Myopathy and phosphorylase kinase deficiency caused by a mutation in the PHKA1 gene.
Wuyts W
et al.
Am J Med Genet A 2005 Feb;133A(1)82-84
Wuyts W, Reyniers E, Ceuterick C, Storm K, de Barsy T, Martin JJ.
Am J Med Genet A 2005 Feb;133A(1)82-84
Abstract: Phosphorylase kinase (PhK) deficiency is the underlying cause of variable clinical symptoms depending on the tissues involved. Until today, only a few cases of myopathy associated with muscle PhK deficiency caused by a mutation in the gene encoding the alpha subunit of phosphorylase kinase (PHKA1) have been reported. We describe a male patient with myopathy and absent muscle PhK activity caused by a frameshift mutation in the gene encoding the alpha subunit of PhK on chromosome Xq12-q13.
Assignment of human genes for phosphorylase kinase subunits alpha (PHKA) to Xq12-q13 and beta (PHKB) to 16q12-q13.
Francke U
et al.
Am J Hum Genet 1989 Aug;45(2)276-282
Francke U, Darras BT, Zander NF, Kilimann MW.
Am J Hum Genet 1989 Aug;45(2)276-282
Abstract: Phosphorylase kinase (PHK), the enzyme that activates glycogen phosphorylases in muscle, liver, and other tissues, is composed of four different subunits. Recently isolated rabbit muscle cDNAs for the larger two subunits, alpha and beta, have been used to map the location of their cognate sequences on human chromosomes. Southern blot analysis of rodent x human somatic cell hybrid panels, as well as in situ chromosomal hybridization, have provided evidence of single sites for both genes. The alpha subunit gene (PHKA) is located on the proximal long arm of the X chromosome in region Xq12-q13 near the locus for phosphoglycerate kinase (PGK1). X-linked mutations leading to PHK deficiency, known to exist in humans and mice, are likely to involve this locus. This hypothesis is consistent with the proximity of the Phk and Pgk-1 loci on the mouse X chromosome. In contrast, the beta subunit gene (PHKB) was found to be autosomal and was mapped to chromosome 16, region q12-q13 on the proximal long arm. Several different autosomally inherited forms of PHK deficiency for which the PHKB could be a candidate gene have been described in humans and rats.
