Genetic analysis in pregnancy with fetal pathologic ultrasound findings

In this study, we evaluated a total of 146 samples (79 Amniocentesis and 67Chordocentesis) out of 487 cases which were obtained from pregnant women withfetal pathological ultrasound findings. The samples were collected from patients whowere referred to the Genetic Diagnostic Laboratory of the Department of MedicalBiology, Medical Faculty, Dicle University, for prenatal diagnosis during January2007 to August 2008. A total of 341 samples (330 Amniocentesis and 11Chordocentesis ) were included in this study as controls. Control group samples weretaken from mothers without any pathological ultrasound findings.A total of 487 samples were analysed cytogenetically. Lymphocyte cultureprepared in duplicate and totally ten slides were prepared for each sample. One of theten slides was stained with direct Giemsa staining and the others were stained withGiemsa Banding Technique (GTG Banding). A total of 4870 (487x10) slides wereevaluated for diagnosis.A total of 146 samples were analysed in study group which has fetalpathologic ultrasound findings. Of the samples, 52 (35.6 %) had normal karyotypeof (46, XX), 51 (34.9 %) had normal karyotype of (46, XY) and 39 (26.8 %) werefound to have chromosomal abnormality. No result was obtained from 4 (2.7%)cases due to culture failure.Possible detection of chromosomal abnormality rate was calculated as 28.5 %for non immune hydrops fetalis, 10% for immune hydrops fetalis, 33 % forencephalocele, and 8.33 % for hyperechogenic intestine, 33 % for bilateralmulticystic kidney, 33 % for cardiac hyperechogenic focus, 31.25 % forventriculomegaly, 10 % for choroid plexus cyst, 38.44 % for cystic hygroma, 50 %short limbs, 33 % for gastroschisis, 50 % for nasal bone appearance, 16.6 % forspina bifida, 40 % for cardiac anomaly and 100 % for microcephaly.A total of 341 samples were analyzed in control group, and 147 (43.1 %)cases had 46 XX, 136 (39.9 %) cases had 46, XY normal karyotype. Of the cases, 49xi(14.4%) were detected to have abnormality, of which 24 cases were with high tripletest risk, 14 with high double test risk, 5 with advanced maternal age risk, 3 withfamilial disease history (46 Amniocentesis cases), and 2 with advanced maternalage and 1 with triple test risk (totally 3 Chordocentesis cases) were detected to haveabnormality. No results were obtained from 9 (2.6%) cases, 8 Amniocentesis and 1Chordocentesis due to culture failure.As indicated above the chromosomal aberration rate were found to be higherin study group (26.8%) when compared with control group (14.4%). Results wereevaluated with Student?s t test which compared to independent groubs rates forstatistical analysis. The result found significant (p<0.5)After evaluation of all 487 cases, indication rate were as follows; 36.8 % withhigh triple test risk, 30 % with pathologic ultrasound finding, 13.4 % with highdouble test risk, 12.5 % with advanced maternal age, 5.1 % with familial diseasehistory, 1.4 % with parental anxiety and 0.8 % with bad obstetric anamnesis.Chromosome aberrations were detected in 88 cases (18 %) No results was obtainedfrom totally 13 samples (9 Amniocentesis and 4 Chordocentesis) due to inconvenienttransportation condition of the samples, to our laboratory. Culture success rate of ourstudy has been calculated as 97.4 %. We have no false positive and false negativeresults in our study.The purpose of this study was to provide information on the degree andspecificity of association between prenatally diagnosed chromosome aberrations andpathological findings of detailed high resolution ultrasound imagining in fetuses.Also we evaluated whether or not these pathological ultrasound findings make anysense about the sort and frequency of chromosomal aberration and taken as criteria.The information that provided compared with the control group and discussedin the light of recent scientific knowledge.These findings are the results of our study involving limited number of cases.It is obvious that more extensive studies are required for generalization.KEY WORDS: Prenatal Diagnosis, Chromosome Analysis, ChromosomalAbnormality, Fetal Anomaly.