CONTEXT:Hemoglobinopathies constitute the world's most common genetically inherited red blood cell disorder. Screening and accurate identification of hemoglobin (Hb) variants have become increasingly important in antenatal diagnosis and prevention of Hb disorders.AIM:The aim of this study was to screen and identify Hb fractions prevalent in the Central Reference Laboratory of India.MATERIALS AND METHODS:A total of 65,779 cases were screened for hemoglobinopathies on the bio-rad variant high-performance liquid chromatography (HPLC) system by beta-thalassemia short program. The retention times, proportion of the hemoglobin (%) and the peak characteristics for all hemoglobin fractions were recorded. Molecular analysis of the beta-globin gene was carried out by DNA sequencing on eight cases.RESULTS:Total number of abnormal Hb fractions on cation exchange-HPLC (CE-HPLC) was seen in 12,131 (18.44%) cases. Beta-thalassemia trait was the predominant genetic Hb disorder accounting for 7377 cases (11.21%) of the total cases. This was followed by sickle cell trait (2.01%), sickle cell disease (1.59%), beta-thalassemia syndrome (0.80%), HbE trait (0.79%), and borderline HbA2 (0.51%). Molecular characterization of eight rare cases of hemoglobin variants by beta-globin gene sequencing identified three cases of Hb Beth Israel, two cases of Hb Hofu trait, and one case each of Hb J Cambridge, Hb Mizunami, and Hb Sherwood Forest.CONCLUSION:Superior resolution, rapid assay time, and accurate quantification make CE-HPLC suitable for the routine investigation of hemoglobinopathies.

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Notch-1 is a transmembrane receptor protein that directs T-cell differentiation. Gain-of-function mutations in Notch-1 have been reported in more than 50% of human T-cell acute lymphoblastic leukemia (T-ALL). The current study was undertaken to characterize mutations in the heterodimerization (HD) domain and proline, glutamic acid, serine, threonine-rich (PEST) domain of the Notch-1 receptor. RNA was isolated from peripheral blood/bone marrow of 15 de novo T-ALL subjects; the Notch-1 HD and PEST regions were amplified and sequenced. Overall six patients (40%) had at least one Notch-1 mutation, 2/15 (13%) in the HD and 4/15 (27%) in the PEST domain. None of the samples showed simultaneous mutations in HD and PEST domains. Mutations were seen in 4/10 adult patients (40%); in the pediatric cohort 2/5 (40%) had mutations both of which were in the PEST domain. Of the different mutations, two have been previously reported and the other four are novel. A high incidence of Notch-1 mutations has been seen; unlike other studies, a higher frequency of mutations was found in PEST domain. The current study also served to identify four novel mutants that add new insights into the genetic heterogeneity of T-ALL. More ongoing larger studies are warranted to elucidate the molecular pathogenesis of T-ALL that arises in this part of the world.

Our study on pan-Indian cases is one of the largest studies reported so far in India and focuses on the most accurate and comprehensive molecular diagnostic evaluation of HD.

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