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

► The PHKA2 mutation p.Pro1205Leu is common in Dutch patients; Early diarrhea and growth delay might appear before hepatomegaly. ► Significantly elevated liver transaminase and lactate levels occur frequently. ► Some patients with hypoglycemia require tube feeding. ► Urine tetraglucoside excretion in sensitive for diagnostics and treatment follow-up.