[Prenatal diagnosis of Lesch-Nyhan syndrome]

A pregnant woman with Lesch-Nyhan's syndrome (hypoxanthine-guanine-phosphoribosyltransferase, or HGPRT deficiency) requested antenatal diagnosis. HGPRT and adenine phosphoribosyltransferase (APRT) activities were measured in fetal erythrocytes by funiculocentesis in the 21st gestational week. HGPRT activity was lower than 0.01 mmol/h/Hb g (normal value 87.0 +/- 16.05 mmol/h/Hb g). APRT activity was increased (44.0 mmol/h/Hb g) as compared with that from 50 normal individuals (28.1 +/- 6.9 mmol/h/Hb g). Pregnancy was interrupted and the antenatal diagnosis of Lesch-Nyhan's syndrome was confirmed after delivery. In the 20th gestational week, amniotic fluid showed a marked increase if oxypurines (hypoxanthine, xanthine and uric acid) as compared with the values in 14 amniotic fluids from normal pregnancies and gestational age within 15-22 weeks. The present study illustrates the possibility to make the antenatal diagnosis of Lesch-Nyhan's syndrome by funiculocentesis . The previously unreported finding of a marked abnormality of oxypurine concentration in amniotic fluid represents a new outlook for the diagnosis of enzymatic defects of synthesis and degradation of purine nucleotides.