Cytogenetic results of amniocentesis materials: Incidence of abnormal karyotypes in the Turkish collaborative study


Karaoguz M. , Bal F., Yakut T., Ercelen N. O. , ERGÜN M. A. , Gokcen A. B. , ...More

GENETIC COUNSELING, vol.17, no.2, pp.219-230, 2006 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 17 Issue: 2
  • Publication Date: 2006
  • Title of Journal : GENETIC COUNSELING
  • Page Numbers: pp.219-230
  • Keywords: prenatal diagnosis, amniocentesis, indications, aberrations, aneuploidies, SERUM ALPHA-FETOPROTEIN, PRENATAL-DIAGNOSIS, GENETIC AMNIOCENTESIS, UNCONJUGATED ESTRIOL, CHROMOSOME ANALYSIS, DOWN-SYNDROME, NONDISJUNCTION, DISORDERS, CANADA

Abstract

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 I 1 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.