Feride İffet ŞAHİN, Vural DAĞLI, Ayla ÜÇKUYU, Ebru TARIM, Zerrin YILMAZ, Özge ÖZALP

Anöploidi taramasında konvensiyonel sitogenetik ve floresan in situ hibridizasyon bulgularının karşılaştırılması

Background and Aim: Prenatal diagnosis of chromosome abnormalities is usually performed on amniotic fluid samples. Aneuploidy screening by fluorescence in situ hybridization (FISH), although not an alternative for conventional cytogenetics, has become a useful tool. Materials and Methods: We compared the results of FISH and conventional cytogenetic analysis applied on 51 amniotic fluid samples between January 2002 and December 2005, in our Cytogenetics Laboratory. Amniocytes were extracted using 5 cc of the sample, and direct FISH was applied using an AneuVysion Assay Kit (Vysis). The remaining fluid samples were used for chromosome analysis by conventional methods after long-term cell cultures. Results: The results of both methods were compatible for 48 patients. For the 2 patients, although FISH results were normal, structural abnormalities were detected by the conventional cytogenetic method. In one patient, we detected mosaic trisomy 21 by FISH, whereas a 47,XX,+21 karyotype was identified in all cells that were examined by the conventional cytogenetic method. Conclusions: During genetic counseling, it is important to inform patients who undergo aneuploidy screening by FISH about the advantages and disadvantages of the method to help them acknowledge the results in the event that an abnormality is identified in the karyotype.

Comparison of conventional cytogenetic and fluorescence in situ hybridization resutls of prenatal aneuploidy screening

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1. McKinlay Gardner RJ, Sutherland GR. Chromosome Abnormalities Detected at Prenatal Diagnosis. in: Chromosome abnormalities and Genetic Counseling 3rd ed. New York: Oxford University Press; 2004; 392-432.
2. Verma RS, Babu A. Tissue Culture Techniques and Chromosome Preparation. In: Verma and Babu A, editors. Human chromosomes. 2nd ed. New York: McGraw-Hill Inc.; 1995; 6-71.
3. Schaffer LG, Tommerup N. An international system for human cytogenetic nomenclature ISCN, Karger, Switzerland, 2005.
4. Lim HJ, Kim YJ, Yang JH, Kim EJ, Choi JS, Jung SH et al. Amniotic fluid interphase fluorescence in situ hybridization (FISH) for detection of aneuploidy; experiences in 130 prenatal cases. J Korean Med Sci 2002; 17: 589-92.
5. Tepperberg J, Pettenati MJ, Rao PN, Lese CM, Rita D, Wyandt H et al. Prenatal diagnosis using interphase fluorescence in situ hybridization (FISH): 2-year multi-center retrospective study and review of the literature. Prenat Diagn 2001; 21: 293-301.
6. Pergament E, Chen PX, Thangavelu M, Fiddler M. The clinical application of interphase FISH in prenatal diagnosis. Prenat Diagn 2000; 20: 215-20.
7. Nicolaides HK. First-trimester screening for chromosomal abnormalities. Semin Perinatol 2005; 29: 190-194.
8. Benn PA, Gainey A, Ingardia CJ, Rodis JF, Egan JFX. Second trimester maternal serum analytes in triploid pregnancies: correlation with phenotype and sex chromosome complement. Prenat Diagn 2001; 21: 680-686.
9. Perenc M, Dudarewicz L, Kaluzewski B. Utility of the triple test in the detection of abnormalities of the feto-placental unit. Med Sci Monit 2000; 6: 994-999.
10. Meier C, Huang T, Wyatt PR, Summers AM. Accuracy of trisomy 18 screening using the second-trimester triple test. Prenat Diagn 2003; 23: 443-446.
11. Shipp TD, Benacerraf BR. Second trimester ultrasound screening for chromosomal abnormalities. Prenat Diagn 2002; 22: 296-307.
12. Feldman B, Ebrahim SA, Hazan SL, Gyi K, Johnson MP, Johnson A et al. Routine prenatal diagnosis of aneuploidy by FISH studies in high-risk pregnancies. Am J Med Genet 2000; 90: 233-238.
13. D'Alton ME, Malone FD, Chelmow D, Ward BE, Bianchi DW. Defining the role of fluorescence in situ hybridization on uncultured amniocytes for prenatal diagnosis of aneuploidies. Am J Obstet Gynecol 1997; 176: 769-74.