1/4. Stones, bones, and heredity.Genetic disorders of mineral metabolism cause urolithiasis, renal disease, and osteodystrophy. Most are rare, such that the full spectrum of clinical expression is difficult to appreciate. diagnosis is further complicated by overlap of clinical features. Dent's disease and primary hyperoxaluria, inherited causes of calcium urolithiasis, are both associated with nephrocalcinosis and urolithiasis in early childhood and renal failure that can occur at any age but is seen more often in adulthood. Bone disease is an inconsistent feature of each. Dent's disease is caused by mutations of the CLCN-5 gene with impaired kidney-specific CLC-5 chloride channel expression in the proximal tubule, thick ascending limb of Henle, and the collecting ducts. Resulting hypercalciuria and proximal tubule dysfunction, including phosphate wasting, are primarily responsible for the clinical manifestations. Low-molecular-weight proteinuria is characteristic. Definitive diagnosis is made by dna mutation analysis. Primary hyperoxaluria, type I, is due to mutations of the AGXT gene leading to deficient hepatic alanine-glyoxylate aminotransferase activity. Marked overproduction of oxalate by hepatic cells results in the hyperoxaluria responsible for clinical features. Definitive diagnosis is by liver biopsy with measurement of enzyme activity, with dna mutation analysis used increasingly as mutations and their frequency are defined.These disorders of calcium urolithiasis illustrate the value of molecular medicine for diagnosis and the promise it provides for innovative and more effective future treatments.- - - - - - - - - - ranking = 1keywords = kidney (Clic here for more details about this article) |
2/4. Congenital hypoplastic anemia, diabetes, and severe renal tubular dysfunction associated with a mitochondrial dna deletion.Mitochondrial dna (mtDNA) deletion is associated with a variety of clinical entities. In addition to progressive external ophthalmoplegia and kearns-sayre syndrome, mtDNA deletions have been demonstrated in Pearson's syndrome. We report an mtDNA deletion in an infant with a variant of Pearson's syndrome. Not only does she have congenital anemia, severe tubulopathy, and exocrine pancreas insufficiency, but she also has diabetes and cerebral atrophy. However, there are no signs of gut or liver involvement. bone marrow improved while new tissues were involved, thus showing variability in progression of the disease. Decreased respiratory chain enzyme activities were demonstrated in muscle, and an mtDNA deletion was demonstrated in muscle, kidney, leukocytes, and fibroblasts.- - - - - - - - - - ranking = 1keywords = kidney (Clic here for more details about this article) |
3/4. The congenital "magnesium-losing kidney". Report of two patients.A 39-year-old man with a lifelong history of tetany and hypocalcaemia was found to have hypomagnesaemia (0.29 mmol/l) due to renal magnesium loss. His asymptomatic 29-year-old brother had a similar disorder. Both were infertile and had severe oligospermia but normal endocrine function. They had medullary nephrocalcinosis and glomerular filtration rate was reduced. Renal biopsy showed patchy interstitial fibrosis and some glomerular sclerosis. Electron microscopy showed thickened basement membranes in damaged glomeruli and in tubules in areas of fibrosis. Tests of renal tubule function were normal. Hypocalcaemia and tetany were corrected by oral magnesium supplements which raised the serum magnesium level to around 0.54 mmol/l.- - - - - - - - - - ranking = 4keywords = kidney (Clic here for more details about this article) |
4/4. Clinicopathological studies of oculo cerebrorenal syndrome of Lowe, Terrey and MacLachlan.A thirty-three-year-old male with Lowe's syndrome had cataract; nystagmus, buphthalmos, prominent frontal bossing, growth and mental retardation, aminoaciduria, proteinuria, rickets, areflexia, genu valgum, piercing cry and head-banging being among the presenting features. The rickety changes improved over a period of years with the administration of vitamin D2. Pathological changes include: (1) tubular damage in the kidneys and hypertrophies of Bowman's capsules; (2) small brain with ventricular dilatation with thickened meninges, small corpus callosum, small size of pyramidal tracts and medial leminisci, neurofibrillary tangles in the pyramidal cells of the Ammon's horn and frontal lobe; (3) eye changes of buphthalmos, congenital cataracts and thickening of Descemet's membrane; (4) testicular atrophy--both testes showing peritubular fibrosis with an increase of fibrous tissue in the interstitial tissue. azoospermia was present linked with poor development of spermatogonia and spermatocytes. The lumina of the seminiferous tubules were filled with foamy exudate.- - - - - - - - - - ranking = 1keywords = kidney (Clic here for more details about this article) |