A very rare case report of glycogen storage disease type IXc with novel PHKG2 variants

Abstract

Background Pathogenic mutations in the PHKG2 are associated with a very rare disease—glycogen storage disease IXc (GSD-IXc)—and are characterized by severe liver disease. Case presentation Here, we report a patient with jaundice, hypoglycaemia, growth retardation, progressive increase in liver transaminase and prominent hepatomegaly from the neonatal period. Genetic testing revealed two novel, previously unreported PHKG2 mutations (F233S and R320DfsX5). Functional experiments indicated that both F223S and R320DfsX5 lead to a decrease in key phosphorylase b kinase enzyme activity. With raw cornstarch therapy, hypoglycaemia and lactic acidosis were ameliorated and serum aminotransferases decreased. Conclusion These findings expand the gene spectrum and contribute to the interpretation of clinical presentations of these two novel PHKG2 mutations.

Novel sequence of PHKG2 mutation associated with first case of glycogen storage disease type IXc in Syria: a case report

“…Laboratory tests are unhelpful because the changes are unspeci c and interfere with other hepatic and muscle types (13). Tests reveal fasting hypoglycemia, hepatic enzyme elevation, high serum transaminase, ketosis, cholestasis, increased Plasma cholesterol, triglycerides and total lipids with pathologic glucagon tolerance test (14,11,8,15). Normal uric acid levels, CPK and a slight elevation of plasma aminotransferases usually distinguish type IX from GSD type III (12,17 ).…”

“…Regarding treatment, most studies showed that uncooked cornstarch, low_ fat and high_ protein diet are the most helpful treatment for GSD IX patients (14).…”

Identification and validation of a five-gene prognostic signature based on bioinformatics analyses in breast cancer

“…Moreover, it encodes the hepatic isoform of the gamma unit of phosphorylase kinase. People get glycogen storage disease type IXc, a rare and severe phenotype of glycogen storage disease, when PHKG2 is defective [ 16 , 17 ]. The reported research showed that PHKG2 was frequent epigenetic hypermethylation in papillary thyroid cancer [ 18 ].…”