SGCA Gene - Sarcoglycan Alpha
Genetic and Functional Insights into the Alpha-Sarcoglycan Gene
Gene Information Card
| Symbol | SGCA |
|---|---|
| Full Name | Sarcoglycan Alpha |
| Gene Type | Protein coding |
| Chromosomal Location | 17q21.33 |
| NCBI Gene ID | 7157 ncbi.nlm.nih.gov/gene/7157 |
| Ensembl ID | ENSG00000108823 |
| UniProt ID | Q16586 |
| OMIM ID | 600119 |
| HGNC ID | 10805 |
| Aliases | ADL, DAG2, LGMD2D, 50DAG, A3G, DAG, alpha-SG |
Description
The SGCA gene encodes alpha-sarcoglycan, a transmembrane glycoprotein component of the dystrophin-glycoprotein complex (DGC). This complex links the cytoskeleton to the extracellular matrix in muscle fibers, providing structural integrity. Mutations in SGCA cause autosomal recessive limb-girdle muscular dystrophy R3 (LGMD R3, formerly LGMD2D), characterized by progressive proximal muscle weakness and wasting.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Limb-girdle muscular dystrophy R3 (LGMD R3) | Loss-of-function mutations in SGCA disrupt the sarcoglycan complex, destabilizing the DGC and leading to muscle fiber degeneration. | ClinVar, OMIM #600119 |
| Dilated cardiomyopathy (rare association) | Secondary cardiac involvement in some LGMD R3 patients due to loss of sarcolemmal integrity. | ClinVar, literature reports |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 68.2 | High |
| Heart | 22.5 | Medium |
| Smooth muscle | 8.1 | Low |
| Brain | 0.3 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Skeletal muscle myotubes | 72.5 | Differentiated primary cells |
| Cardiomyocytes (iPS-derived) | 18.9 | Low expression |
| Fibroblasts | 0.2 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.229C>T (p.Arg77Cys) | Missense | Common in LGMD R3 | Disrupts sarcoglycan complex assembly |
| c.271G>A (p.Glu91Lys) | Missense | Recurrent | Reduced protein stability |
| c.850C>T (p.Arg284*) | Nonsense | Rare | Premature truncation, loss of function |
| c.101G>A (p.Trp34*) | Nonsense | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Most SGCA mutations are loss-of-function, leading to reduced or absent alpha-sarcoglycan protein, destabilizing the sarcoglycan complex and DGC.
Gain of Function (GOF)
No gain-of-function mutations reported for SGCA.
Dominant Negative (DN)
No dominant-negative mutations reported; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Dystrophin-associated glycoprotein complex (DGC) pathway
• Striated muscle contraction pathway
Protein Summary
Alpha-sarcoglycan (UniProt Q16586) is a 50 kDa transmembrane protein with a single transmembrane domain, a short intracellular C-terminus, and a large extracellular N-terminal domain. It is a core component of the sarcoglycan complex (alpha, beta, gamma, delta) within the DGC. The protein is N-glycosylated and interacts with dystrophin and other sarcoglycans to maintain sarcolemmal stability. Loss of alpha-sarcoglycan leads to secondary reduction of other sarcoglycans and muscle fiber necrosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SGCA Knockout HEK293 Cell Line | EDJ-KQ5740 | Human | 6442 | Details Get a Quote |
| SGCA Knockout A-549 Cell Line | EDJ-KQ29138 | Human | 6442 | Details Get a Quote |
| SGCA Knockout HeLa Cell Line | EDJ-KQ54454 | Human | 6442 | Details Get a Quote |
| SGCA Knockout HCT 116 Cell Line | EDJ-KQ71414 | Human | 6442 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
