Categories: Renal / urinary system phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 305800 (trait)

Mendelian trait/disorder: unknown

Disease-related: yes

Cross-species summary: A chronic, slowly progressive inflammation of the capillary loops in the glomeruli of the kidney, in which the glomeruli are enlarged as a result of proliferation of mesangial cells and thickening of the capillary walls, which narrows the capillary lumina. The type I variant of this disorder is characterised by a double-contour appearance of the capillary walls. Affected animals die after a brief clinical episode which includes anorexia and signs of central nervous system distrubance. On post mortem, the kidneys are dramatically enlarged, with pale spotted cortices. Glomeruli show a thickening of the capillary walls, proliferation of mesangial cells and matrix, and formation of epithelial crescents. There may be focal haemorrhage and oedema evident on histopathological examination of the brain. The damage to the kidneys and brain are thought to be due to deposition of immune complexes (IgA, IgM, and IgG) and complement. [Researched and prepared by Philippa Beard]

Species-specific description: This disorder becomes clinically apparent when lambs are 1-3 months old. Affected lambs are born with a severe deficiency of the third component of complement (Gardiner, 1985), but the relevance of this is not known. (Not all lambs with this congenital complement deficiency develop the clinical disease.) Type I mesangiocapillary glomerulonephritis is strongly familial in Finnish Landrace purebred and crossbred flocks, but a single-locus pattern of inheritance has not yet been determined (Young et al., 1981; Angus, 1990). This ovine disorder appears to be a good model for the same disorder in humans (Angus, 1974; Frelier, 1990), for which X-linkage has been claimed, but not proven. [Researched and prepared by Philippa Beard]