Genetic diagnosis in Hemophilia A from southern China: five novel mutations and one preimplantation genetic analysis

As there is currently no complete cure for hemophilia A (HA), the identification of pathogenic mutations in factor VIII (FVIII) gene from HA patients and carriers, which can contribute to genetic counseling prenatal diagnosis, and preimplantation genetic diagnosis (PGD), is an important step to prevent HA.A total of 14 unrelated Chinese HA subjects (FVIII activity <40%), 20 carrier subjects, three fetuses, and one PGD were included in this study. We first screened for the presence of FVIII intron 22 and intron 1 inversions. Second, the coding region of the FVIII gene was sequenced. For the novel mutations, FVIII mRNA expression was detected by real-time PCR and the protein structures were analyzed by bioinformatic tools.Five novel mutations (c.1A>C, c.304_305insA, c.1594T>A, c.6045G>A, and c.2645_2646insG) were found. The real-time PCR showed that the expression of FVIII mRNAs was lower in HA patients than in normal subjects. Prenatal diagnosis and PGD were successfully performed: Two of three fetuses and four of eight blastomeres were confirmed to be normal.In conclusion, genetic diagnosis of 14 unrelated HA subjects, 20 carrier subjects, three fetuses, and one PGD was successfully performed in our study.