<prompt> Mutation in alpha 5 chain of collagen 4, the diagnosisAlports syndromeThin membrane diseaseNodular glomerulosclerosisGood pasture syndrome  <response>: Ans. is a i.e. Alports syndrome Alports syndrome is a hereditary nephritis, characterized byMicroscopic hematuria first symptomQDeafness QPathology of Alports syndromeAlports syndrome is characterized by diffuse glomerular basement membrane thickening.The basement membrane of the glomerulus is made up of type IV collagen.Type IV collagen consists of six differenta chains i.e.a1and a2 located on chromosome 13 col A4A1, col A4A4a3 and a4 located on chromosome 2 col A 4A3, col A 4A2a5 and a6 located on chromosome 6 col A 4A5 col A 4A6a3 a4 and a5 form collagen network present inGlomerular basement membraneCochleaLens capsuleIn Alports syndrome there is defect in the synthesis of type IV collagen Q because there is a mutation in the gene encoding a5 chain of collagen type IV col 4A5These mutations are heterogenous and affect all domains of a5 chain.Because of these defects the glomerular membrane is thin and on electron microscopy it demonstrates irregular foci of thickening alternating with thinning with pronounced splitting of the lamina densa often with basket weave appearance QAlso knowPathogenesis of Good pasture syndromeGood pasture syndrome is an uncommon autoimmune disease, characterized by the presence of circulating autoantibodies targeted against the noncollagenous domain of the a-3 chain of collagen IVQ.These antibodies initiate an inflammatory destruction of the basement membrane in kidney glomeruli and lung alveoli, giving rise to proliferative usually rapidly progressive glomerulonephritis Q and a necrotizing hemorrhagic interstitial pneumonitis Q.Clinical features of Alports syndromeMicroscopic hematuria QHearing loss Q 