The kidneys are primarily involved in the filtration of blood and the pumping of ions and molecules, and many disorders arise through defects in specific transporters, especially ion channels or aquaporins. The normal action of the kidneys is important for regulating blood volume and hypertension is often treated with diuretics that stimulate excretion of water. The natriuretic peptides and kallidin, angiotensin, renin, aldosterone, vitamin D, and parathyroid hormone regulate renal function. Renal tubular acidosis can arise from mutation in carbonic anhydrase or in V-type ATPase. The filtration function depends on specialized basal lamina in the glomerulus (see podocytes) and this can be ‘clogged’ if there are circulating immune complexes (see glomerulonephritis, Goodpasture's syndrome). Many disorders have renal dysfunction as one of a range of symptoms, e.g. arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, Barttin's syndrome 4, cystinosis, Fanconi's syndrome, focal segmental glomerulosclerosis, GATA-3, Henoch–Schönlein purpura, hypomagneaemia with hypocalcuria and nephrocalcinosis, nephronophthisis, polycystic kidney disease, pseudohypoaldosteronism, tuberous sclerosis, hyperuricaemia, uromodulin, Wilms' tumour. Development of the kidneys is defective in Potter's syndrome and renal tubular dysgenesis. Renal cell carcinomas arise from cells of the proximal tubule cells and are the commonest of the tumours of the kidney in adults. Obsolete names include hypernephroma and Grawitz's tumour. Pax 2 is mutated in renal–coloboma syndrome (papillorenal syndrome) in which there is a gap in the structure (coloboma) of the optic nerve and renal disease.
Subjects: Medicine and Health.