| A form of limb-girdle muscular dystrophy that can present from birth to early childhood, the disease has characteristics of hypotonia, microcephaly, mild proximal muscle weakness (leading to delayed walking and difficulty climbing stairs), mild intellectual disability and epilepsy. Additional manifestations reported in some patients include cataracts, nystagmus, cardiomyopathy, and respiratory insufficiency. The disease is caused by homozygous or compound heterozygous mutation in the GMPPB gene, which encodes the beta subunit of GDP-mannose pyrophosphorylase, on chromosome 3p21. |
