ClinVar

Description

The F7 c.1091G>A (p.Arg364Gln) missense variant, also commonly referred to in the literature as p.Arg304Gln or the "Pauda" variant, has been reported in at least eight studies in which it is identified in at least 70 individuals, including 11 clinically symptomatic homozygotes and two clinically symptomatic compound heterozygotes (Ding et al. 2003; Marty et al. 2008; Girolami et al. 2011; Rabelo et al. 2015). The p.Arg364Gln variant has also been reported in at least 19 clinically asymptomatic homozygotes with lower factor VII activity than wildtype (O'Brien et al. 1991; Girolami et al. 2011; Rabelo et al. 2015). The variant is present at a frequency of 0.00908 in the African population of the 1000 Genomes Project. This allele frequency is high but may be consistent with disease prevalence and the fact that many individuals with factor VII deficiency are clinically asymptomatic. Girolami et al. (2011) found the mean levels of activated FVII in six homozygotes to be significantly lower than the activated FVII levels in 21 normal controls. Further, the variant was associated with reduced factor VII activity when assayed with rabbit brain thromboplastin, however, the activity levels varied between the use of human placenta, recombinant human or ox-brain thromboplastin (O'Brien et al. 1991; Kirkel et al. 2010; Girolami et al. 2011; Girolami et al. 2011; Rabelo et al. 2015). Based on the collective evidence, the p.Arg364Gln variant is classified as a pathogenic risk factor for factor VII deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population.