Providing Guidance in the Dark: Rare Renal Diseases and the Challenge to Improve the Quality of Evidence

Davide Bolignano; Evi V. Nagler; Wim Van Biesen; Carmine Zoccali


Nephrol Dial Transplant. 2014;29(9):1628-1632. 

In This Article

Rare Renal Diseases

Among renal diseases, over 100 conditions meet the epidemiological criteria to be defined rare, including disorders in development, transport and metabolism.[3] The list comprises the wide spectrum of polycystic kidney disorders, Fabry and Alport disease but also less known and more rare conditions (see Table 1). Some of these diseases selectively affect the kidney, while others may extend to other organs, either before or after renal involvement. In nephrology, rare diseases are mostly genetic so that the terms 'inherited' or 'congenital' are often used interchangeably with 'rare'. Diseases caused by monogenic alterations are less common, often first expressed in childhood and associated with typical phenotypes and weak or no environmental influence. Polygenic disorders are more common, manifest later in life and are strongly influenced by a complex interaction between genetic and environmental factors. Although a single rare disorder of the kidney can hardly be considered to be a public health challenge, however, taken all together, rare renal diseases affect a significant number of individuals with important economic impacts on health services. Collectively, rare renal disorders rank worldwide as the fifth cause of end-stage kidney disease (ESKD) requiring renal replacement therapy after diabetes, hypertension, glomerulonephritides and pyelonephritis with an estimated total contribution of 10% to the annual incidence of ESKD.[4] However, so far, only for few rare renal diseases have disease-specific international registries been established and publically available information on these disorders is often sparse and scarce. Providing evidence-based, balanced recommendations on diagnosis and management of these diseases is therefore a challenging, but necessary task for the renal community.