Cystinosis is a rare but very dangerous metabolic disease. In its course, the amino acid cystine accumulates in excess in the body. It damages numerous organs - mainly the kidneys and eyes - and thus they stop functioning properly. What are the causes and symptoms of cysinosis? How is her treatment going?
Cystinosisis a genetically determined metabolic disease, the essence of which is the deposition of excess cystine in various organs, mainly in the kidneys and eyes. As a consequence, they become damaged and their work is gradually disrupted. Cystine is an amino acid formed by combining two cysteine molecules - an amino acid that performs the body's defense functions, binding many poisonous substances (e.g. heavy metal ions, arsenic compounds, cyanides).
There are three types of disease:
- nephropathic (renal) cystinosis
- indirect cystinosis
- non-nephropathic (ocular) cystinosis
Cystinosis belongs to the group of rare diseases. Occurring with the frequency of approx. 1: 200 thousand. births.
Cystinosis - causes
The cause of cystinosis is a mutation in the CTNS gene. As a result of this defect, cystine deposits build up in many organs. The defective gene is inherited in an autosomal recessive manner, i.e. a copy of the damaged gene must be inherited from each parent for symptoms of the disease to develop.
Cystinosis - symptoms
1. Nephropathic (renal) cystinosis - occurs in infants
- lack of appetite and weight gain
- polyuria
- excessive thirst
- tendency to constipation
- if cystine builds up in the cornea, symptoms such as eye pain and photophobia, decreased visual acuity
The course of the disease developsFanconi syndrome- disorders of the renal tubules, which leads to the loss of various valuable substances (vitamins, minerals, etc.) in the urine, which results in a disorder child growth, rickets. If not treated properly, the baby will develop kidney failure, and the sooner symptoms appear, the faster it occurs.
In addition, other organs may be damaged and disturbed, e.g. hypothyroidism, hypogonadism, pancreatic damage and mild diabetesmuscle weakness, liver enlargement.
2. Indirect cystinosis - appears in adolescence
The same symptoms appear as in the course of renal cystinosis.
3. Ocular cystinosis - is diagnosed at different ages
- deposition of cystine in the cornea of the eye
- there is usually no kidney damage
Cystinosis - diagnosis
If cystinosis is suspected, ophthalmological, kidney and other examinations are performed (depending on the organ in which cystine accumulates). Final diagnosis is made on the basis of genetic testing.
Cystinosis - treatment
In the treatment of nephropathic and indirect cystinosis, cystagon (cysteamine) is used - a drug that limits the accumulation of cystine in the body. Besides, it is necessary to hydrate, replenish bicarbonate, phosphate, vitamin D and others (as needed).
Patients with ocular cystinosis are administered cystarate - an ophthalmic cysteamine solution.