Introduction of the QF-PCR analysis for the purposes of prenatal diagnosis in Bulgaria--estimation of applicability of 6 STR markers on chromosomes 21 and 18.
OBJECTIVE
The aim of our study was to estimate the observed heterozygosity and informativeness of 6 STR markers on chromosomes 18 and 21 in the Bulgarian population. We have evaluated the applicability of these markers used from other investigators for QF-PCR prenatal diagnosis of the most common autosomal aneuploidies in Bulgaria.


METHODS
DNA samples (n = 486) were extracted from different fetal tissues (amniotic fluid cells, chorionic villus samples, and fetal tissue after abortions). PCR amplifications of 4 STR markers located on chromosome 21 (D21S11, D21S1411, D21S1270, and D21S1440) and 2 on chromosome 18 (D18S535 and D18S51) were performed. They were analysed on an automated sequencer, and the allele dosage ratios were calculated.


RESULTS
The results indicate the selected markers as highly informative for our population and suitable for QF-PCR prenatal diagnosis in Bulgaria. All samples with trisomy 21 (n = 8), trisomy 18 (n = 4) and triploidy (n = 1) were correctly detected by our analysis. Thus, no false-negative results were observed.


CONCLUSIONS
QF-PCR analysis could be an applicable alternative in prenatal and postnatal diagnosis in cases with a strong suspicion for particular autosomal aneuploidies (including chromosomes 21, 18, and 13) in small countries with limited resources like Bulgaria.
Andonova
Silvia
S
Laboratory of Molecular Pathology, Hospital of Obstetrics and Gynecology, Medical University, Sofia, Bulgaria. sandonova@netscape.net
Vazharova
Radoslava
R
Dimitrova
Violeta
V
Mazneikova
Valentina
V
Toncheva
Draga
D
Kremensky
Ivo
I
D000782:Aneuploidy; D002031:Bulgaria; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics; D002887:Chromosomes, Human, Pair 18; D002891:Chromosomes, Human, Pair 21; D004247:DNA / Q000032:analysis*; D004586:Electrophoresis; D005260:Female; D005453:Fluorescence; D005819:Genetic Markers; D005865:Gestational Age; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D014314:Trisomy / Q000175:diagnosis
D005819:Genetic Markers; D004247:DNA