Regional mapping of a liver alpha-subunit gene of phosphorylase kinase (PHKA) to the distal region of human chromosome Xp.
X-linked liver glycogenosis (XLG) is a glycogen storage disorder resulting from deficient activity of phosphorylase kinase (PHK). PHK consists of four different subunits: alpha, beta, gamma, and delta. Several genes encoding PHK subunits have been cloned and localized, but only the muscle alpha-subunit (PHKA) gene has been assigned to the X chromosome, in the region Xq12----q13. However, we have previously excluded the muscle PHKA gene as a candidate gene for the XLG mutation, as linkage analysis indicated that the mutation responsible for XLG is located in Xp22 and not in Xq12----q13. We report here the chromosomal localization by in situ hybridization of a liver PHKA gene to the distal region of chromosome Xp. Strong hybridization signals were observed on the distal part of the short arm of a chromosome identified as the X chromosome by cohybridization with an X chromosome-specific centromeric probe. The localization of this gene in the same chromosomal region as the disease gene responsible for XLG suggests that the liver PHKA gene is a highly likely candidate gene for the XLG mutation.
Wauters
J G
JG
Department of Medical Genetics, University of Antwerp-U.I.A., Belgium.
Bossuyt
P J
PJ
Davidson
J
J
Hendrickx
J
J
Kilimann
M W
MW
Willems
P J
PJ
D002874:Chromosome Mapping; D015342:DNA Probes; D005453:Fluorescence; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008856:Microscopy, Fluorescence; D009693:Nucleic Acid Hybridization; D010764:Phosphorylase Kinase / Q000235:genetics*; D014960:X Chromosome
D015342:DNA Probes; D010764:Phosphorylase Kinase