Which statement correctly describes the inheritance patterns of FSHD1 and LGMD2I?

• A. FSHD1 is autosomal dominant and LGMD2I is autosomal recessive
• B. FSHD1 is autosomal recessive and LGMD2I is autosomal dominant
• C. Both are autosomal dominant
• D. Both are autosomal recessive

Answer: (A)

FSHD1 and LGMD2I have different inheritance patterns, which is why this pairing is the correct description. FSHD1 is inherited in an autosomal dominant fashion, meaning a single mutated allele can be enough to predispose to disease, though the expression can vary widely and penetrance is incomplete. LGMD2I, on the other hand, is autosomal recessive, requiring two mutated copies of the FKRP gene for the disease to manifest, so carriers with one mutated copy typically do not show symptoms. Therefore, the statement that FSHD1 is autosomal dominant and LGMD2I is autosomal recessive accurately reflects how each condition is inherited. The other patterns—recessive for FSHD1 or dominant for LGMD2I, or both being the same—do not fit these disorders.