Factor VIII (FVIII) gene mutations in 120 patients with hemophilia A: detection of 26 novel mutations and correlation with FVIII inhibitor development.
BACKGROUND
As the publication of the sequence of the factor VIII gene (FVIII) in 1984, a large number of mutations that cause hemophilia A (HA) have been identified. Thanks to the advances in the detection of mutations, it is now possible to identify a putative FVIII sequence alteration in the vast majority of patients with HA.


OBJECTIVE
Our main objective was to report on the spectrum of FVIII mutations and their distribution throughout the gene in 120 patients with HA.


METHODS
Screening of FVIII mutations was performed using direct sequencing. Newly described missense mutations were further studied by molecular modeling.


RESULTS
A total of 47 different HA causative FVIII mutations have been identified, 26 of which are described for the first time. These novel mutations include 14 missense and six nonsense mutations, two small deletions, one large deletion and three splice-site mutations. We further investigated the development of FVIII-specific inhibitors in all patients with HA. We found that four novel mutations (Ser882X, Tyr1786Ser, Ala2218Thr and a splice-site defect in intron 22) were associated with inhibitor development.


CONCLUSIONS
These data extend our insight into the mechanisms by which novel amino acid substitutions may lead to HA, and how HA patient genotypes influence the risk of FVIII inhibitor development.
Repessé
Y
Y
Laboratoire d'Hématologie, E.A. 3212, CHU de Caen, Caen, France. yohann.repesse@unicaen.fr
Slaoui
M
M
Ferrandiz
D
D
Gautier
P
P
Costa
C
C
Costa
J M
JM
Lavergne
J M
JM
Borel-Derlon
A
A
D019943:Amino Acid Substitution; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D005169:Factor VIII / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics*; D005838:Genotype; D006467:Hemophilia A / Q000097:blood* / Q000235:genetics*; D006801:Humans; D008297:Male; D008958:Models, Molecular; D009154:Mutation; D020125:Mutation, Missense; D017434:Protein Structure, Tertiary; D012307:Risk Factors; D017384:Sequence Deletion
D018389:Codon, Nonsense; D005169:Factor VIII