Journal of Blood Disorders & Transfusion

Haemophilia a carrier detection among Sudanese families: DNA linkage analysis approaches

16^th World Hematology Congress

March 18-19, 2019 | Rome, Italy

Rayan Elsheikh and Eltaher Khalil

University of Khartoum, Sudan

Posters & Accepted Abstracts: Blood Disord Transfus

Abstract:

Haemophilia A is the most common X-linked inherited bleeding disorder caused by a deficiency in the activity of coagulation factor VIII, with an incidence of 1 in 5000 male births. Genetic diagnosis of haemophilia A is the most accurate method available for carrier detection. Direct mutation detection for haemophilia A is difficult and expensive. Accordingly, genetic testing for carrier detection has relied upon indirect linkage studies employing polymorphic markers of factor VIII locus. The study was aimed to investigate the usefulness of three intragenic DNA markers located in intron 18 [BclI restriction fragment length polymorphism (RFLP)], intron 13 and intron 22 CA repeats linkage analysis for carrier detection in Sudanese families. This was a prospective, cross sectional, analytical and community based study. Following written informed consent 20 families with atleast one subject affected with haemophilia A and 30 unrelated normal females as control group were enrolled. Polymerase chain reaction (PCR) and restriction enzyme analysis were used to study the polymorphism in BclI. Intron 13 and intron 22 CA repeats were analyzed using fluorescent PCR followed by capillary electrophoresis. The incidence of BclI (+) allele was 78%, 39.5% and 33% in patients, female relatives and control group respectively. Expected heterozygosity for BclI was 0.48 in female relatives compared with 0.46 in the female control group. However, observed heterozygosity was found to be 0.54 in female relatives compared to 0.66 in the control group. The defective X chromosome was tracked in 13/20 (65%) mothers, hence 65% of the studied families were found to be informative using BclI-RFLP. Intron 13CA repeats were studied in 9 families. The defective X chromosome could be tracked down in 4/9 (44.4%) mothers. Intron 22 CA repeats were studied in 11 families and all families were uninformative. PCR-RFLP using BclI is informative in carrier detection of Haemophilia A in the Sudanese population. BclI is more informative compared to both Introns 13 and Intron 22 CA repeats BclI.

Biography :

E-mail: rayan.elsheikh@hotmail.com