Prenatal diagnosis with biotinylated chromosome specific probes

Area of Science:

• Genetics
• Prenatal Diagnostics
• Molecular Biology

Background:

• Accurate fetal sex determination and detection of numerical chromosomal abnormalities are crucial in prenatal diagnostics.
• Traditional cytogenetic methods can be time-consuming.
• Non-radioactive molecular techniques offer potential for faster and reliable prenatal analysis.

Purpose of the Study:

• To evaluate the efficacy of a Y-chromosome specific DNA probe for fluorescent hybridization in uncultured amniotic fluid cells.
• To determine the presence of Y-chromosome material and detect numerical abnormalities.
• To assess the reliability and speed of this non-radioactive method for prenatal genetic analysis.

Main Methods:

• Utilized a Y-chromosome specific DNA probe for fluorescent in situ hybridization (FISH).
• Applied the technique to uncultured amniotic fluid cells.
• Validated the method on cultured fetal fibroblasts and adult T-lymphocytes, as well as on aged cytogenetic preparations.

Main Results:

• Correctly predicted fetal sex in 51 out of 54 cases within 48 hours.
• Successfully identified one case of XYY syndrome.
• Demonstrated no false-positive or false-negative results in validation tests.
• Confirmed reliability of the technique on cytogenetic preparations up to 44 months old.

Conclusions:

• Fluorescent hybridization using a Y-chromosome specific DNA probe is a reliable and rapid method for fetal sex determination and detection of Y-chromosome related numerical abnormalities in uncultured amniotic fluid.
• This non-radioactive technique offers a significant advantage in prenatal diagnostics due to its speed and accuracy.
• The method's reliability extends to aged cytogenetic samples, broadening its potential applications.