Definition of storage disorder
Storage disorders are often due to a lack of enzymes, which causes different substances to accumulate in the body's organs. Storage disorders in children include many different diagnoses. Some cases occur spontaneously by mutation, while others are transmitted via inheritance.
- To begin with, the storage disorders can be mistaken for rheumatic disease because joints, back and muscles are affected.
Common traits for storage disorders in children are that they are genetically (hereditary) conditioned and that large molecules (macromolecules) accumulate in the cells. Thus, the function of the affected organs is gradually reduced. The tissue that is attacked is different between the different storage diseases. Often, damage to the liver, spleen and heart occurs, in some cases the brain.
- Most storage diseases are detected at an early age.
- The diseases are genetically (hereditary) caused and separated autoimmune connective tissue disease.
The cause of the disease is the lack of enzymes that should have been produced in the cells. In each condition, it is usually a simple enzyme that does not work normally. Thus, different types of disease occur.
Storage disorders in children have different ages at the onset of symptoms, different severity, and attacks on various organs.
- Delayed development
- Growth disorders (skeleton, joints, muscles)
- Increasing liver and spleen size (hepato-splenomegaly)
- Gradually heart failure
- Reduced hearing and sight
- Pain in the arms and legs
- Seizures (epilepsy-like)
When the symptoms give rise to suspicion of storage disease or hereditary disposition, blood tests are being investigated for enzyme deficiency. In special cases, analyzes of genes can also be done.
The treatment options are different for the different storage diseases. In some cases, stem cell transplantation (from bone marrow or umbilical cord blood) or supplementation of the missing enzymes is used. However, the treatments are not curative.
- However, gene therapy is being researched that can cure some of the diseases. Unfortunately, many children with storage illness die within months to years.
Different types of storage disorder
The different storage diseases can be divided according to the type of molecules that are incorrectly stored in the body. Each disease group has in part many subgroups that constitute the many known diseases. Many are listed in the reference (Reference Wikipedia 2018) Here are the main groups:
Lysosomal Storage Disorders, "Lysosomal Storage Disease, LSD"
In the lysosomal storage diseases, large amounts of molecules are stored in the lysosomes of the cells (between the cell wall and the cell nucleus).
- Lipid (fatty) storage disorder
- Glycoprotein storage disease
- Glycogen storage disease type II (Pompe Disease)
- Cystinosis (Amino acid defect)
Other storage diseases
- Disease in carbohydrate matabilism
- Illness in amino acid metabolism
- Uric acid cycle defective
- Illness in organic acid metabolism (organic acidurias)
- Illness in fatty acid oxidation and mitochondrial metabolism
- Medium-chain acyl-coenzyme A dehydrogenase deficiency(often shortened to MCADD.)
- Illness in porphyrin metabolism
- Illness in purine or pyrimidine metabolism
- Illness in steroid metabolism
- Illness in mitochondrial function
- Illness in peroxisomal function
- Fabry's disease, lack of alpha-galactosiderase (α-Gal A)