Renal disease in patients with Alström Syndrome (AS)

Mamiko Uchida Hopkinson Department of Internal Medicine Kitasato University Sagamihara City Kanagawa, Japan.

AS is a very rare (affecting around 170 individuals in the world), autosomally recessively inherited, multi-system disorder. Kidney dysfunction has been reported in 56-80% of AS patients, but detailed renal histological analysis has been reported in only 4 cases, so much of the description in this abstract is based upon general principles. Early renal disease is usually asymptomatic; whereas, moderate and severe renal disease is characterized by ankle swelling and malaise. Biochemical changes of severe renal disease include: proteinuria; aminoaciduria; and increased plasma urea and creatinine. Renal disease specific investigations include: renal ultrasound; and renal biopsy. In chronic renal failure associated with AS, ultrasound reveals small kidneys, and renal biopsy characteristically shows glomerulosclerosis, tubular sclerosis, tubular atrophy and interstitial fibrosis, consistent with focal segmental glomerulosclerosis. The histological findings (3 x renal biopsy, 1 x autopsy specimen) in the 4 cases mentioned were consistent with the findings described above for chronic renal failure.

The clinical management of renal failure in AS is based on general principles in view of the small number of cases that have been reported. In the case of mild renal failure, regular physical examination, urinalysis, and plasma sodium, potassium, urea and creatinine estimations should be performed. In moderate renal failure, management of hypertension by non-pharmacological or pharmacological means and a low-sodium diet is required. Severe renal failure would require the treatment of obvious causes

e.g. pharmacological causes, avoidance of nephrotoxic drugs, treatment of hypertension, a low salt and low protein diet and temporary or permanent dialysis. The development of more specific guidelines for the treatment of renal disease in AS will require the recognition and reporting of renal disease in future AS patients.