Molecular analysis of severe hemophilia B in Indian families: Identification of mutational hotspot and novel variants.

INTRODUCTION: Hemophilia B is associated with molecular heterogeneity, with more than 1200 unique variants in the F9 gene. We hereby describe the mutational spectrum of severe hemophilia B patients presenting in a tertiary-care center in India. METHOD: DNA was extracted from peripheral blood samples of 35 diagnosed severe hemophilia B patients belonging to 32 families, and were subjected to Sanger sequencing. Determination of the effect of novel variants on the protein structure and correlation between genotype and phenotype was attempted using in-silico tools. RESULTS: Twenty-seven different mutations were detected in 30 probands, including 20 known and 7 novel variants. Also, we found one suspected case of whole gene deletion. The serine peptidase domain harbored most of the variants (48.1%). Inhibitory antibodies were found in two patients. CONCLUSIONS: This study provides a comprehensive mutational spectrum and mutation screening strategy by Sanger sequencing of F9 gene in severe hemophilia B patients, in a resource-constraint setting.

A case of paraneoplastic hyperleukocytosis closely mimicking chronic neutrophilic leukemia.

Leukemoid reaction and myeloproliferative syndrome are close mimickers and frequently pose a diagnostic dilemma, particularly when the leukocyte count is very high. Leukocyte alkaline phosphatase score frequently aids in diagnosis but may or may not be contributory, especially in differentiating chronic neutrophilic leukemia. Herein, we document a case of leukemoid reaction with extensive hyperleukocytosis in a 46-year-old female with poorly differentiated carcinoma. The tumor itself as well as the associated leukocytosis portends a poor prognosis.