Affiliations: Department of Human Genetics, Institute of Genetic Medicine and Genomic Science, Kolkata, West Bengal, India | Department of Genetics, Institute of Genetic Engineering, Kolkata, West Bengal, India
Note:  Corresponding author: Amit Chakravarty, MD, Department of Human Genetics, Institute of Genetic Medicine and Genomic Science, 30A Thakurhat Road, Kolkata-700128, West Bengal, India. Tel.: +91 9831095960, +91 33 2526 0051/52/53; Fax: +91 33 2526 0060; E-mail: [email protected]
Abstract: Here, we present two thalassemic patients (one male and one female), having unusual clinical phenotypes. Both had mental retardation in which one was associated with microcephaly and other had congenital cataract. They were referred to our institute for clinical evaluation and cytogenetic testing. Both patients were tested for presence of abnormal hemoglobin by high performance liquid chromatography and found to be thalassemic. Their β-globin mutation was also determined by amplification refractory mutation system-polymerase chain reaction. The male patient was found to have intervening sequence 1-5 (G-C)/+, indicating β-thalassemia trait and the female was found to have Cod 26 (G-A)/IVS 1-5 (G-C), indicating hemoglobin E-β thalassemia. Their cytogenetic analysis of blood lymphocytes were studied with high-resolution GTG-banding analysis by using chromosome profiling (Cyto-vision software 3.6) on their chromosomes. Results revealed 46,XY,del(1)(p36.21) in the male and 46,XX,del(1)(p36.3) in the female. Their genotype variation showed (based on genome browser) significant gene loss which probably leads to marked phenotype variation. We believe, thalassemia with mental retardation associated with microcephaly and congenital cataract, both having loss in chromosome 1, p36 position, is reported probably first time from India. This report will definitely enlighten all concerns and add to the information in growing literature.