Alport syndrome (AS) is a hereditary condition in which abnormal type IV collagen is produced and results in defective basement membranes of multiple organ systems. The mode of inheritance is X chromosome-linked dominant in approximately 85% of cases and autosomal recessive in the majority of remaining cases. AS is a nonimmune hereditary glomerulonephritis associated with hematuria, proteinuria, and variable degrees of sensironeural deafness, ocular abnormalities (anterior lenticonus, retinal flecks of the macular and mid-peripheral retina, and nontraumatic recurrent corneal erosion), and progression to end-stage renal disease (ESRD).

Auditory and ocular abnormalities are not present in all patients, and hearing loss associated with renal disease may be seen in other conditions (Charcot-Marie-Tooth Disease, branchio-oto-renal syndrome, Muckle-Wells syndrome, Alström syndrome, renal tubular acidosis, and IgA nephropathyHematuria is an extremely common manifestation of AS (nearly 100% in males and approximately 90% in females) and is glomerular in origin (associated with dysmorphic urinary RBCs, proteinuria, and RBC casts). Progressive azotemia resulting in eventual ESRD usually at a young age is inevitable in male patients; however, uremia is rare in female patients and occurs later in life if it does manifest. Proteinuria is a common finding and varies in intensity.  The level may vary from barely detectable to the nephrotic syndrome. Heavy proteinuria and an increase in the severity of proteinuria are poor prognostic signs. Renal biopsy specimens show characteristic structural glomerular lesions by electron microscopy with a lack of immunologic lesions on direct immunofluorescence. Indirect immunofluorescence of biopsies from kidney or skin will show type IV collagen alpha chain expression.

Laboratory abnormalities include the above mentioned hematuria, proteinuria and uremia. Thrombocytopenia with large platelets being noted on peripheral smear may also be associated with AS but is usually not associated with an increased bleeding tendency.

There is no treatment for curing this condition. Supportive therapy is aimed at aggressive control of blood pressure. Once patients manifest ESRD, dialysis or renal transplantation may be offered. A few patients with AS may develop posttransplant antiglomerular basement membrane nephritis.