Hereditary zinc deficiency syndrome represents a hereditary disorder of zinc absorption in the intestine. The same symptoms develop as in acquired zinc deficiency syndrome. The disorder is very treatable by lifelong zinc supplementation.
What is hereditary zinc deficiency syndrome?
The term hereditary zinc deficiency syndrome describes a hereditary disorder in the absorption of zinc in the intestine. In this case, the body absorbs too little zinc. In this syndrome, the same symptoms occur as in acquired zinc deficiency. The disease was first described in 1936 by the Swedish physician Thore Edvard Brandt. The Norwegian physicians Karl Philipp Closs and Niels Christian Gauslaa Danbolt coined the term acrodermatitis enteropathica for this syndrome in 1942. Synonyms for the hereditary zinc deficiency syndrome are therefore, in addition to acrodermatitis enteropathica, also the terms Brandt’s syndrome and Danbolt-Closs syndrome. Zinc represents an essential trace element, which plays a major role in many metabolic processes in the organism. Many enzymes responsible for carbohydrate, fat and protein metabolism contain zinc. In addition, zinc is also involved in the synthesis of nucleic acids and in cell growth. The immune system and various hormones also depend on the trace element zinc for their function. Furthermore, zinc is a component of certain proteins (zinc finger proteins) that are responsible for transcription. Due to this universal importance of the trace element zinc for metabolism, a zinc deficiency leads to serious health disorders.
Causes
The cause of hereditary zinc deficiency syndrome is a gene mutation in the SLC39A4 gene, which is located on chromosome 8. This gene encodes the zinc transport protein ZIP4. In the absence of this protein, the absorption process of zinc in the intestine is disturbed. Despite sufficient intake of zinc in the diet, a zinc deficiency syndrome then develops. Normally, external factors are responsible for zinc deficiency. However, in only one to nine cases per million people, this zinc deficiency is congenital. The disease is inherited in an autosomal recessive manner. Both parents can be healthy. However, if one offspring has the disease, both parents also have at least one defective gene. Healthy parents with a defective gene have a 25 percent chance that their child will have hereditary zinc deficiency syndrome.
Symptoms, complaints, and signs
The symptoms of hereditary zinc deficiency syndrome are similar to those seen in acquired zinc deficiency. However, symptoms in this congenital condition begin shortly after weaning. Breast milk is rich in zinc and can still provide adequate absorption of zinc in the body despite the zinc absorption disorder. However, after weaning, the skin changes, hair loss, nail bed inflammation and diarrhea begin. The skin changes manifest themselves as chronic eczema on the orifices of the body and the acra such as hands, feet, nose, ears, chin, zygomatic bone and many others. The organism is severely immunocompromised. Therefore, sufferers suffer from constant infections that are difficult to heal. Wound healing is also severely limited. Children with hereditary zinc deficiency syndrome no longer grow. Their physical and mental development is severely slowed. Other symptoms include anemia, loss of appetite, weight loss, fatigue, general weakness and muscle wasting. Recovery from illness is very slow. In addition, there is irritability and depression. Mental deterioration progresses. The prognosis for untreated hereditary zinc deficiency syndrome is very poor. In these cases, the disease is always fatal. However, with proper treatment, the patient can lead an almost normal life.
Diagnosis and course
However, for successful treatment of hereditary zinc deficiency syndrome, it must be diagnosed without doubt. This is not so simple. Because of the rarity of the condition, misdiagnoses are often made initially. Moreover, all the symptoms that occur are not specific. A variety of diseases can be behind it. It is true that early-occurring eczema on the orifices and the acras may raise suspicion of zinc deficiency. However, secondary streptococcal infections and candidiasis very often obscure the diagnosis.A strong indication of a hereditary zinc deficiency syndrome is the sudden appearance of the skin changes shortly after weaning. The history of the family medical history is often helpful. Here it could turn out that several cases of similar diseases have already occurred in the family or relatives. This would indicate a hereditary disease. In addition to the chronic skin changes, an increased susceptibility to infections and slow wound healing are also indicative of a possible zinc deficiency. The suspicion of zinc deficiency can then be confirmed by blood tests. In addition to the zinc content, the hormone cortisol and the number of blood cells are also determined. There are usually 6 to 12 milligrams of zinc per liter in the blood. The blood cells are reduced. However, the blood values are also not 100 percent meaningful because most of the zinc is stored in muscles, bones and other body tissues. Muscle accounts for 60 percent, bone for 30 percent and other body tissue for 10 percent of the zinc contained in the body.
