Screening of mutations of hemophilia A in 40 Italian patients: a novel G-to-A mutation in intron 10 of the F8 gene as a putative cause of mild hemophilia A in southern Italy.
Hemophilia A is an X-linked bleeding disorder caused by widespread mutations in the human coagulation factor 8 gene. We have searched for mutations in factor 8 gene DNAs from 40 unrelated Italian patients with hemophilia A. All patients came from the same region (Calabria) and were followed-up at the same hemophilia center. Of the 40 patients, 20 (50%) had severe hemophilia A, 19 (47.5%) had moderate hemophilia A, and one (2.5%) had mild hemophilia A. All patients were first screened for the common intron 22 and intron 1 inversions. Inversion-negative samples were screened for point mutations by direct sequencing of all coding regions and intron-exon boundaries of the factor 8 gene. Mutations previously reported as causative of hemophilia A were identified in 14 of the 40 patients. These included five (12.5%) intron 22 inversions, one (2.5%) small deletion, one (2.5%) small insertion and seven (17.5%) point mutations. In all patients with moderate and mild hemophilia A, a nucleotide change in the c.1538 -18G>A in intron 10, not reported in the HAMSTeRS factor 8 mutation database (http://europium.csc.mrc.ac.uk/), was found. The G-to-A change predicts the appearance of a new acceptor splice site. We have also demonstrated that all patients share a common haplotype, suggesting that the mutation probably occurred in a single ancestor. In conclusion, we suggest that the c.1538-18G>A transition can be the putative mutation, which probably occurred in a common ancestor and then spread in neighbours, in patients with moderate-mild hemophilia A investigated in the present study.
Santacroce
Rosa
R
Istituto di Genetica Medica, Dipartimento di Scienze Biomediche, Università degli Studi di Foggia, Italy. rossa_na@hotmail.com
Santoro
Rita
R
Sessa
Francesco
F
Iannaccaro
Piergiorgio
P
Sarno
Michelina
M
Longo
Vittoria
V
Gallone
Anna
A
Vecchione
Gennaro
G
Muleo
Gaetano
G
Margaglione
Maurizio
M
D004252:DNA Mutational Analysis; D005169:Factor VIII / Q000235:genetics*; D018703:Founder Effect; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D006467:Hemophilia A / Q000235:genetics* / Q000503:physiopathology; D006801:Humans; D007558:Italy; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
D005169:Factor VIII