Prenatal diagnosis in a Chinese family with type Ia glycogen storage disease by PCR-based genetic analysis.
Type Ia glycogen storage disease (GSD), an autosomal recessive metabolic disorder, is caused by a deficiency in glucose-6-phosphatase (G6Pase). We had previously identified the nature of the causative mutations in a Chinese family whose first two children were affected with type Ia GSD. Two different point mutations in the G6Pase gene, a guanine to adenine substitution at base position 327 in exon 2 and a thymine to adenine substitution at base position 1101 in exon 5, change the restriction sites for the enzymes Fok I and Hinc II. Family study revealed that both parents were heterozygous carriers: the father with a mutant G6Pase allele at exon 2 and the mother with another mutant G6Pase allele at exon 5. This paper deals with a prenatal diagnosis on the fetus of this family who is at risk of type Ia GSD. Genomic DNA was extracted from a chorionic villus biopsy sampled at the tenth week of gestation. Exons 2 and 5 of the G6Pase gene were amplified by the polymerase chain reaction (PCR) followed by restriction enzyme digestion and direct sequence analysis. DNA analysis indicated that the fetus was a heterozygous carrier of type Ia GSD with a mutant G6Pase allele at exon 2 and a normal G6Pase allele at exon 5. The diagnosis was further confirmed by the same method with cultured amniocytes and with a blood sample after the baby was born. This is the first report of prenatal carrier detection of type Ia GSD at the gene level.
Lee
W J
WJ
Department of Medicine, Taichung Veterans General Hospital, Taiwan, R.O.C.
Yang
C H
CH
Ho
E S
ES
Shih
A
A
Lin
L Y
LY
Lin
W H
WH
D015193:Chorionic Villi Sampling; D004252:DNA Mutational Analysis; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005091:Exons; D005260:Female; D005952:Glucose-6-Phosphatase / Q000235:genetics; D005953:Glycogen Storage Disease Type I / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011296:Prenatal Diagnosis; D017422:Sequence Analysis, DNA; D013624:Taiwan
C035042:endodeoxyribonuclease FokI; D015252:Deoxyribonucleases, Type II Site-Specific; C024400:GTYRAC-specific type II deoxyribonucleases; D005952:Glucose-6-Phosphatase