Definition
The term storage disease covers a number of diseases in which the disturbed metabolism leads to deposits of certain substances in the organs or cells. Depending on the substance and organ, storage diseases can vary greatly in their severity and form. Some storage diseases are already apparent at birth and require immediate therapy, whereas others only appear in the course of life.
What storage diseases are there?
Iron storage disease – Hemochromatosis Copper storage disease – Wilson’s disease Protein storage disease Glycogen storage disease Lysosomal storage disease Cholesterol ester storage disease Myocardial storage disease Neutral fat storage disease
- Iron storage disease – Hemochromatosis
- Copper storage disease – Wilson’s disease
- Protein storage disease
- Glycogen storage disease
- Lysosomal storage disease
- Cholesterol ester storage disease
- Myocardial storage disease
- Neutral Fat Storage Disease
Iron storage disease, known in specialist circles as hemochromatosis, is a metabolic disorder in which there is an increased deposition of iron in the body and in certain organs. In most cases, the iron storage disease is a hereditary defect that leads to an excessive absorption of iron via the gastrointestinal tract. The excess iron cannot be excreted as quickly as it is absorbed and is therefore deposited in various organs.
Depending on the affected organ and the amount of iron, a variety of symptoms of hemochromatosis and complaints may subsequently occur. In rare cases, the iron storage disease can also occur as a consequence of another underlying disease or as a consequence of frequent blood transfusions, the so-called secondary hemochromatosis. The additional iron stored in organs that do not normally serve as iron stores leads to remodelling processes.
During these conversion processes, a form of scar tissue is formed which replaces the healthy organ tissue and thus reduces the functionality of the organ. Very often, hormone-producing organs in the abdomen are affected, such as the liver (most frequently) or the pancreas. But organs such as the heart, skin and pituitary gland are also among the most frequently damaged organs.
The course of the disease is usually insidious and is therefore often only detected in an advanced stage of the disease. The symptoms here depend on the extent of the damage and the organs affected. Typical at the beginning are general complaints such as exhaustion and tiredness.
In the course of the disease, joint pain in the finger joints, especially in the index and middle finger, and a conspicuous brown coloration of the skin develop. With the help of blood tests and special biopsies of individual organs, a precise diagnosis can be made as to which organs are affected and to what extent. The most frequent and typical organ manifestations are, first of all, the liver with cirrhosis of the liver, which is a high risk factor for the development of liver cancer, and the pancreas with diabetes mellitus.
The possibilities for therapy of iron storage disease are limited to regular excretion of excess iron. A causal cure is not yet known. In the first place, a low-iron diet is recommended, as well as regular consumption of black tea, as it lowers the absorption of iron in the intestine.
If increased iron levels occur despite a low-iron diet, bloodletting is the method of choice. In this case 500 ml of blood is taken from the patient, whereby iron bound to the blood cells is lost. Once the target value for iron in the blood has been reached, bloodletting every 2-3 months with close laboratory controls is recommended.
In women of childbearing age, this intervention can often be dispensed with, as the menstrual bleeding leads to sufficient iron loss. Iron-binding drugs are available as an alternative to bloodletting, but these are only used if bloodletting is not feasible, for example due to anaemia or other underlying disease. With early diagnosis and consistent therapy, patients with an iron storage disease have a normal life expectancy.Copper storage disease, known as Wilson’s disease, is a metabolic disorder caused by the disturbed excretion of copper.
This is caused by a hereditary genetic defect for a protein that prepares copper for excretion via the bile. If there is a defect, copper can no longer be excreted in sufficient quantities. It accumulates in the bloodstream and as a result is deposited in various organs.
Typically, copper is deposited mainly in the liver, cornea, red blood cells and brain. In particular the infestation of the liver and the brain in combination lead to typical symptoms, which lead to the suspected diagnosis of a copper storage disease. The first symptoms often occur between the ages of 5 and 10, for example in the form of inflammation of the liver, known as hepatitis, or neurological limitations caused by reduced liver function, such as drowsiness and shaky hands.
From the age of 10, typical neurological symptoms also occur, such as fine-pitch hand trembling, dementia, swallowing or speech disorders, and gait problems. In addition, copper deposits in the eye can become visible. Here a green-brown ring appears in the cornea.
With the help of blood and urine tests, possibly a biopsy of the liver and various imaging techniques, the diagnosis of copper storage disease can be confirmed. The primary therapy for a confirmed diagnosis of copper storage disease consists of a combination of a low-copper diet and medications that serve to excrete copper, the so-called chelating agents, e.g. D-penicillamine. The prognosis of the disease is good with early and consistent therapy.
It is only important to make an early diagnosis before organ damage can occur due to the copper deposits. The following applies here: any unclear liver disease that is not based on an infection, in combination with unclear movement disorders before the age of 45, should be clarified with regard to copper storage disease. The so-called protein storage disease is not a recognized clinical picture according to the World Health Organization.
Rather, it is a concept developed and published by Prof. Dr. Lothar Wendt. In his work, Prof. Wendt pursued an alternative approach to explaining common diseases in our society, contrasting the view of classical orthodox medicine with the question of “what for”. A typical example of this approach can be seen in the widespread disease diabetes.
Diabetes mellitus type 2 leads to greatly increased blood sugar levels. These elevated blood sugar levels lead to damage throughout the body with serious secondary diseases. The conventional medical approach is therefore to consistently lower the blood sugar level in order to prevent further damage.
