Muscle phosphorylase b kinase deficiency revisited.
Muscle phosphorylase b kinase (PHK) deficiency (glycogenosis type VIII) is a rare disorder caused by mutations in the PHKA1 gene encoding the alpha(M) subunit of PHK. Only 5 patients with molecular defects in the X-linked PHKA1 gene have been described until now, and they all presented with exercise intolerance. Here, we report a patient with a new mutation in the PHKA1 gene who presented with PHK deficiency, cognitive impairment, but no overt myopathy. This report supports the concept that PHK deficiency is a mild metabolic myopathy and suggests that PHK mutations may interfere with normal brain function.
Echaniz-Laguna
Andoni
A
Département de Neurologie, Hôpital Civil, BP426, 67091 Strasbourg, France. Echaniz-Laguna@medecine.u-strasbg.fr
Akman
Hasan O
HO
Mohr
Michel
M
Tranchant
Christine
C
Talmant-Verbist
Violaine
V
Rolland
Marie-Odile
MO
Dimauro
Salvatore
S
D000328:Adult; D000595:Amino Acid Sequence / Q000235:genetics; D001706:Biopsy; D001921:Brain / Q000201:enzymology / Q000503:physiopathology; D018389:Codon, Nonsense / Q000235:genetics; D003072:Cognition Disorders / Q000201:enzymology* / Q000235:genetics* / Q000503:physiopathology; D003402:Creatine Kinase / Q000097:blood; D004252:DNA Mutational Analysis; D004576:Electromyography; D017079:Exercise Tolerance / Q000235:genetics; D006012:Glycogen Storage Disease Type V / Q000150:complications / Q000201:enzymology* / Q000235:genetics*; D006801:Humans; D008607:Intellectual Disability / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology; D007360:Intelligence / Q000235:genetics; D008297:Male; D018908:Muscle Weakness / Q000201:enzymology / Q000235:genetics; D018482:Muscle, Skeletal / Q000201:enzymology / Q000503:physiopathology; D010764:Phosphorylase Kinase / Q000172:deficiency* / Q000235:genetics*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism
D018389:Codon, Nonsense; D021122:Protein Subunits; D010764:Phosphorylase Kinase; D003402:Creatine Kinase