures of Differentially Expressed Genes for Cancer Gene Perturbations | gene perturbations changing expression of TTC21A gene from the MSigDB Signatures of Differentially Expressed Genes for Cancer Gene Perturbations dataset. | |
| NIBR DRUG-seq U2OS MoA Box Gene Expression Profiles | drug perturbations changing expression of TTC21A gene from the NIBR DRUG-seq U2OS MoA Box dataset. | |
| PerturbAtlas Signatures of Differentially Expressed Genes for Gene Perturbations | gene perturbations changing expression of TTC21A gene from the PerturbAtlas Signatures of Differentially Expressed Genes for Gene Perturbations dataset. | |
| PerturbAtlas Signatures of Differentially Expressed Genes for Mouse Gene Perturbations | gene perturbations changing expression of TTC21A gene from the PerturbAtlas Signatures of Differentially Expressed Genes for Gene Perturbations dataset. | |
| Roadmap Epigenomics Cell and Tissue Gene Expression Profiles | cell types and tissues with high or low expression of TTC21A gene relative to other cell types and tissues from the Roadmap Epigenomics Cell and Tissue Gene Expression Profiles dataset. | |
| Roadmap Epigenomics Histone Modification Site Profiles | histone modification site profiles with high histone modification abundance at TTC21A gene from the Roadmap Epigenomics Histone Modification Site Profiles dataset. | |
| RummaGEO Drug Perturbation Signatures | drug perturbations changing expression of TTC21A gene from the RummaGEO Drug Perturbation Signatures dataset. | |
| RummaGEO Gene Perturbation Signatures | gene perturbations changing expression of TTC21A gene from the RummaGEO Gene Perturbation Signatures dataset. | |
| Tabula Sapiens Gene-Cell Associations | cell types with high or low expression of TTC21A gene relative to other cell types from the Tabula Sapiens Gene-Cell Associations dataset. | |
| TargetScan Predicted Nonconserved microRNA Targets | microRNAs regulating expression of TTC21A gene predicted using nonconserved miRNA seed sequences from the TargetScan Predicted Nonconserved microRNA Targets dataset. | |
| TCGA Signatures of Differentially Expressed Genes for Tumors | tissue samples with high or low expression of TTC21A gene relative to other tissue samples from the TCGA Signatures of Differentially Expressed Genes for Tumors dataset. | |
| TISSUES Curated Tissue Protein Expression Evidence Scores 2025 | tissues with high expression of TTC21A protein from the TISSUES Curated Tissue Protein Expression Evidence Scores 2025 dataset. | |
| TISSUES Experimental Tissue Protein Expression Evidence Scores | tissues with high expression of TTC21A protein in proteomics datasets from the TISSUES Experimental Tissue Protein Expression Evidence Scores dataset. | |
| TISSUES Experimental Tissue Protein Expression Evidence Scores 2025 | tissues with high expression of TTC21A protein in proteomics datasets from the TISSUES Experimental Tissue Protein Expression Evidence Scores 2025 dataset. | |
| TISSUES Text-mining Tissue Protein Expression Evidence Scores 2025 | tissues co-occuring with TTC21A protein in abstracts of biomedical publications from the TISSUES Text-mining Tissue Protein Expression Evidence Scores 2025 dataset. | |
