TY - JOUR T1 - Prevalence of Chromosomal Abnormalities in Patients with Consanguineous Marriages Referred to Sarem Women’s Hospital, Tehran, Iran TT - شیوع ناهنجاری‌های کروموزومی در بیماران با ازدواجهای خویشاوندی ارجاع شده به بیمارستان زنان و زایمان صارم JF - saremjm JO - saremjm VL - 6 IS - 2 UR - http://saremjrm.com/article-1-218-en.html Y1 - 2021 SP - 85 EP - 93 KW - Consanguineous Marriage KW - Genetics Counseling KW - Chromosomal Abnormality KW - GTG-Banding KW - Recurrent Abortions KW - Infertility N2 - Background and Objective: Consanguinity is defined as the marriage between close relatives. The deleterious effects associated with consanguinity may be caused by the expression of rare recessive genes inherited from common ancestors. Consanguineous marriage is significantly higher in many genetic diseases leading to prenatal, neonatal, child morbidity or mortality. Consanguineous marriage is a common practice in the Middle East including Iran with a rate of 30-85%. The present study was undertaken to analyze the prevalence of chromosomal abnormality (CA) in patients with consanguineous marriages. Material & Methods: Standard Cytogenetics techniques were carried out on the peripheral blood of 1055 patients with consanguineous marriage. Chromosome analysis was carried out using GTG-banding technique. The patients were referred to the Cytogenetics laboratory of Sarem Women's hospital during 2006-2021. 969 patients were due to genetic counseling for consanguineous marriage and 86 patients with a referral of consanguineous marriage and other reasons comprising of the previous history of recurrent abortions, infertility, intellectual disability, expired child, stillbirth, and a child with chromosome abnormality. Findings: Chromosomal abnormalities were found in 34 patients (3.22%) out of a total of 1055 patients. Most of the abnormalities were structural (97 %). Chromosomal abnormalities were found in 15 females (44.1%) and 19 males (55.9%). Inversions were the most common chromosomal abnormalities (64.7 %) diagnosed in this study. Pericentric inversion around the centromere of chromosome 9 was observed in 18 cases (1.70 %). Chromosomal inversions were found in the heterochromatin region of chromosome 1 in one case and chromosome 2 in one other case. Paracentric inversion of chromosome 14 was found in one case. One patient had a pericentric inversion of large size in one chromosome 9. Robertsonian translocation was found in three patients. Five patients had reciprocal translocation between two chromosomes. One patient had insertion of an unknown chromosome material within the short arm of chromosome 3. Amongst patients with consanguineous marriage and other reasons, only those with recurrent abortions (3 abnormals) and infertility (1 abnormal) had chromosome abnormalities. Chromosome abnormality rate in individuals referred for consanguineous marriage genetic counseling was 3.09% compared to 4.65% in those referred for consanguineous marriage and recurrent abortions or infertility. Conclusion: Compared to the rate of chromosome abnormality in the general population of less than 1%, the 3.09% of chromosomal abnormalities rate in consanguineous marriages in this study is high. However, this rate is even higher in individuals with consanguineous marriage and a history of recurrent abortion or infertility, with 4.65%. Due to the high rate of consanguineous marriages in the Iranian population, genetic counseling and chromosome analysis in couples with consanguineous marriage is highly recommended. M3 10.52547/sjrm.6.2.85 ER -