BIOCHEMICAL FOLLOW-UP IN LATE-TREATED NEPHROPATHIC CYSTINOSIS

Nephropathic cystinosis (McKusick 219800) is an autosomal recessive di sease due to impaired cystine transport across lysosomal membranes. Cy stine storage causes multisystem organ damage, starting with renal tub ular involvement (Fanconi syndrome) with growth failure. Glomerular fu nction gradually declines, leading to uraemia and death by 9-10 years of age unless dialysis or renal transplantation is performed (Adamson et al 1989; Schneider et al 1990). Early initiation of therapy with cy steamine has been reported to preserve glomerular function and improve growth (Gahl et al 1987), but the benefit is not so clear when the tr eatment starts at a later stage (Reznik et al 1991).