Molecular pathology of haemophilia A in Indian patients: Identification of 11 novel mutations

BackgroundThe identification of pathogenic mutations in haemophilia A (HA) patients is important as a basis for genetic diagnosis and also for the assessment of clinical manifestations.MethodWe analyzed 36 inversion negative congenital HA cases (28 unrelated and 8 familial) by multiplex PCR and the conformation sensitive gel electrophoresis (CSGE) technique, followed by DNA sequencing. The pathogenicity of each of these mutations was assessed using various prediction software.ResultsWe found 17 missense, 5 deletions, 3 insertions, and 2 nonsense mutations, out of which 16 were recurrent and 11 novel. All novel substitution mutations were found to be deleterious using the prediction softwares. We also encountered a double mutation (1 novel and 1 hot-spot mutation) in a family with a strong family history. A missense mutation in heterozygous state was also detected in a female bleeder with very low factor VIII levels, probably due to extreme lyonization.ConclusionHigh heterogeneity in mutational profile has been observed in the present study. The outcome of this study would enable us to give an accurate diagnosis in all affected families by direct mutation analysis.