Renal tubular disorders

Renal tubular disorders are challenging and, although comprise a heterogeneous group of disorders, this review concentrates on those presenting in childhood with electrolyte abnormalities. Pattern recognition of electrolyte abnormalities is important in making diagnoses and a basic understanding of renal tubular physiology is helpful to understand why these patterns occur.Salt-wasting disorders are the focus of this review. Clinical cases are used as illustrations, supported by physiological descriptions of the disorders and notes about their management.Although these disorders almost invariably come under the long-term management of paediatric nephrologists, they will just as invariably present to general paediatricians. This review should equip general paediatricians with the skills to request the appropriate initial investigations to make the correct diagnosis. There is also some advice on when to suspect a diagnosis of a renal tubular disorder and how to spot a child with a genuine polydipsia.