Glucose-6-phosphatase gene mutations in Taiwan Chinese patients with glycogen storage disease type Ia.

Glycogen storage disease type Ia (GSD Ia) is caused by a deficiency of glucose-6-phosphatase (G6Pase) activity. Eighteen GSD Ia families were studied for G6Pase gene mutations. Thirty-two mutations were found in 36 GSD Ia chromosomes: 16 were 727 G-->T (44.44%); 13 were R83H (327 G-->T; 36.11%); 1 was 341delG; 1 was 933insAA; and 1 was 793 G-->T. The 727 G-->T and R83H mutations together accounted for 80.56% (29/36) of the GSD Ia chromosomes. These two mutations were easily examined by polymerase chain reaction-based methods, and the prenatal diagnosis of a non-affected fetus was successfully made. The 727 G-->T mutation is the predominant mutation in Japanese GSD Ia patients, but is rarely seen in Western counties. The 727 G-->T mutation is also the most prevalent mutation in Taiwan Chinese, although the incidence is not as high as in Japan.