Background: Hemophilia-A, a X-linked congenital bleeding disorder with an approximate frequency of 1 in 10000 males, is caused by a deficiency in factor VIII (FVIII). The FVIII gene is located on the long arm of the X chromosome at Xq28, spans 186 kb, and consists of 26 exons. In this research, we report a new mutation in FVIII gene in Hemophilia a patient referring to Tabriz children’s hospital in 1385.

Case Report: The patient was a 6-year old boy (HA10) referred to Tabriz children hospital in 1385 due to gum bleeding. Severe bleeding, low rate of FVIII and medical inspections showed probability of severe hemophilia A. So, to detect causal mutation, in this research we used PCR-SSCP method.

Results: A novel missense mutation in exon 4 of FVIII gene was detected that had not been reported in the list of FVIII gene mutations. The novel mutation is due to T → C transition at codon 153 (TGC) of the factor VIII gene, which replaces a cysteine with an arginine residue. This mutation was recorded in GenBank with accession number EF581382.

Conclusion: In this research it was observed that a point mutation in FVIII gene can be a cause of severe hemophilia A. So, this study shows that the methodology of PCR-SSCP may be useful in detecting most of the genetic defects of hemophilic patients. Also, disease screening and genetic consulting before marriage are necessary to inhibit the birth of affected children.