Alport Syndrome: From Genes to Bedside

Abstract

Alport syndrome (AS) is an inherited disorder characterized by the familial occurrence in successive generations of progressive nephritis with hematuria and of neural hearing loss. 1 Male patients usually have severe renal disease with progressive renal failure occurring before the fourth decade, whereas most females tend to have a normal life span. The first symptoms, usually consisting of microscopic or macroscopic hematuria, occur in early life, especially in males. Hematuria may in rare cases be observed at birth. Other presenting symptoms of AS include proteinuria, edema, hypertension, deafness and renal failure. Hearing defects may not be present in all affected members of a family and are more frequent in male patients. However, the real incidence of hearing loss is difficult to evaluate in the absence of systematic audiological studies. Associated changes in other organs, such as eyes or smooth muscles, and cell types, such as platelets and granulocytes, are known to occur in some patients with AS. The disease follows an X-linked trait in approximately 80% of the cases, whereas autosomal recessive, autosomal dominant and uninformative pedigrees account for the remainder. 2