Molecular biology and clinical manifestation of hereditary factor VII deficiency.

ABSTRACT

Inherited factor VII (FVII) deficiency is a rare autosomal recessive disorder. Mutations and polymorphisms of the FVII gene were characterized in more than 40 unrelated patients with FVII deficiency. Among the 29 different mutations, the most frequent were Ala294 Val, Ala294Val;404delC, IVS7+7, and Val281 Phe. Four novel mutations (IVS2+1G>C, Arg247 Cys, Glu265 Lys, Asp343 His) were detected. The relationships between genotypes of mutations and polymorphisms of the FVII gene, FVII deficiency, and clinical phenotype were investigated. Homozygosity of the Phe4 Leu, IVS4+1G>A, Cys135 Arg, Ala244 Val, and Ala294 Val;404delC and the double heterozygosity of Tyr68 Cys / IVS3-1G>A, Val252 Met / IVS2+5G>T, Val281 Phe / Cys135 Arg, Ala294 Val / Val281 Phe, Ala294 Val;404delC / Val281Phe, Ala294 Val;404delC / Arg152 stop, Ala294Val;404delC / Gln(-35) stop, Ala294 Val / Val252 Met, Ala294 Val / Gly156 Asp, and Thr359 Met / Asp242 His were related to clinical symptoms. Double heterozygotes for Arg247 Cys / IVS2+1G>C, Ala206 Thr / Pro303 Arg, Leu(-20) Pro / Val252 Met as well as IVS7+7 /Ala294 Val, IVS7+7 /Ala206 Thr, and IVS7+7 / Met298 Ile were asymptomatic. The clinical symptomatology is rather poor in correlation with the FVII activity. Concerning the clinical phanotype, a correlation seems to exist between specific mutations and clinical symptoms.