OMIM #612934
Inheritance - Autosomal recessive
Genitourinary Kidneys Myoglobinuria
Pigmenturia
Muscle, Soft Tissue - Muscle cramps
Exercise intolerance
Mild pelvic girdle muscle weakness
Rhabdomyolysis
Muscle biopsy shows glycogen accumulation
Laboratory Abnormalities - Increased serum creatine kinase
Increased serum ammonia
Decreased phosphoglucomutase 1 (PGM1) activity (1% of normal values)
Miscellaneous - Symptoms usually induced only by strenuous exercise
Molecular Basis - Caused by mutation in the phosphoglucomutase 1 gene (PGM1, 171900.0001)
TEXT
A number sign (#) is used with this entry because glycogen storage disease XIV (GSD14) can be caused by compound heterozygous mutation in the gene encoding phosphoglucomutase-1 (PGM1; 171900) on chromosome 1p31.
Clinical Features
Stojkovic et al. (2009) reported a 35-year-old man with recurrent muscle cramps provoked by exercise. He had had 2 episodes of dark-brown urine after strenuous exercise, suggesting rhabdomyolysis. Neurologic examination showed mild weakness of the pelvic-girdle muscles; serum creatine kinase and ammonia were increased after strenuous exercise. Muscle biopsy showed abnormal subsarcolemmal and sarcoplasmic accumulations of normally structured, free glycogen. An in vitro muscle study of anaerobic glycogenolysis and glycolysis showed a metabolic block after formation of glucose-1-phosphate and before formation of glucose-6-phosphate, indicating a phosphoglucomutase deficiency. PGM1 activity was 1% of control values. Stojkovic et al. (2009) concluded that this disorder is a rare glycolytic disorder, which should be designated glycogenosis, or glycogen storage disease, type XIV.
Molecular Genetics
In a man with exercise intolerance and episodic rhabdomyolysis, Stojkovic et al. (2009) identified compound heterozygosity for mutations in the PGM1 gene (171900.0001 and 171900.0002). Each unaffected parent carried 1 of the mutations.
