DNA analysis were performed for SERPING1 gene and pathogenic variant hotspots in ANGPT1, F12 and PLG. Pathogenic variant in heterozygous state were identified in PLG gene (NM_000301.5:c.988A > G p.(Lys330Glu) was detected)—molecularly confirming the diagnosis of n-C1-INH HAE. The gene discussed is SERPING1; the disease is hereditary angioedema.