We present our study on 318 patients suspected with Fanconi anemia (FA) referred to The Iranian Blood Transfusion Organization during the period of 4 years. Mitomycin C (MMC) was used as a DNA cross-linker to study chromosomal breakage. In total 61 positive cases were diagnosed cytogenetically. The ratio of women being affected was slightly higher than men. Comparison of several hematologic and clinical parameters in FA (MMC positive) and non-FA (MMC negative) patients showed no clinically significant differences. This study also indicates that this sort of test is very useful and essential for accurate diagnosis of patients with FA with or without congenital anomalies.

We conducted a cytogenetic study on 865 individuals with idiopathic mental retardation (MR) who were admitted to the Cytogenetics Department of the Iran Blood Transfusion Organisation (IBTO) Research Centre, Tehran, Iran; these were performed on blood samples using conventional staining methods. Chromosome anomalies were identified in 205 of the patients (23.6%). The majority were Down’s syndrome cases (n = 138). In 33 males, a positive fragile X anomaly was found. The remainder (n = 34) had other chromosomal abnormalities including structural chromosome aberrations (n = 23), marker chromosomes with an unknown origin (n = 3), sex chromosome aneuploidy (n = 6) and trisomy 18 (n = 2). The contribution of chromosome aberrations to the cause of MR in this group of patients is discussed.