The mean age of onset of ESRD in our group of patients harboring a combination of COL4/LAMA5 variants (II;2, II;3, II;4; II;5 in family 1 and II;2 in family 2) is 45 years, in line with previously reported data about collagen 4 chains-related digenic inheritance [13, 14], suggesting to suspect a digenic inheritance when the age of the renal failure onset is intermediate between an autosomal dominant and a recessive form. The gene discussed is LAMA5; the disease is Renal insufficiency.