Steroid-resistant nephrotic syndrome is a rare kidney disease characterized by nephrotic proteinuria, hypoalbuminaemia, oedemas and dyslipidaemia. Searching for genetic forms of the disease among a cohort of 74 Czech and Slovak children, we identified siblings carrying a previously published homozygous causative variant in the COQ2 gene (c.683A>G, p.Asn228Ser).