Pathogenic biallelic variants in POGLUT1 were linked to limb-girdle muscular dystrophy R21 (LGMD R21), a new type of LGMD featuring pelvic and shoulder girdle weakness, variable age of onset, slowly progressive course, and “inside-to-outside” fatty degeneration pattern in muscle magnetic resonance imaging (MRI). We describe a 54-year-old female with an infantile-onset, slowly progressive, pelvicgirdle myopathy,...