Common mutation in the PHKA2 gene with variable phenotype in patients with liver phosphorylase b kinase deficiency

We found that the missense mutation p.Pro1205Leu in the PHKA2 gene is a common cause of hepatic phosphorylase-kinase deficiency in Dutch patients, suggesting a founder-effect. Most patients presented with isolated growth delay and diarrhea, prior to the occurrence of hepatomegaly, delaying diagnosis. Tetra-glucoside excretion correlated with disease severity and was used to follow compliance. The clinical presentation and therapeutic requirements in the same mutation carriers were variable, and PhK deficiency necessitated tube-feeding in some children. (C) 2011 Elsevier Inc. All rights reserved.