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BCAP31
B cell receptor associated protein 31
The BCAP31 gene provides instructions for making a protein involved in the endoplasmic reticulum, playing a role in protein transport and maintaining cellular integrity. The BCAP31 gene encodes a protein integral to the endoplasmic reticulum membrane, where it assists in the trafficking of other proteins within the cell.
BCAP31 is located on the long (q) arm of chromosome X, at band Xq28. Arm ratio per GRCh38 - banding schematic.
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Clinical tests that include this
Overview
The BCAP31 gene, also known as B cell receptor associated protein 31, is crucial for normal cellular function, particularly within the endoplasmic reticulum (ER). The protein it produces is an integral membrane protein that helps manage the movement and processing of other proteins. Understanding BCAP31's role can offer insight into various conditions that arise when this function is disrupted.
What the gene does
The BCAP31 protein is located in the membrane of the endoplasmic reticulum, a network within cells responsible for synthesising and packaging proteins and lipids. Its primary function involves mediating the transport of newly synthesised proteins from the ER to other cellular compartments, such as the Golgi apparatus. Specifically, BCAP31 acts as a cargo receptor and is involved in the retention and retrieval of certain proteins within the ER, ensuring they are correctly folded and processed before being dispatched. Its activity is vital for maintaining the ER's critical role in protein quality control.
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Chromosome location
The BCAP31 gene is situated on the long arm of the X chromosome, specifically at position Xq28. This chromosomal location means that the gene is part of the genetic material inherited in an X-linked pattern. The Xq28 region is known to contain several genes associated with various inherited conditions.
Protein structure
The BCAP31 protein is composed of 246 amino acids. It features distinct functional regions that contribute to its role in the endoplasmic reticulum. Key structural elements include a Coiled coil domain, spanning amino acids 165-237, which is often involved in protein-protein interactions. Additionally, a Di-lysine motif (amino acids 243-246) is present at the C-terminus, which typically plays a role in the retrieval of ER proteins from post-ER compartments.
Key variants
Variations within the BCAP31 gene can affect the structure and function of the encoded protein. These genetic changes can range from single nucleotide differences to larger alterations. Depending on their nature and location, such variants may impact the protein's ability to facilitate protein transport and cellular homeostasis, leading to diverse health consequences.
Sample of pathogenic variants
10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.
| Variant (HGVS) | Protein change | Classification | Evidence | Associated condition |
|---|---|---|---|---|
c.365_366del | p.Leu122fs | Pathogenic | ★★☆☆ | Inborn genetic diseases |
g.(?_152980977)_(152981164_?)del | - | Pathogenic | ★☆☆☆ | not provided |
c.295del | p.Ala99fs | Pathogenic | ★☆☆☆ | not provided |
c.309_310del | p.Tyr104fs | Pathogenic | ★☆☆☆ | not provided |
c.341+2T>G | - | Pathogenic | ★☆☆☆ | not provided |
c.400G>T | p.Glu134Ter | Pathogenic | ★☆☆☆ | not provided |
c.415C>T | p.Gln139Ter | Pathogenic | ★☆☆☆ | Severe motor and intellectual disabilities-sensorineural deafness-dystonia syndrome |
c.526A>T | p.Lys176Ter | Pathogenic | ★☆☆☆ | not provided |
c.91A>T | p.Arg31Ter | Pathogenic | ★☆☆☆ | not provided |
c.-44-270C>A | S36* | Pathogenic | - | Severe motor and intellectual disabilities-sensorineural deafness-dystonia syndrome |
Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.
Associated conditions
Genetic changes in the BCAP31 gene have been associated with a spectrum of inherited disorders. These conditions often relate to disruptions in cellular protein trafficking and endoplasmic reticulum function. The clinical presentations can be varied, underscoring the protein's widespread importance in different cell types and tissues.
No disease links recorded for this gene in our reference set.
UK clinical status
In the UK, the BCAP31 gene is included in several NHS Genomic Medicine Service national test panels. These green-rated panels, indicating strong evidence for the gene's involvement in the mentioned conditions, include panels for Childhood onset dystonia, chorea or related movement disorder (R57), DDG2P, Early onset dystonia, Foetal anomalies (R21), Inherited white matter disorders, Intellectual disability (R29), and White matter disorders and cerebral calcification - narrow panel. This inclusion highlights its recognised clinical significance.
Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory
Frequently asked questions
What is the main function of the BCAP31 gene?
The BCAP31 gene provides instructions for a protein that is integral to the endoplasmic reticulum membrane. This protein is critical for transporting other proteins within the cell and ensuring their proper folding and processing.
What part of the cell does the BCAP31 protein primarily function in?
The BCAP31 protein primarily functions within the endoplasmic reticulum (ER), which is a key cellular organelle involved in the synthesis and packaging of proteins and lipids.
How might variations in the BCAP31 gene affect health?
Variations in the BCAP31 gene can disrupt the protein's normal function in protein transport and ER homeostasis. This can lead to a range of inherited conditions affecting various bodily systems, as evidenced by its inclusion in several NHS clinical panels.