Unique glucose-6-phosphatase, catalytic subunit mutation in a child with type Ia glycogen storage disease in Taiwan

Abstract

The G272W mutation in the glucose-6-phosphatase, catalytic subunit (G6PC) gene has been reported once in mainland China, but has not been reported in Taiwan or other countries. We report a female patient with type Ia glycogen storage disease (GSD). She presented at birth with abdominal distension, shortness of breath, and nonbilious vomiting. Hyperammonemia, metabolic acidosis, hyperuricemia, and elevated liver function were noted after a subsequent survey. Tachypnea and metabolic acidosis were exacerbated whenever she was infected with croup. Abdominal and renal sonography performed at 2-year of age revealed marked hepatomegaly and nephromegaly, with increased echogenicity. The genetic survey of the patient demonstrated compound heterozygous mutations in the G6PC gene, including a codon 83 [c.248G >A, p.Arg83His] mutation inherited from her father, and codon 272 [c.814G >T, p.Gly272Trp] mutation inherited from her mother. Type Ia GSD was diagnosed based on the birth history, biochemistry, image study, and molecular diagnosis. After the girl was treated with cornstarch, her liver function and other abnormal biochemistry data gradually normalized. This report may facilitate clarifying the prognoses of Chinese patients with these 2 mutations of the G6PC gene. Furthermore, this report highlights the importance of the G272W mutation, which may be unique to the Chinese population.

Keywords

• Glycogen storage disease
• hyperammonemia
• hyperuricemia
• hepatomegaly
• nephromegaly