Limb-Girdle Muscular Dystrophy Type 2I (LGMDR9)
Summary
LGMD2I (LGMDR9) is one of the dystroglycanopathies — conditions where defective glycosylation of alpha-dystroglycan disrupts the connection between muscle cells and their surrounding matrix. FKRP encodes a glycosyltransferase involved in this process.
Practical takeaway
The L276I variant is relatively common in Northern Europeans. Partner carrier testing is straightforward. Realised does not calculate reproductive risk or advise on reproductive decisions.
Evidence detail
What Carrier Status Means For You
You are not affected. One working copy of FKRP is sufficient. Standard 25/50/25 recessive inheritance applies. If your partner also carries an FKRP variant, the specific combination determines severity.
Population Context
L276I is the most common FKRP variant in Europe, with particularly high carrier frequencies in Scandinavian, British, and German populations. LGMD2I may be the most common LGMD in some Northern European countries.
Limitations
23andMe tests 1 FKRP variant. L276I is the most common but other variants cause more severe phenotypes. Comprehensive dystroglycanopathy panels recommended for broader testing.