Cytogenetic results of amniocentesis materials: incidence of abnormal karyotypes in the Turkish collaborative study.
The experience on prenatal chromosome diagnosis of four Turkish centers participating in a collaborative study on 6041 genetic amniocentesis performed during a 4-8 years period were reviewed. 5887 (97.5%) patients had strong clinical indications for prenatal chromosome studies and 154 (2.5%) were referred because of maternal anxiety and a bad history of previous gestations. The main indication groups were: advanced maternal age (3197 cases), positive serum screening (2011 cases), ultrasound-identified anomaly (492 cases), previous fetus/child with chromosomal aberrations (103 cases), a history of a previous abnormal and/or mentally handicapped child (70 cases) and a parental chromosome rearrangement (14 cases). The average maternal age was 33.9 years and average gestational age was 18 weeks. A total of 179 affected fetuses were detected in this collaborative study (3%) of which 133 were unbalanced (74.3%). Among the 124 (69%) numerical aberrations, 102 (82.3%) were autosomal aneuploidies, 20 (16.1%) were gonosomal aneuploidies and 2 (1.6%) were poliploidies. Among the 55 (31%) structural aberrations, balanced translocation was the most common (63.6%) and 11 cases of inversion, four cases of unbalanced translocation, two cases of marker chromosome and three cases of other abnormalities were found. The overall culture success rate was 99.7%. Pregnancy termination that is permitted by legal authorities was accepted by 94.7% (126/133) with parents at unbalanced cytogenetic result announcement.
Karaoguz
M Yirmibes
MY
Department of Medical Genetics, Gazi University Faculty of Medicine, Ankara, Turkey. karaoguz@gazi.edu.tr
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Yakut
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Ercelen
N Ozturk
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Ergun
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Gokcen
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Biri
A Asyali
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Kimya
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Urman
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Gultomruk
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Egeli
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Menevse
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D000293:Adolescent; D000328:Adult; D000649:Amniocentesis / Q000379:methods* / Q000706:statistics & numerical data; D000782:Aneuploidy; D002391:Catchment Area, Health; D002869:Chromosome Aberrations; D003582:Cytogenetics / Q000379:methods*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000453:epidemiology; D015870:Gene Expression / Q000235:genetics; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D008875:Middle Aged; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012307:Risk Factors; D020858:Tissue and Organ Harvesting; D014314:Trisomy / Q000175:diagnosis / Q000235:genetics; D014421:Turkey / Q000453:epidemiology