Hum Genet (1993) 92:446-450 human .. geneucs 9 Springer-Verlag 1993 Molecular analysis of factor VII deficiency in Italy: a frequent mutation (FVII Lazio) in a repeated intronic region F. BernardP, P. PatracchinP, D. Gemmati 2, M. Ferrati 1, P. ArcierP, M. PapacchinP, R. RedaellP, E Baudo 4, G. MarianP, G. MarchettP 1 Centro Studi Biochimici delle Patologie del Genoma Umano, Istituto di Chimica Biologica, Universit5 di Ferrara, Ferrara, Italy 2 Istituto di Ematologia e Fisiopatologia dell'Emostasi, Universith di Ferrara, Ferrara, Italy 3Dipartimento di Biopatologia Umana, Sezione di Ematologia, Universit~aLa Sapienza, Rome, Italy 4 Divisione di Ematologia, Ospedale Niguarda, Milan, Italy Received: 10 March 1993 / Revised: 22 April 1993 Abstract. Molecular defects and polymorphic haplotypes of coagulation factor VII gene were studied in eight unre- lated Italian subjects with factor VII deficiency, seven having the factor VII- variant, one the factor VII R variant. An intron 7 mutation, which alters the consensus donor splice site sequence, was found in six subjects. The pres- ence of the founder effect is suggested by their common geographical origin (a mountain area in the Lazio region) and by the identical polymorphic haplotype underlying the mutation. A different mutation, also located in the 5" monomer of the repeated intron 7 sequence, was found in the heterozygous condition in a subject from Northern Italy. New polymorphic alleles were detected in the re- peated intron 7 region in subjects from Eastern Africa. Two missense mutations in codon 97 (Gly---rCys, Gly--~ Ser), the first found in the compound heterozygous condi- tion with the frequent intron 7 mutation, suggest the pres- ence of a hot spot mutation site in the second epidermal growth factor domain. Two neutral dimorphisms at codon 333Ser and ll5His were detected, the last in linkage dise- quilibrium with the 353Arg/Gln polymorphism, and show- ing differences in frequency in the FVII deficient and con- trol subjects. Introduction Factor VII (FVII) is a vitamin K-dependent serine pro- tease glycoprotein (Broze and Majerus 1980) with a piv- otal role in the initiation of blood coagulation. Circulating FVII zymogen is activated (FVIIa) by the hydrolysis of a single peptide bond (Radcliffe and Nemerson 1976) and in turn activates factor IX (FIX) or factor X (FX) (Lawson and Mann 1991) in the presence of tissue factor (TF) (Rao and Rapaport 1988). The primary structure of FVII, deter- Correspondence to: F. Bernardi, Centro di Stndi Biochimici delle Patologie del Genoma Umano, Istituto di Chimica Biologica, Uni- versit5 di Ferrara, Via L. Borsari 46, 1-44100 Ferrara, Italy mined by cDNA sequencing (Hagen et al. 1986), reveals the presence of a gamma-carboxyglutamic acid (Gla) do- main, two epidermal growth factor (EGF) domains, and a catalytic domain. The gene (symbol "F7") consists (O'Hara et al. 1987) of nine exons and eight introns spanning 12.8 kb and its organization is homologous to FIX, FX, and protein C, thus suggesting a common origin by gene duplication (Long 1986). F7 polymorphisms caused by point muta- tion (Green et al. 1991) and the insertion of a de- canuleotide have been described (Marchetti et al. 1993). In addition, F7 contains a large number of repeats, and variations in the monomer number have been reported (O'Hara and Grant 1988; Marchetti et al. 1991, 1992). FVII deficiency (Alexander et al. 1951; Hedner and Davie 1989) is inherited as an autosomal recessive disor- der with variable expression, characterized by decreased FIX activation in vivo (Bauer et al. 1990). The most fre- quent FVII deficiency (Mariani and Mazzucconi 1983) is characterized by parallel levels of FVII clotting activity and antigen, and has been defined as "cross reacting ma- terial negative". Functional FVII variants have been de- scribed (Girolami et al. 1982) and gene alterations have recently been detected (Chain and High 1991; O'Brien et al. 1991; Marchetti et al. 1992; Millar et al. 1992). In this study, F7 mutations and their genetic background were analyzed in eight unrelated Italian patients. Materials and methods Patients Eight subjects with homozygous or heterozygous FVII deficiency and five family members were studied. Five subjects were affected by severe (< 2% FVII:C) Fu deficiency and, on clinical grounds, were all clearly symptomatic (hemarthrosis, epistaxis, menorrha- gia, gingival bleeding, muscle hematomas). Of these, four had very low levels of antigen. One of the patients (PC) had detectable (10%) levels of antigen and a mild bleeding tendency, character- ized by gingival bleeding and abundant menses. One subject (SC)