Prevalence of Pericentric Inversion of Chromosome 9 in Eastern Anatolia Region and Relationship to Reproductive Efciency EJ M O Address for correspondence: Sengul Yuksel, MD. Inonu Universitesi Tip Fakultesi Tibbi Biyoloji ve Genetik Anabilim Dali, Malatya, Turkey Phone: +90 422 341 06 60 - 12 48 E-mail: sengul.yuksel@inonu.edu.tr Submitted Date: November 01, 2017 Accepted Date: November 20, 2017 Available Online Date: December 07, 2017 © Copyright 2018 by Eurasian Journal of Medicine and Oncology - Available online at www.ejmo.org T he frequency of human chromosome anomalies (nu- merical or structural) is reported to be 7.5% in the gen- eral population. [1] In humans, chromosomal anomaly, such as pericentric inversion, is observed in all chromosomes, ex- cept chromosome 20. In many cases, phenotypic anomaly is not observed as a result of inversions in heterochromatin areas, such as 1qh, 9qh, 16qh, and this condition is called polymorphism. [2] Pericentric inversion of chromosome 9 is considered as one of the most prevalent variations of the human karyotype. [3] Inversion of chromosome 9 is fre- quently found in normal individuals, and its frequency in the general population is expected to be approximately 1%–3%. [1] Since the clinical signifcance of inv (9) was de- fned in 1972, it has become a matter of debate. For in- stance, the last version of International System for Cytoge- netic Nomenclature (ISCN) mentioned inv (9) (p12q13) as a chromosome polymorphism without clinical signifcance. However, several authors supported possible correlation between inv (9) and certain clinical diagnoses similar to congenital anomalies, such as schizophrenia, increased Objectives: One of the most common, structurally balanced chromosome rearrangements is the pericentric inversion of chromosome (inv[9]). It is considered to be a variant of the normal karyotype, and has been found in both normal populations and patients with various abnormal phenotypes. The aim of this study was to determine the frequency of chromosome 9 rearrangement in the Malatya Province and check whether it is correlated with certain diseases. Methods: In this study, we investigated the karyotype analysis of 4168 patients admitted in the Turgut Özal Medical Center and Research Hospital, Genetic Disease Diagnosis Center Laboratory, between 2014 and 2016 and retrospec- tively reviewed their clinical data. Chromosomes from cultured peripheral blood lymphocytes were analyzed using Giemsa Trypsin-Giemsa (GTG) banding. Results: Pericentric inversion was detected in 71 (1.7 %) of 4168 cases, including 32 (45.1%) cases with inv(9) causing infertilty, 21 (29.6%) causing growth retardation, four (5.6%) causing multiple spontaneous abortion, and 14 (19.7%) causing other abnormalities, all of which were referred to our laboratory. Conclusion: In this study, the distribution of inv (9) in the Malatya Province was shown, and it is believed that these results would contribute to the knowledge regarding the incidence of inv (9) in the Eastern Anatolia Region and Turkey. Keywords: Inversion 9, karyotyping, Malatya, polymorphism Sengul Yuksel, Serap Savaci, Cemal Ekici, Elcin Latife Kurtoglu, Selcen Korkmaz, Elif Yesilada Department of Medical Biology and Genetics, Inonu University Faculty of Medicine, Malatya, Turkey Abstract DOI: 10.14744/ejmo.2017.06978 EJMO 2018;2(1):40-42 Research Article