Nephropathic Cystinosis

Nephropathic cystinosis is the most common and severe form of cystinosis, a metabolic disease characterized by accumulation of the amino acid cystine within lysosomes in the cells, leading to damage in many organs and tissues.^1,2

Nephropathic cystinosis usually presents in early infancy as renal Fanconi syndrome, a serious disorder of the proximal tubules of the kidneys involving excessive excretion of nutrients and minerals such as glucose, amino acids, phosphates, potassium and sodium. This can lead to excessive urination, resulting in acute dehydration. The loss of nutrients impairs growth and may result in soft, bowed bones. Untreated children will experience complete kidney failure by about the age of 10.¹

Nephropathic cystinosis is not only a renal disorder, but a multisystemic disease that could lead to ocular and neurologic impairment, muscle deterioration, diabetes, thyroid and nervous system problems, and infertility in affected men.¹

Transmission is autosomal recessive: two altered copies of the gene from both parents are needed to manifest the disease.¹ It is an ultra-rare disease, with an estimated incidence of around 1/100,000 – 1/200,000 live births.¹

1. Genetics Home Reference. National Institutes of Health. https://ghr.nlm.nih.gov/condition/cystinosis. Last accessed: December 20, 2019.
2. Cystinosis Research Network. https://www.cystinosis.org/support-resources/managing-cystinosis/. Last accessed: December 20, 2019.