Cystinosis Awareness Day Date in the current year: May 7, 2025

Cystinosis is one of many lysosomal storage disorders, rare metabolic diseases that result from defects in the function of lysosomes. Lysosomes are organelles that break down large molecules and send their fragments to other parts of the cell. When they don’t work properly, these large molecules accumulate in cells and cause extensive damage to tissues and organs.

Cystinosis is characterized by the abnormal accumulation of the amino acid cystine, which is highly insoluble and therefore rapidly crystallizes when accumulated in large amounts. The accumulation of cystine is caused by mutations in the CTNS gene, which encodes the protein responsible for transporting cystine across cell membranes.

Cystinosis is an autosomal recessive genetic disorder, which means that a person must inherit a faulty copy of the gene from both parents in order to show symptoms. It is an extremely rare disorder, diagnosed in only about 2,000 people worldwide. Its incidence is disproportionately high in the French region of Brittany (1 in 26,000 individuals compared to 1 in 100,000 to 200,000 births worldwide).

There are three different types of cystinosis: infantile nephropathic, late onset (adolescent, intermediate) nephropathic, and ocular (non-nephropathic). Patients with infantile nephropathic cystinosis usually develop Fanconi syndrome between 6 and 18 months of age. In people with Fanconi syndrome, nutrients (glucose, minerals, amino acids) are excreted in the urine instead of being reabsorbed in the renal tubules of the kidney. Major symptoms include frequent urination, constant thirst, dehydration, poor growth, weak or soft bones (rickets), muscle weakness, fatigue, and acidosis. By about two years of age, cystine crystals may also accumulate in the cornea of the eyes, causing extreme sensitivity to light (photophobia).

The signs and symptoms of late-onset nephropathic cystinosis are the same as those of infantile nephropathic cystinosis, but they develop at about 12 to 15 years of age. In patients with ocular cystinosis, the kidneys are not affected; the only symptom is sensitivity to light caused by cystine crystals in the cornea.

If left untreated, nephropathic cystinosis can lead to complete renal failure by the age of 10 in patients with infantile cystinosis or by the late teens to mid-twenties in patients with late-onset cystinosis. The disease is usually treated with cysteamine, which helps remove excess cystine. It is available in capsules for kidney symptoms and in eye drops for eye symptoms. People with cystinosis may also receive medications to treat individual symptoms, such as acidosis or hypophosphatemia (low blood phosphate levels). If kidney function becomes severely impaired, a kidney transplant may be needed.

Cystinosis Awareness Day was created to raise awareness of this rare disease and advocate for better access to diagnosis and treatment. You can get involved by learning more about cystinosis and sharing what you’ve learned with others, donating to an organization that supports patients or funds research, and spreading the word on social media using the hashtag #CystinosisAwarenessDay.