A review of 1125 cases referred for cytogenetic analysis in Syria

Abstract

Introduction: The aim of this review is to evaluate the pattern of referral for cytogenetic analysis and to determine the frequency of chromosomal abnormalities in different groups of referrals, and then to compare these figures with similar studies. Patients and methods: This review included 1125 cases referred between 2007 and 2010 to the Cytogenetic Unit, Clinical Laboratories, Assad University Hospital in Damascus, Syria. The referrals fall under two categories: hematological disorders (HD) and constitutional chromosomal aberrations. Subjects and methods: All samples were subjected to standard cytogenetic procedures, followed by G-banding using trypsin and giemsa, and some were subjected to fluorescence in-situ hybridization according to the probe manufacturer’s protocol. Results and discussion: In HD group there were 847 samples. The chronic myelogenous leukemia group consisted of the largest number of referrals. The next subgroup in number of referrals was acute myelogenous leukemia. The myelodysplastic syndrome group came next, followed by acute lymphoblastic leukemia, and then chronic lymphocytic leukemia. Cytogenetic results were either recurring aberrations with important diagnostic significance (e.g. Philadelphia chromosome) or other aberrations with less clear significance. In the constitutional chromosomal aberrations group, 278 samples were analyzed. Significant statistical differences between the current study and other studies from Turkey, Saudi Arabia, and Jordan were seen in the referring frequencies. The Turner syndrome group had the highest frequency of referrals, followed by the reproductive problems group, which had abnormal results in frequencies similar to previous reports. The Down syndrome suspect group was next in the number of referrals, but it had the highest number of abnormal karyotypes. Then came the chromosomal syndrome suspect group, followed by the Klinefelter group, and the sex determination group with the lowest referral rates. Conclusion: This study highlights the importance of considering cytogenetic test during the management of HDs, and demonstrates the importance of incorporating it in evaluation plans for congenital abnormalities, sexual development problems, and reproductive problems.

Keywords: Constitutional Chromosomal Aberrations, Cytogenetics, Hematological Disorders, Karyotype, Syria