Cystinosis

Logan Donahue

What is Cystinosis?

It is a very rare disease only affecting around 500 people nationally and 2,000 people internationally. Cystinosis is usually only found in children. Cystinosis is caused when there is a build up of the amino acids called Cystine. These amino acids have no transport back out of the cell once they are inside. This build up can severely damage the cells, which then leads to tissue damage and then ultimately organ damage and or failure. The organs most effected by Cystinosis are the eyes, brain, kidneys, and liver. Muscles can also begin to build up with the Cystine crystals. Since it is such a rare disease, it is extremely hard to find funding to find a cure for Cystinosis. Cystinosis is an autosomal recessive gene which has to be passed down through both parents, and even then only has a 1/4 chance that the child will get it.

external image cystinosis.jpg
Cystine crystals-----------No Cystine crystals

On a molecular level

Cystine amino acids are transported into the cells cytoplasm. The transporters to get them back out are defective when born with this disease. While they keep getting pumped into the cell, they start to build up and crystallize as you see in the eye above. The Cystine concentrate in the cells can get 50-100 times stronger than normal before the cell eventually dies.
Lysosomes are small bundles of enzymes inside a cell that regulate macromolecules in and out of the cell. Then through the hydrolytic digestion process the lysosomes are either sent out of the cell or recycled and used again inside the cell. Cystinonsis disease is a defect in the lysosomal cystine transport. This means that the door that lets the cystine amino acids is shut and locked.

Symptoms and effects

Most children with the disease are born normally and don't show signs until 9-10 months after birth. A majority of disease carrying children are diagnosed with the disease before they reach the age of two. Signs to look for that may be the result of Cystinosis are: excessive thirst, excessive urination, trouble swallowing, diabetes, pale skin, slowed growth, and a loss of phosphorus throughout the body which leads to rickets. Rickets are the weakening and softening of bones due to loss of phosphorus. There are 100s of other symptoms like infertility, constipation, and craving of salt to name a few. As you can see the symptoms have no pattern and can be pretty abnormal. One of the main problems is the kidneys are not able to absorb any nutrients which end up getting lost in the urine. This leaves the child very weak and sets his or her kidneys to fail by the age of 10 if not treated properly.

Symptoms and effects of a child with Cystinosis

external image Boy-diagram-FPO-1_real.jpg


Treatment

Treating Cystinosis is more of an annoying process than a difficult one. Multiple times every single day the person with the disease must drink plenty of water, electrolytic drinks, multiple vitamins, and phosphorus caplets. CYSTAGON, a pill made almost entirely of Cysteamine, is a drug taken by a lot of patients to help deplete the amount of Cystine amino acids that build up in your cells. Not only does CYSTAGON help deplete the amino acid build up but it helps bring back your appetite, aids in development, helps bone growth, quenches thirst, slows down the need to urinate, etc... It pretty much aids you in living the life of a person without the disease.

Below is the molecule Cysteamine which is the drug that helps people with Cystinosis get through every day life
external image Cysteamine-3D-balls.png

Cystinosis video


Works Cited

http://www.cystaran.com/glossary.php#rickets (Explanation of rickets)
http://www.cystinosisresearch.org/about-cystinosis/ (Cystinosis information)
http://emedicine.medscape.com/article/981650-overview (Cystinosis information)
http://www.raredr.com/articles/CRF-2Million (Picture of eye comparison)
http://www.cystaran.com/what_is_cystinosis.php (Picture of child and symptoms)
http://en.academic.ru/dic.nsf/enwiki/1742468 (Picture of Cysteamine molecule)