Abstract
A 31-year-old female was referred to our department because of gout. Physical examination was not contributory except for left ankle joint swelling. Laboratory data showed hyperuricemia, a high level of plasma oxypurines, increased urinary excretion of oxypurine and uric acid. Hypoxanthine-guanine phosphoribosyl transferase (HPRT) activity in erythrocytes was decreased, while PRPP synthetase activity was normal. The patient was diagnosed with a partial HPRT deficiency of the HRH type. The patient became pregnant during the analysis of HPRT activity. Genetic analysis of the patient’s HPRT was performed after gene counseling and the patient consented for ther analysis. The HPRT cDNA sequence revealed a point mutation of G to A in nucleotide 40, which changed codon 14 from GAA (Glu) to AAA (Lys) in the mutant gene. HPRT genomic DNA sequence demonstrated the same point mutation, indicating that the patient was heterozygote. Analysis of the AR gene on the X chromosome suggested nonrandom X-chromosome inactivation, whereas the AR XIST minimal promoter gene was normal. However, prenatal genetic analysis of HPRT was not performed based on the request of the patient and her husband and the pregnancy was continued. The patient gave birth to twin female babies uneventfully. The underlying problems of genetic and prenatal genetic diagnosis of pregnant women with a congenital genetic disorder are discussed.
