The replacement of cytogenetic analysis by direct chorionic villi sampling preparation with quantitative fluorescence PCR.

Aim: The aim of this study is to assess the replacement of chromosomal analysis of chorionic villi (CV) direct preparation samples (DIR) by quantitative fluorescence PCR (QF-PCR) and to determine its advantages in routine prenatal diagnosis.

Methods: From a total of 4,020 CV samples, rapid results were obtained either by conventional cytogenetic analysis of DIR in 2,770 samples, or by QF-PCR analysis in 1,250 samples. The final results were given after long-term culture (LTC).

Maternal uniparental isodisomy 20 in a foetus with trisomy 20 mosaicism: clinical, cytogenetic and molecular analysis.

The clinical significance of trisomy 20 mosaicism detected prenatally remains uncertain due to the rarity of liveborn cases with inconsistent clinical findings, and lack of long-term follow-up and outcome. We describe a case of true trisomy 20 mosaicism in a liveborn girl with maternal uniparental isodisomy of chromosome 20 in the diploid blood cells. Trisomy 20 mosaicism was originally detected in amniotic fluid (98%) and was confirmed in the term placenta (100%), as well as in the blood (10%) and urine sediment (100%) of the neonate.

Prenatal diagnosis of two rare de novo structural aberrations of the Y chromosome: cytogenetic and molecular analysis.

Two rare de novo structural aberrations of the Y chromosome were detected during routine prenatal diagnosis: a satellited non-fluorescent Y chromosome (Yqs), the first de novo Yqs to be reported in a fetus, and a terminal deletion of the Y chromosome long arm del(Y)(q11). In both cases detailed cytogenetic and molecular analyses were undertaken. In the case of the Yqs it was demonstrated by fluorescence in situ hybridization (FISH) that the satellites were derived from chromosome 15.