VKORC1 and CYP2C9 Polymorphisms: A Case Report in a Dutch Family with Pulmonary Fibrosis.

Here, we describe a Dutch family with idiopathic pulmonary fibrosis (IPF). We hypothesized that there might be an association between the presence of Vitamin K epoxide reductase complex 1 (VKORC1) and/or cytochrome P450 2C9 (CYP2C9) variant alleles and the early onset of IPF in the members of this family. VKORC1 (rs9923231 and rs9934438) and CYP2C9 (rs1799853 and rs1057910) were genotyped in this family, which includes a significant number of pulmonary fibrosis patients. In all family members, at least one of the variant alleles tested was present. The presence of the VKORC1 variant alleles in all of the IPF cases and CYP2C9 variants in all but one, which likely leads to a phenotype that is characterized by the early onset and progressive course of IPF. Our findings indicate a role of these allelic variants in (familial) IPF. Therefore, we suggest that the presence of these variants, in association with other pathogenic mutations, should be evaluated during genetic counselling. Our findings might have consequences for the lifestyle of patients with familial IPF in order to prevent the disease from becoming manifest.

Pharmacogenetic variants and vitamin K deficiency: a risk factor or trigger for fibrosing interstitial pneumonias?

PURPOSE OF REVIEW: Fibrosing interstitial pneumonias are associated with various stages of fibrosis. The cause of this group of syndromes remains largely unknown. For most of these diseases, a genetic basis, environmental factors and certain triggers have been suggested as possible risk factors. Various studies have found an association between genetic polymorphisms, or the presence of certain variant alleles, and the occurrence and/or progression of interstitial pneumonias of unknown origin. An acute exacerbation of idiopathic pulmonary fibrosis shows characteristics of diffuse alveolar haemorrhage (DAH). DAH can be aggravated by vitamin K deficiency. This review deals with pharmacogenetic factors underlying interindividual differences of vitamin K status in patients with interstitial pneumonias and the possibilities for a personalized approach to patient management. RECENT FINDINGS: DAH has been associated with the presence of variant alleles in vitamin K epoxide reductase complex 1, cytochrome P450 (CYP)2C9 and CYP2C19 genes. Vitamin K deficiency has been associated with an increased risk for the development of DAH and progression and/or deterioration of interstitial pneumonias. This is in line with plausible pathophysiological mechanisms. However, clinical use should be confirmed. SUMMARY: DAH has been associated with vitamin K deficiency and suggested as potential trigger of fibrosing interstitial pneumonias. Information on genetic variation might benefit ongoing/new clinical trials, design of which should reflect needs to address relevance of testing gene variants. Whether vitamin K supplementation may prevent exacerbations or progression of interstitial pneumonias needs to be explored in future studies.