FKRP encodes fukutin related protein (495 aa). Catalyzes the transfer of a ribitol 5-phosphate from CDP-L-ribitol to the ribitol 5-phosphate previously attached by FKTN/fukutin to the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan (DAG1). Highest expression in Pituitary (19.7 TPM) and Uterus (18.0 TPM).

Autosomal recessive limb-girdle muscular dystrophy type 2I is associated with mutations in the FKRP gene on chromosome 19.

The FKRP protein participates in POMGNT1 catalyzes FKRP:FKTN:RXYLT1 formation and FKTN transfers RboP to GalNAc-GlcNAc-ManP-DAG1 pathways.

FKRP is classified as a druggable target (Druggable Genome category) with score 0.0.

Genetic testing for FKRP is available. Testing is considered confirmatory for diagnosis.

No approved treatments are currently available for autosomal recessive limb-girdle muscular dystrophy type 2I. An additional 1 compound holds orphan drug designation.

Orphan Drug Designations

While no drugs are FDA-approved specifically for autosomal recessive limb-girdle muscular dystrophy type 2I, some of the following designated compounds may be used off-label in clinical practice. Treatment decisions should be made in consultation with a specialist familiar with this condition.

The following drugs have received orphan drug designation from the FDA for autosomal recessive limb-girdle muscular dystrophy type 2I. Orphan designation reflects regulatory interest and does not indicate approval for treatment.

ribitol is referenced in active clinical trials for autosomal recessive limb-girdle muscular dystrophy type 2I (designated 2019).

Phenotype severity distribution: 4 very common features, 6 common features.

Estimated prevalence: 1-9 in 100,000 (Uncommon).

6 clinical trials registered, 2 recruiting. Interventions under study include drug therapy, other interventions, and gene therapy. Pipeline includes 2 PHASE3, 1 PHASE2, 1 PHASE1. Research is sponsored by a mix of industry and academic institutions.

101 publications have been identified in PubMed for autosomal recessive limb-girdle muscular dystrophy type 2I. Kisho has analyzed 29 by research type. Research spans Review / Meta-Analysis (66%), Epidemiology / Natural History (24%), and Clinical Trial Publication (10%).

Recent Publications

• Li S (2026). [PMID: 41379706](https://pubmed.ncbi.nlm.nih.gov/41379706/). *J Fam Psychol*. [Review / Meta-Analysis]

• Flynn P (2025). [PMID: 40578827](https://pubmed.ncbi.nlm.nih.gov/40578827/). *Sleep*. [Review / Meta-Analysis]

• Angelini C (2025). [PMID: 40183440](https://pubmed.ncbi.nlm.nih.gov/40183440/). *Acta Myol*. [Review / Meta-Analysis]

• Silverstein M (2025). [PMID: 39780401](https://pubmed.ncbi.nlm.nih.gov/39780401/). *The Gerontologist*. [Review / Meta-Analysis]

• Woodward LJ (2025). [PMID: 39491338](https://pubmed.ncbi.nlm.nih.gov/39491338/). *Acta paediatrica (Oslo, Norway : 1992)*. [Review / Meta-Analysis]

• Marshall KH (2025). [PMID: 39838237](https://pubmed.ncbi.nlm.nih.gov/39838237/). *Qual Life Res*. [Epidemiology / Natural History]

• McMahon EL (2025). [PMID: 41206319](https://pubmed.ncbi.nlm.nih.gov/41206319/). *Current problems in pediatric and adolescent health care*. [Review / Meta-Analysis]

• Taki S (2025). [PMID: 40785243](https://pubmed.ncbi.nlm.nih.gov/40785243/). *Int J Nurs Pract*. [Clinical Trial Publication]

• Campbell JI (2025). [PMID: 39509188](https://pubmed.ncbi.nlm.nih.gov/39509188/). *Current opinion in pediatrics*. [Review / Meta-Analysis]

• Buckeridge K (2024). [PMID: 39417318](https://pubmed.ncbi.nlm.nih.gov/39417318/). *Int J Lang Commun Disord*. [Review / Meta-Analysis]