Alport Syndrome

Definition, EtiologyTop

Alport syndrome (AS) is a hereditary nephropathy caused by abnormal synthesis of type IV collagen alpha chains, which leads to damage of the glomerular basement membrane. AS is mostly commonly X-linked (in ~80% of patients). A fully symptomatic disease occurs in men, while women are carriers or have a milder form of the disease. Other types of AS have autosomal inheritance, occur in both sexes, and have a course similar to X-linked AS.

Clinical FeaturesTop

Microscopic hematuria and proteinuria are observed. End-stage renal disease (see Chronic Kidney Disease) occurs in almost all men and usually develops by their early- to mid-30s. Most patients have high-frequency sensorineural hearing loss. Various ocular lesions, such as anterior lenticonus, can occur.

TreatmentTop

There is no curative therapy for AS; however, a therapy with angiotensin-converting enzyme inhibitors (ACEIs) likely delays renal failure and improves life expectancy.Evidence 1Strong recommendation (benefits clearly outweigh downsides; right action for all or almost all patients). Moderate Quality of Evidence (moderate confidence that we know true effects of the intervention). Quality of Evidence lowered due to observational data; increased from low to moderate due to sibling control and effect size. Gross O, Licht C, Anders HJ, et al. Early angiotensin-converting enzyme inhibition in Alport syndrome delays renal failure and improves life expectancy. Kidney Int. 2012 Mar;81(5):494-501. doi: 10.1038/ki.2011.407. Epub 2011 Dec 14. PMID: 22166847.