Rapid detection of autosomal aneuploidy using microsatellite markers
- Hospital for Sick Children, Ontario (Canada)
- Toronto Hospital, Ontario (Canada); and others
Trisomy occurs in at least 4% of all clinically recognized pregnancies, making it the most common type of chromosome abnormality in humans. The most commonly occurring trisomies are those of chromosomes 13, 18, 21 and aneuploidy of X and Y, accounting for about 0.3% of all newborns and a much higher percentage of conceptuses. In Canada, prenatal chromosome analysis by amniocentesis is offered to those women {ge} 35 years of age at the time of delivery or equivalent risk by maternal serum screen. We are developing a rapid molecular diagnostic test to detect the most common autosomal aneuploidies in prenatal and neonatal samples. The tests makes use of highly polymorphic short tandem repeat markers labeled with fluorescent tags which allow analysis on a GENESCANNER automated fragment analyzer (ABI). Multiple polymorphic markers have been selected on each of chromosomes 13, 18 and 21. At a given locus, trisomic fetuses/neonates will have either three alleles or two alleles with one allele having twice the intensity of the other. Unaffected individuals have two equal intensity alleles. We are conducting a blind study that will compare the detection efficiencies of FISH analysis on uncultured cells and the molecular method on confirmation amniotic fluid samples collected at the time of termination of affected fetuses. Results on cultured amniocytes from one such patient confirmed that trisomy 21 can be detected. FISH was not done on this sample. In addition, detection efficiency of the molecular method in whole blood samples from affected neonates is also being studied. To date, two such samples have been tested, one with trisomy 13 and one with trisomy 18, and both samples were diagnosed correctly. Preliminary results suggest that this method may provide a valuable tool for the rapid diagnosis of aneuploidy.
- OSTI ID:
- 134504
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-1238
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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