On this page
TRAPPC11
trafficking protein particle complex subunit 11
TRAPPC11 is located on the long (q) arm of chromosome 4, at band 4q35.1. Arm ratio per GRCh38 - banding schematic.
Explore chromosome 4 in the library →Available at Jeen Health
Clinical tests that include this
Overview
TRAPPC11 is located on chromosome 4 and encodes trafficking protein particle complex subunit 11, a component of the TRAPP complex involved in intracellular membrane transport. The TRAPP complex plays a central role in vesicle trafficking, the process by which cellular cargo moves between membrane-bound compartments such as the endoplasmic reticulum and Golgi apparatus. This trafficking is particularly important in muscle tissue, where proper protein localisation and membrane organisation are critical for maintaining structural integrity and contractile function.
Pathogenic variants in TRAPPC11 are inherited in an autosomal recessive pattern, meaning affected individuals carry two altered copies of the gene. These variants impair the TRAPP complex's ability to coordinate vesicle transport, resulting in developmental abnormalities and progressive muscle weakness characteristic of congenital muscular dystrophy.
What the gene does
The TRAPPC11 protein functions as a key structural and regulatory component of the TRAPP complex, a multi-subunit assembly that acts as a tethering factor for vesicles during membrane fusion events. The TRAPP complex identifies and captures transport vesicles, facilitating their docking at target membranes before fusion occurs. This process ensures that proteins, lipids, and other cellular components reach their correct destinations within the cell.
TRAPPC11 contributes to the stability and assembly of the larger TRAPP complex, which exists in multiple forms that participate in different trafficking routes. Research suggests that TRAPPC11-containing complexes are particularly important for anterograde transport from the endoplasmic reticulum to the Golgi apparatus, as well as for autophagy-related membrane trafficking. In muscle cells, these trafficking pathways support the continuous turnover of cellular components, maintain membrane architecture, and ensure proper distribution of structural proteins essential for muscle contraction and maintenance.
Video: Genetics 101
Chromosome location
TRAPPC11 is located on the long arm of chromosome 4 at position 35.1 (4q35.1). The gene spans a substantial genomic region and contains multiple exons that encode a relatively large protein product. The chromosomal region 4q35 is gene-rich and contains several other genes involved in diverse cellular functions, though TRAPPC11 itself has a specialised role in membrane trafficking pathways.
Protein structure
Domain architecture has not been experimentally characterised in detail for this protein. The TRAPPC11 protein comprises 1133 amino acids, making it one of the larger subunits within the TRAPP complex family. Despite its size, specific functional domains have not been comprehensively mapped, though the protein's length suggests it may contain extended regions that facilitate protein-protein interactions necessary for complex assembly and membrane tethering activity.
Key variants
Pathogenic variants in TRAPPC11 are typically loss-of-function changes that reduce or eliminate the protein's ability to participate in TRAPP complex assembly and function. These include nonsense variants that introduce premature stop codons, frameshift variants caused by small insertions or deletions, and missense variants that disrupt critical structural or functional regions. Because TRAPPC11-related conditions follow autosomal recessive inheritance, affected individuals generally carry two pathogenic variants, which may be identical (homozygous) or different (compound heterozygous).
No pathogenic or likely-pathogenic ClinVar variants recorded yet for this gene.
Associated conditions
Pathogenic variants in TRAPPC11 cause congenital muscular dystrophy, a group of inherited muscle disorders present from birth or early infancy. Affected individuals typically present with muscle weakness, delayed motor milestones, and progressive muscle wasting. The clinical presentation can vary, with some individuals experiencing predominantly limb-girdle muscle involvement affecting the shoulders and hips, while others may show more generalised muscle weakness. Intellectual disability and skeletal abnormalities have been reported in some cases, reflecting the gene's broader role in cellular membrane trafficking beyond muscle tissue.
No disease links recorded for this gene in our reference set.
Inheritance pattern
Conditions caused by pathogenic TRAPPC11 variants typically follow autosomal recessive inheritance.
When both parents are carriers, each child has a 25% chance of being affected, 50% of being a carrier, and 25% of being unaffected.
UK clinical status
TRAPPC11 is included on multiple NHS Genomic Medicine Service gene panels, reflecting its established clinical significance in diagnosing inherited muscle disorders. The gene appears on the Congenital Muscular Dystrophy panel (classified as green, version R79), the Developmental Disorders Genotype-to-Phenotype panel (DDG2P, green classification), and the Limb Girdle Muscular Dystrophies, Myofibrillar Myopathies and Distal Myopathies panel (green, version R82). A green classification indicates strong evidence supporting the gene-disease association, meaning TRAPPC11 testing is routinely available through NHS laboratories for individuals with clinical features consistent with these conditions.
Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory
Frequently asked questions
How is TRAPPC11-related muscular dystrophy inherited?
TRAPPC11-related conditions follow autosomal recessive inheritance, meaning an individual must inherit two altered copies of the gene (one from each parent) to be affected. Parents who each carry one pathogenic variant typically do not show symptoms but have a 25% chance with each pregnancy of having an affected child.
What is the TRAPP complex and why is it important for muscle cells?
The TRAPP complex is a molecular machine that directs vesicle movement within cells, ensuring proteins and membranes reach their correct destinations. In muscle cells, this trafficking is essential for maintaining the structural organisation and protein distribution needed for normal muscle contraction and long-term stability.
Can TRAPPC11 variants affect systems beyond muscle?
Yes, some individuals with TRAPPC11 variants experience features beyond muscle weakness, including intellectual disability and skeletal abnormalities. This reflects the gene's role in cellular trafficking processes that support multiple organ systems, though muscle tissue appears particularly vulnerable to TRAPPC11 dysfunction.