Mutations Causing Haemophilia B: Identification of a Rare Mutation in the EGF1 Domain of Coagulation Factor IX in Patients with Haemophilia B in the BATNA Region (Northeast Algeria)

Zidani Abla,Yahia Mouloud,Ouarhlent Yamina,Belhadi Kamilia

doi:10.21767/2393-8854.100023

Abstract

Haemophilia B (HB) (also known as Christmas disease) is a form of haemophilia characterized by a factor IX (FIX) deficiency leading to spontaneous or prolonged haemorrhage. It is inherited as x-linked recessive disorder which affects almost exclusively men. Depending on the nature of the genetic mutation that is the cause of the disease, the affected coagulation factor may be totally absent from the patient's organism or present but in a dysfunctional form. Different degrees of severity of haemophilia have been established: minor, moderate, severe, based on plasma anti-haemophilic factor activity. Generally, this circulating factor level correlates with observed clinical manifestations. Molecular studies of these mutations are essential to increase our understanding of their pathogenic effect causing the disorder. Nine male patients with severe HB, were enrolled in this study. DNA was extracted by the salting out method. Direct sequencing of a complete exon is possible once it has been amplified from genomic DNA with the polymerase chain reaction (PCR) technique. The HB mutation was identified by automated sequence analysis using the capillary electrophoresis method. We identified 2 point mutations (missense mutations). The first identified mutation is located in exon 4 and the second is situated in exon 8.

Highlights

Haemophilia is a recessive hereditary disease related to the X chromosome
It involves a decrease or even a total deficiency of FVIII or factor IX (FIX) of coagulation, which leads to a coagulation disorder
The FIX participates in an essential stage of haemostasis, its absence or its malfunctioning is at the origin of the formation of a clot of poor quality and the development of a haemorrhagic phenotype in the absence of adequate treatment

Summary

Introduction

Haemophilia is a recessive hereditary disease related to the X chromosome. It involves a decrease or even a total deficiency of FVIII (haemophilia A) or FIX (haemophilia B) of coagulation, which leads to a coagulation disorder.HB affects all populations on the planet with a prevalence of about 1 per 50,000 people. Haemophilia is a recessive hereditary disease related to the X chromosome. It involves a decrease or even a total deficiency of FVIII (haemophilia A) or FIX (haemophilia B) of coagulation, which leads to a coagulation disorder. HB affects all populations on the planet with a prevalence of about 1 per 50,000 people. It is about five times less common than haemophilia A. The FIX participates in an essential stage of haemostasis, its absence or its malfunctioning is at the origin of the formation of a clot of poor quality and the development of a haemorrhagic phenotype in the absence of adequate treatment. All localizations of the haemorrhagic syndrome are possible but the most frequently observed are located at the articular and muscular levels

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