The association between sporadic somatic parental aneuploidy and chromosomally abnormal placentae in habitual abortions.

To determine whether there is a correlation between the proportion of aneuploid cells in peripheral lymphocytes and the karyotype of the abortus in recurrent miscarriage. 40 couples with recurrent miscarriage and their abortuses were cytogenetically analyzed according to the analysis of 60 cells per proband. Women were divided into two groups according to the proportion of chromosomally abnormal cells in the abortus. Chromosomal analysis was performed using G-banding with trypsin-Giemsa in parental peripheral blood and in the abortus. 20 of the 40 abortuses had a chromosomally abberant karyotype. 65% of parents aborting an embryo with with an increased proportion of chromosomally aberrant cells, had more than 10% aneuploid cells in their peripheral lymphocytes. However, only 12.5% of couples aborting an embryo with chromosomally normal cells had increased rates of aneuploidy. An increased proportion of aneuploid cells was found in the lymphocytes of recurrently aborting couples who repeatedly abort chromosomally abnormal fetuses. Mitotic instability in the lymphocytes may indicate a predisposition to instability at meiosis leading to a chromosomal abberations in the embryo and its subsequent abortion.

Prenatal diagnosis of Lesch-Nyhan syndrome: experience with three fetuses at risk.

Our experience with the prenatal detection of the Lesch-Nyhan syndrome (LNS; hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficiency) in three fetuses at risk is reported. Enzyme activities were measured in cultured amniocytes in two pregnancies, and in tissues and cultures obtained from chorionic villus sampling (CVS) in a third pregnancy. In all tissues the specific activities of HGPRT and adenine phosphoribosyltransferase (APRT) were determined and APRT/HGPRT ratios were calculated. In addition to the enzyme assays, the rate of purine synthesis de novo was assessed in the two amniocyte cultures, and the rate of [14C]hypoxanthine incorporation into nucleotides and sensitivity to azaguanine were measured in one of the amniocyte cultures. We report the diagnosis of normal fetuses by study of amniocytes in two pregnancies and of LNS using CVS in one pregnancy. In all three cases the diagnosis was confirmed.