Thelansis

  Cystinosis is a systemic disease where cystine crystals accumulate in all body cells and tissues and is the most common genetic cause of renal Fanconi syndrome in children. It has 3 major clinical presentations depending on the severity of mutations affecting the CTNS gene: the infantile nephropathic form, the juvenile nephropathic form, and the ocular non-nephropathic form. It is a lysosomal storage disorder caused by mutations in the CTNS gene, encoding for the carrier protein cystinosin, which transports cystine out of the lysosomal compartment. Defective cystinosin function results in intra-lysosomal cystine accumulation in all body cells and organs. The kidneys start affected during the first year of life through proximal tubular damage followed by progressive glomerular damage and end-stage renal failure during mid-childhood if not treated. Other affected organs include the eyes, thyroid, pancreas, gonads, muscles and CNS. Leucocyte cystine assay is the cornerstone for diag...