Prenatal sexing and sex determination in infants with ambiguous genitalia by polymerase chain reaction.

Sex determination in both fetuses and infants with ambiguous external genitalia usually necessitates time-consuming and costly karyotyping. We propose a simple, rapid, and reliable method of prenatal and postnatal sex determination by means of the PCR, a technique currently used to identify gender for forensic purposes. DNA was extracted from 20 samples of whole blood from infants with ambiguous genitalia and from five samples of amniotic fluid. Three markers were amplified from each specimen: a Y chromosome alphoid repeat sequence and two homologous genes, amelogenin (AME) and zinc finger protein (ZFP). All three were detected in under 10 hr. A comparison of the results obtained with those of cytogenetic analysis of the same samples showed a perfect sex match, demonstrating that this PCR technique provides an accurate means of determining gender.

Type distribution and allele frequencies of three serum proteins in the Asiago Plateau population (northern Italy).

Historical studies on the Asiago Plateau have pointed to the peculiarity of its inhabitants in terms of their socio-cultural development marked by long periods of linguistic and cultural isolation. The present research on some serum protein markers (TF, GC and HP) aims to establish whether this isolation may have caused this population to become different from the others in terms of gene frequencies. For this purpose, transferrin (TF), group-specific component (GC) and human haptoglobin (HP) polymorphisms were studied in 435 subjects. GC and HP were found to be within the range of variation known for the Italian Peninsula.

Genetic polymorphism of C3 in the Veneto population, Italy.

The distribution of C3 phenotypes in the population of Veneto was investigated by electrophoresis on agarose gel. In our sample (n = 810) the three common phenotypes C3 SS, C3 FF and C3 FS and a further phenotype, C3 S-VF, were observed. The following gene frequencies could be calculated: C3S = 0.8068, C3F = 0.1926 and C3V = 0.0006. These frequencies have been compared with those found in other populations. The analysis of 21 mother-child pairs was in agreement with an autosomal codominant inheritance.

The distribution of some polymorphisms in Italy.

A wide data collection on blood group gene frequencies in Italian regions and provinces is presented. This report is the result of a joint collaboration of human geneticists and forensic haematologists started in 1979 and updates a previous work by the same group. The following genetic polymorphisms have been examined: red-cell antigens (ABO, FY, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus), red-cell enzymes (ACP1, ADA, AK1, ESD, GLO1, GPT, PGD, PGM1), plasma proteins (BF, C3, GC, HP, IGK, PI, TF). Data have been classified according to genetic systems, Italian regions and provinces. Gene frequencies were estimated by the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions has been evaluated by the likelihood ratio statistics. Genetic heterogeneity of provinces and regions is reported.