Glycogen storage disease type VI

The Crohn's Hers, (Eng. Hers disease), glycogen storage disease type VI, belongs to the group of glycogen and is an autosomal recessive, respectively, X-linked metabolic disorder. Cause various defects in the enzyme phosphorylase / kinase system, the liver and muscles. Known are the X- chromosomal defect in the phosphorylase b kinase of the liver, the defect of Leberphosphorylase (autosomal recessive ) and the combined loss of phosphorylase b kinase in the liver and muscles ( autosomal recessive). For Leberphosphorylase mutations PYGL gene could be identified with the gene locus on chromosome 14q21 - q22. For the combined liver and muscle phosphorylase deficiency PHKB the gene ( 16q12 - q13 ) has been described and, finally, for the X- chromosomal inheritance of liver phosphorylase kinase the PHKA2 gene ( Xp22.2 - p22.1 ). Disorders of phosphorylase / kinase system occur also in the glycogen storage diseases type VII, IX and X.

The disease is named after Henri- Gery Hers.

Clinical examination and follow

The disease, which manifests itself consistently in childhood is characterized by a bland history. Symptom are the hepatomegaly and growth retardation. Mild to moderate hypoglycemia may occur, but are formed as well as hepatomegaly in age back. For some de novo mutations (eg G233D ) residual enzyme activity could be detected, with milder ketosis, low elevated transaminases, cholesterol, and triglycerides. In the case of X-linked defect of liver phosphorylase kinase was in rare cases of splenomegaly, liver cirrhosis, osteoporosis, neurological disorders, elevated lactate levels with metabolic acidosis, renal tubular acidosis, stem accented obesity and a " doll face " reports.

Diagnosis

The detection of reduced enzyme activity in the liver ( phosphorylase ) and in leukocytes and erythrocytes ( kinases ) or the molecular genetic evidence of a genetic mutation confirm the diagnosis in conjunction with the clinical findings.

Therapy

In the majority of patients with glycogen storage disease type VI purely symptomatic treatment with prevention of hypoglycemic phases in overall good prognosis of the disease is sufficient. In more severe cases, the corresponding metabolic disorders have balanced and organ dysfunction are compensated.