What do we know about chronic renal failure in young adults? I. Primary renal disease.

Paediatric registries worldwide report that congenital abnormalities of the kidney and urinary tract (CAKUT) account for approximately 50% of end-stage renal failure and other congenital and familial diseases account for another 20% (together 70%). Does the same hold true for young adults? Almost nothing has been published about primary renal disease in adults who have reached end-stage before 30 years of age. I have reviewed the UK renal registry (2000-2006) and the United States Renal Data System (USRDS) data base (2005) to answer this question. While paediatric registries have reduced the number of children with 'no specific diagnosis' from 39% in 1976 to fewer than 5%, the adult registries still report rates of 20-27%, which rise to 28-36% when all unspecified groups, predominantly 'glomerulonephritis (GN) (histologically not examined)', are considered together. For UK data, this rise in 'no specific diagnosis' mirrors a fall in CAKUT to 26% for the age group 18-21 years. According to USRDS data, CAKUT falls from 31% for ages 0-19 years to only 5% for ages 20-30 years. Nephrologists probably under-diagnose CAKUT in young adult patients, and this diagnosis can account for many of the 30% that currently have no specified primary renal disease.