FKTN (Fukutin) Gene
Essential for α-Dystroglycan Glycosylation; Mutations Cause Muscular Dystrophy and Cardiomyopathy
Gene Information Card
| Symbol | FKTN |
|---|---|
| Full Name | fukutin |
| Gene Type | protein-coding |
| Chromosomal Location | 9q31.2 |
| NCBI Gene ID | 2218 ncbi.nlm.nih.gov/gene/2218 |
| Ensembl ID | ENSG00000106692 |
| UniProt ID | O75072 |
| OMIM ID | 607440 |
| HGNC ID | 3622 |
| Aliases | FCMD, MGC126600, MGC126602, fukutin |
Description
The FKTN gene encodes fukutin, a putative glycosyltransferase localized to the Golgi apparatus. It is essential for the O-mannosylation of α-dystroglycan, a key component of the dystrophin-glycoprotein complex. Loss of fukutin function disrupts α-dystroglycan ligand binding, leading to muscular dystrophy and brain/eye abnormalities.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Fukuyama congenital muscular dystrophy (FCMD) | Loss of fukutin function reduces α-dystroglycan glycosylation, impairing basement membrane adhesion | OMIM #253800; NCBI GeneReviews |
| Limb-girdle muscular dystrophy type 2R (LGMD2R) | Hypomorphic FKTN mutations cause milder glycosylation defects, leading to progressive proximal muscle weakness | OMIM #613152; ClinVar |
| Dilated cardiomyopathy 1X (CMD1X) | Cardiac-specific fukutin deficiency disrupts dystroglycan function in cardiomyocytes | OMIM #611615; NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 8.2 | Medium |
| Skeletal Muscle | 6.5 | Medium |
| Brain | 5.1 | Low |
| Liver | 3.8 | Low |
| Kidney | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 7.1 | Cervical carcinoma |
| K562 | 5.3 | Leukemia |
| HepG2 | 4.9 | Hepatocellular carcinoma |
| A549 | 6.0 | Lung carcinoma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.647_648insG (p.Leu216Alafs*38) | Frameshift | Common in FCMD (founder mutation in Japanese) | Loss of function |
| c.919G>A (p.Gly307Arg) | Missense | Rare | Impaired glycosyltransferase activity |
| c.1167A>G (p.Thr389Ala) | Missense | Rare | Reduced protein stability |
Mutation functional classification
Loss of Function (LOF)
Most FKTN mutations (frameshift, nonsense, splice-site) cause complete or partial loss of fukutin enzymatic activity, leading to hypoglycosylation of α-dystroglycan.
Gain of Function (GOF)
No evidence of gain-of-function mutations in FKTN.
Dominant Negative (DN)
Not reported; FKTN mutations are typically recessive.
View complete mutation data：
Gene Ontology (GO)
| • Golgi membrane (GO:0000139) | • acetylglucosaminyltransferase activity (GO:0008375) |
| • protein glycosylation (GO:0006486) | • glycosyltransferase activity (GO:0016757) |
| • Golgi apparatus (GO:0005794) |
Pathways
• O-mannosyl glycan biosynthesis (Reactome R-HSA-5173105)
• Dystroglycan-related adhesion (KEGG hsa05415)
Protein Summary
Fukutin is a 461-amino acid type II transmembrane protein localized to the Golgi. It functions as a ribitol 5-phosphate transferase, adding ribitol phosphate to α-dystroglycan during O-mannosylation. This modification is critical for binding extracellular matrix proteins such as laminin. Defects in fukutin cause a spectrum of muscular dystrophies with variable severity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| FKTN Knockout HEK293 Cell Line | EDJ-KQ2940 | Human | 2218 | Details Get a Quote |
| FKTN Knockout A-549 Cell Line | EDJ-KQ24057 | Human | 2218 | Details Get a Quote |
| FKTN Knockout HCT 116 Cell Line | EDJ-KQ24058 | Human | 2218 | Details Get a Quote |
| FKTN Knockout HeLa Cell Line | EDJ-KQ24059 | Human | 2218 | Details Get a Quote |
