A 20-year-old male is presented with end stage renal failure. Since 13 years of age, he has had progressive renal insufficiency initially with episodes of painless haematuria. He also has progressive deafness. His brother suffers from similar illness. What is the most likely diagnosis -

AIpo's syndrome A number of uncommon diseases may involve the glomerulus in childhood but the most impoant one affecting adults is Alpo's syndrome. Most cases arise from a mutation or deletion of the COL4A5 gene on the X chromosome, which encodes type IV collagen, resulting in inheritance as an X-linked recessive disorder (p. 48). Mutations in COL4A3 or COL4A4 genes are less common and cause autosomal recessive disease. The accumulation of abnormal collagen results in a progressive degeneration of the GBM (Fig. 15.14). Affected patients progress from haematuria to ESRD in their late teens or twenties. Female carriers of COL4A5 mutations usually have haematuria but less commonly develop significant renal disease. Some other basement membranes containing the same collagen isoforms are similarly involved, notably in the cochlea, so that Alpo's syndrome is associated with sensorineural deafness and ocular abnormalities. Angiotensin-conveing enzyme (ACE) inhibitors may slow but not prevent loss of kidney function. Patients with Alpo's syndrome are good candidates for renal replacement therapy (R), as they are young and usually otherwise healthy. They can develop an immune response to the normal collagen antigens present in the GBM of the donor kidney and, in a small minority, anti-GBM disease develops and destroys the allograft. Ref Harrison20th edition pg 298