A form of limb-girdle muscular dystrophy characterized by an infantile onset of hypotonia, axial and proximal lower limb weakness (with severe weakness noted after febrile illnesses), cardiomyopathy and normal or reduced intelligence. Hypertrophy of calves, thighs, and triceps have also been reported in some cases. The disease is autosomal recessive limb-girdle muscular dystrophy type 2M (MONDO_0012699, a Monarch Disease Ontology term). Also known as: FKTN autosomal recessive limb-girdle muscular dystrophy, LGMD-FKTN related, LGMD2M, MDDGC4, autosomal recessive limb-girdle muscular dystrophy caused by mutation in FKTN, muscular dystrophy-dystroglycanopathy (limb-girdle) type C 4.