Alports syndrome is -

Ans. is 'a' i.e., X linked Alport's syndromeo Alport's syndrome is a type of hereditary nephritis characterized by -i) Glomerulonephritis progressing to chronic renal failure,ii) Nerve deafnessiii) Eye defects lenticonus, lens dislocation, posterior cataract, corneal dystrophy,o Most commonly it is inherited as X-linked form.o Rare autosomal - recessive and autosomal-dominant pedigrees also exist.Pathogenesiso There is defective GBM synthesis because of production of abnormal collagen type IV underlies the renal lesions,o The defect is caused by mutation in the gene encoding a-chain of collagen type IV.o Manifestations of Alport's syndrome are due to abnormal a. (COL4A3)y or, (COL4A4), or orf (COL4A5).o This is due to mutations of:COL4A5 in classic X-linked formCOL4A3 or COL4A4 in autosomal forms.Histological characteristics of Alport - syndrome:* Diffuse basement membrane thinningo Foam cell in interstitium - Due to accumulation of neutral fat and mucopolysaccharideo In advanced stage there is focal or global glomerulosclerosis,o Vascular sclerosiso Tubular atrophyo Interstitial fibrosiso The GBM shows irregular foci of thickening alternating with thinning, with pronounced splitting and lamination of the lamina densa, often with a distinctive basket - weave appearance.