Glycogen phosphorylase kinase deficiency

MedGen UID:: 468559
•Concept ID:: C0268147
•: Disease or Syndrome

Synonyms:	Glycogen Storage Disease Type IX; Phosphorylase Kinase Deficiency
SNOMED CT:	Glycogen phosphorylase kinase deficiency (235908005); PHK - Hepatic phosphorylase kinase deficiency (235908005); Hepatic phosphorylase kinase deficiency (235908005); Phosphorylase kinase deficiency of liver (235908005); Glycogen storage disease type IX (235908005); Glycogenosis viiia (235908005)
Modes of inheritance:	Autosomal recessive inheritance MedGen UID: 141025 •Concept ID: C0441748 • Intellectual Product Source: Orphanet A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). X-linked recessive inheritance MedGen UID: 375779 •Concept ID: C1845977 • Finding Source: Orphanet A mode of inheritance that is observed for recessive traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked recessive disorders manifest in males (who have one copy of the X chromosome and are thus hemizygotes), but generally not in female heterozygotes who have one mutant and one normal allele. See: This record Autosomal recessive inheritance (Orphanet) X-linked recessive inheritance (Orphanet)

Related genes: Gene(s) associated with related conditions. For conditions in a hierarchy, the parent condition will list the genes associated with the children conditions.	PHKG2, PHKB, PHKA2, PHKA1

Orphanet:	ORPHA370

Disease characteristics

Excerpted from the GeneReview: Phosphorylase Kinase Deficiency

Phosphorylase kinase (PhK) deficiency causing glycogen storage disease type IX (GSD IX) results from deficiency of the enzyme phosphorylase b kinase, which has a major regulatory role in the breakdown of glycogen. The two types of PhK deficiency are liver PhK deficiency (characterized by early childhood onset of hepatomegaly and growth restriction, and often, but not always, fasting ketosis and hypoglycemia) and muscle PhK deficiency, which is considerably rarer (characterized by any of the following: exercise intolerance, myalgia, muscle cramps, myoglobinuria, and progressive muscle weakness). While symptoms and biochemical abnormalities of liver PhK deficiency were thought to improve with age, it is becoming evident that affected individuals need to be monitored for long-term complications such as liver fibrosis and cirrhosis. [from GeneReviews]