Professor Wendt however questions in his working concept, why it comes to these increased blood sugar values, and whether the reason for this could be a compensation. He puts forward the theory that protein deposits in the walls of the blood vessels cause them to thicken. Prof. Wendt now explains that the increased blood sugar levels are a reaction to the thickened blood vessel walls in order to transport a sufficient amount of sugar into the cell despite the increased resistance and longer diffusion path.
According to Wendt, it is therefore not the sugar that is the disease-causing factor, but the protein and finally the term diabetes that is misleading. The term increased blood sugar level as consequence of a causal protein storage disease would be more appropriate according to its concept. At present, however, there is a lack of evidence-based studies that would support this explanatory approach and the concept of the disease.
Only in the therapy of arthrosis there are already patients in some self-help groups who report that they have alleviated or even eliminated arthrosis by means of a targeted protein breakdown therapy. However, it should be noted that these are individual experiences without a reference group, which were only successful if the therapy was started at a very early stage of the disease. Leading professors from various specialist departments, taking into account the current study situation, see no evidence for the correctness of Prof. Wendt’s concept of protein storage disease.
In glycogen storage diseases, an inherited genetic defect leads to an excessive deposition of glycogen in the body.Glycogen is colloquially also called liver starch. This is a long and multi-branched glucose molecule, which is stored in the liver and serves as a provider of the energy source sugar. There are a total of nine different forms of glycogen storage disease, each of which is based on a different genetic defect and leads to the deposition of glycogen in different organs.
The most common forms include type I von Gierke’s disease, type II Pompe disease, and type V McArdle’s disease. The different forms differ both in their symptoms and the onset of the disease. Type I glycogen storage disease is usually characterized by an enlarged liver and a distended abdomen, in addition to frequent seizures and a tendency to bleed.
Type II glycogen storage disease is characterized by muscle atrophy throughout the body and an oversized tongue. Type V glycogen storage disease also causes generalized muscle atrophy, but in combination with muscle pain and cramps after exertion. The therapy of glycogen storage diseases depends on the type of disease and its degree of severity.
The term lysosomal storage disease covers a large group of diseases that are based on a genetic defect of the lysosomes. Lysosomes are a group of cells in the human body that act like the stomach or the trash can of cells. In the lysosomes, all excess cell components and waste products of the cell are broken down.
If the lysosomes are defective, these waste products of the cell accumulate and are deposited in the cell as well as in other organs. Currently, 45 diseases are classified as lysosomal storage diseases. Most diseases are very rarely occurring variants of the storage disease.
The most frequently occurring forms of lysosomal storage diseases are Gaucher’s disease and Fabry’s disease. In Gaucher’s disease, the disrupted degradation processes lead to an accumulation of fats in the cells and other organs. The symptoms vary greatly due to the potential infestation of the entire body.
Typical symptoms are an enlargement of the liver and spleen, disorders in the haematopoietic system and seizures. Often the disease is already noticeable in infancy due to a feeding disorder. Fabry’s disease, on the other hand, is much rarer than Gaucher’s disease and mainly affects boys due to its inheritance.
The symptoms of Fabry’s disease initially include burning pain attacks in the fingers, gastrointestinal complaints and corneal clouding. Later, the heart may be affected by cardiac insufficiency and strokes. Cholesterol ester storage disease belongs to the group of lysosomal storage diseases, a rare, hereditary metabolic disease.
Cholesterol ester disease is caused by a defect in lysosomal acid lipase, which normally breaks down fats such as cholesterol esters and triacylglycerides. The reduced breakdown of these fats leads to an accumulation of fats in the cell and, as a result, in the body’s circulation. This disease does not cause any complaints for a long time, only the reactive enlargement of the liver can lead to a feeling of pressure in the right upper abdomen, nausea or a feeling of fullness.
Blood tests show elevated blood values for cholesterol and lipids as well as lowered values for good fats (HDL). Ultrasound examination of the upper abdomen may reveal fatty liver. The therapy of cholesterol ester storage disease is carried out by inhibiting the absorption of cholesterol with colestyramine or ezetimib and additionally by lowering the blood fat values with statins, such as simvastatin.
In myocardial storage disease, there are deposits of waste products in the heart walls, which can severely restrict the heart’s performance and pumping function. Two different storage diseases can lead to these deposits in the heart walls: the rare and hereditary lysosomal storage disease Fabry’s disease and the so-called amyloidosis. In Fabry disease, an inherited genetic defect leads to a reduced breakdown of metabolic products, which as a result are deposited in the heart walls and can cause severe damage.
Amyloidosis, on the other hand, can be both hereditary and acquired in the course of life.In this clinical picture, too, deposits of abnormally altered metabolites occur, which, in addition to other organs, accumulate mainly in the heart, where they severely restrict heart function. Myocardial storage disease is initially conspicuous by general symptoms such as weakness and exhaustion. Over time, increasing breathlessness after exertion and at some point at rest is added.
Water in the lungs, abdomen, legs and pericardium are typical side effects as the disease progresses. For a clear diagnosis of myocardial storage disease, imaging procedures and a heart muscle biopsy are necessary. The subsequent therapy is then carried out on the basis of the triggering underlying disease.
Neutral fat storage diseases are very rare diseases in which the breakdown and storage of a fat, the so-called triglyceride, is defective. To date, only 50 cases of neutral fat storage diseases have been described worldwide. The cause of the genetic defect is, as with most storage diseases, also hereditary in neutral fat storage diseases.
Often the disease is already conspicuous in early childhood due to a developmental disorder. Most of those affected develop an enlargement of the liver with an accompanying liver dysfunction, as well as eye problems and hearing loss. At an advanced age, muscular atrophy and gait disorders may occur.