Complications
Because there is usually reduced absorption of zinc by the intestine in this disease, the same complaints occur as in the usual zinc deficiency syndrome. In this case, the affected person primarily suffers from hair loss and diarrhea. Furthermore, complaints can also develop on the skin, resulting in eczema, for example. Not infrequently, the skin is also covered with a rash. The patient’s immune system is weakened by the zinc deficiency syndrome, so that infections and inflammations can occur more often and more easily. Furthermore, only a slowed wound healing occurs in the affected person. This can also lead to infections at the wounds. Due to the loss of appetite, patients suffer from weight loss and general fatigue and exhaustion. Not infrequently, this can also result in psychological upsets or depression. Zinc deficiency syndrome can be relatively well limited and treated by the administration of supplements. The symptoms disappear very quickly and there are no particular complications. However, the affected person is dependent on the medication for the rest of his life, since a causal treatment of zinc deficiency syndrome is not possible.
When should one go to the doctor?
Parents who notice symptoms such as hair loss, skin changes, and nail bed inflammation in their child shortly after weaning should consult their pediatrician. The complaints indicate a hereditary zinc deficiency syndrome, which must be clarified and treated immediately. A visit to the doctor is particularly indicated if the complaints have not subsided after two to three days at the latest. If further symptoms such as diarrhea or poor wound healing occur, a doctor must be consulted immediately. Anemia, loss of appetite, weight loss and fatigue are also typical warning signs that need to be clarified. Since those affected often suffer from irritability and depression, a psychologist should be consulted to accompany the medical treatment. In any case, a hereditary zinc deficiency syndrome requires comprehensive treatment. After the original disease has been cured, close monitoring by a specialist is indicated, as the symptoms may recur. Persons suffering from the disease who wish to have children should talk to their doctor. In addition, it must be determined during pregnancy whether the disease has been passed on to the child. Thus, treatment can be initiated immediately after birth.
Treatment and therapy
Hereditary zinc deficiency syndrome can be treated very well by high doses of zinc in the form of zinc sulfate. In this context, the administration of zinc supplements must be adapted to the growth process. Thus, in childhood and adolescence, increased zinc administration is necessary. Zinc substitution must be lifelong and must not be suspended.
Outlook and prognosis
Individuals with hereditary zinc deficiency syndrome suffer from a congenital metabolic disorder. Even young children show the typical symptoms. With appropriate therapy, there is a good chance of a normal life. However, a cure is impossible. The disorder in zinc absorption is passed on to the patients at birth. From a statistical point of view, it hardly occurs if one looks at the absolute numbers of sufferers.Just one to nine people out of one million suffer from hereditary zinc deficiency syndrome. Patients need to take zinc supplements regularly. The dose must be adapted to the stage of development. Growth phases in particular entail a high requirement. If the prescribed preparations are consumed continuously, a largely symptom-free life is possible. Without taking them, death is almost always imminent. Affected persons are then at a disadvantage if they have an infection or wounds. The hereditary zinc deficiency syndrome ensures that recovery is delayed. It is not uncommon for affected children and adolescents to develop comparatively slowly. This refers to both physical and psychological maturity. Mild to severe immunodeficiency depends on the form of the day.
Prevention
There is no recommendation for prevention of hereditary zinc deficiency syndrome because it is a hereditary condition. If cases of this condition have already occurred in the family or relatives, human genetic counseling is recommended if the patient wishes to have children.
Follow-up care
In most cases, the affected person has no measures of aftercare available in zinc deficiency syndrome, since primarily the absorption of the element must be restored. The affected person should therefore see a doctor at the first symptoms and signs of the disease in order to prevent further complications or discomfort. The sooner a doctor is contacted, the better the further course is usually. Since zinc deficiency syndrome is a genetic disease, the affected person should consider genetic testing and counseling if he or she wishes to have children, so that the syndrome does not recur in descendants. In most cases, the affected person with zinc deficiency syndrome must take medications and supplements to counteract the zinc deficiency. No particular complications occur. Care must be taken to ensure correct dosage and also regular intake, following the doctor’s instructions. As a rule, those affected by zinc deficiency syndrome are dependent on taking the medication for the rest of their lives. Parents must pay attention to the correct intake, especially in their children. As a rule, the syndrome does not reduce the life expectancy of the affected person.
What you can do yourself
Hereditary zinc deficiency syndrome results from a hereditary disorder of zinc absorption in the intestine. The symptoms are the same as those of acquired zinc deficiency. There are no causally effective self-help measures that affected individuals can take. However, taking high doses of zinc, for example in the form of zinc sulfate, can eliminate the zinc deficiency. If the hereditary zinc deficiency syndrome has already been diagnosed, over-the-counter dietary supplements can also be used in emergencies or during vacations. Hereditary zinc deficiency already presents in infants, usually immediately after weaning. If the disease is recognized promptly and treated adequately, no late damage is to be feared. However, if left untreated, the disease leads to severe developmental disorders in the child and ultimately to death. Since it is a hereditary disease, people in whose families the syndrome has already occurred should familiarize themselves with the symptoms as soon as they plan to have offspring. They can then promptly identify the rare disease and ensure that their child is properly treated. Otherwise, because the disease is very rare, it can take a long time to be correctly diagnosed, which can lead to mental and physical developmental problems in the affected child.
