Quantitative Measurement of Glycosylated ⍺-Dystroglycan as a Biomarker for Disease Severity in Limb-Girdle Muscular Dystrophy Type 2I/R9

Limb-girdle muscular dystrophy type 2I (LGMD2I/R9) is caused by biallelic variants in the gene for Fukutin-related protein (FKRP), an enzyme required for proper glycosylation of α-dystroglycan (⍺DG), a critical structural protein of the dystrophin glycoprotein complex. Hypoglycosylation of αDG results in impaired function of αDG, which in turn leads to chronic myocyte injury and muscular dystrophy. The “Biomarker Development in LGMD2I/R9” (MLB-01-001) natural history study explored glycosylated ⍺DG as a muscle biomarker for LGMD2I/R9 to support clinical trial design for the development of potential therapeutics.