Christ-Siemens-Touraine syndrome is an ectodermal dysplasia. The leading symptoms of the disorder are malformations of the skin appendages. Therapy focuses on heat dissipation because patients often do not have fully formed sweat glands and therefore overheat rapidly.
What is Christ-Siemens-Touraine syndrome?
During gastrulation, three so-called cotyledons form during embryonic development. This cotyledon formation occurs through cell migration in early pregnancy and is equivalent to initial tissue differentiation. Prior to cotyledon formation, embryonic cells are omnipotent. In the cotyledons, only multipotent cells are present. This means that the tissues of the cotyledons can only develop into specific body tissues. One of the three cotyledons is the ectoderm. In addition to the skin, the intestinal lining, the nervous system and the adrenal medulla, sensory organs as well as teeth and tooth enamel develop from the ectoderm. Due to various developmental disorders and genetic defects, defects in ectodermal tissue development can occur. Such defects result in ectodermal dysplasias, such as Christ-Siemens-Touraine syndrome. This disorder corresponds to a so-called systemic dyplasia because it affects different body systems. The condition is also called anhidrotic ectodermal dysplasia and corresponds to the most common dysplasia of the ectoderm. Unlike many other ectodermal tissue-based malformations, Christ-Siemens-Touraine syndrome is a genetic defect with a worldwide prevalence of approximately 1 in 10 000.
Causes
Christ-Siemens-Touraine syndrome is a malformation syndrome with a genetic basis. This means that the individual disorders of ectodermal tissue development in this case are due to internal factors and are not primarily related to external factors such as environmental toxins. The complex of symptoms appears to be inherited in an X-recessive chromosomal manner. The basis of the disease is a mutation of different genes passed on the X chromosome. These are the genes XLHED, EDA as well as ED1 with mapping in gene locus Xq12 to Xq13.1. Similar cases have been documented independent of X-linked inheritance. Both autosomal dominant and autosomal recessive transmission is now associated with the syndrome. Mutations in the aforementioned genes alter the genetic makeup, resulting in physiologically unpredictable events. For example, the EDA gene codes in DNA for the protein ectodysplasin-A, which belongs to the tumor necrosis factor-α ligand family. In a healthy organism, this coding produces the gene product ectodysplasin-A, which controls the interaction between mesenchyme and epithelium. Thus, it plays a role primarily in the developmental control of skin appendages, which are misassembled when the gene is defective.
Symptoms, complaints, and signs
Patients with Christ-Siemens-Touraine syndrome suffer from various malformations of the ectodermal tissues. Skin, hair, nails, sweat glands, and sebaceous glands are most severely affected. The core symptoms are hypohidrosis, hypotrichosis and hypodontia, i.e. undercount of teeth, reduced sweat secretion and reduced hair formation. In addition, the skin is dry, scaly and often covered with eczema. Heat adaptations (thermoregulation) are due to low sweat secretion, so fever may occur. Protruding ears at an abnormal depth are common accompanying symptoms, as are underdeveloped eyelashes and eyebrows, colorless main hair, abnormal skin coloration, bulging lips, or saddle noses. In isolated cases, frontal humps are also present. Rather rare associated symptoms include additional eye diseases such as cataract or glaucoma. In other cases, tissue loss at the optic nerve can be observed (optic atrophy). Furthermore, a regression of the retina (retinal degeneration) is conceivable as an ocular symptomatology. In some cases, deafness has been reported in addition to the symptoms described. Short stature may also occur as part of the syndrome.
Diagnosis and course
The diagnosis of Christ-Siemens-Touraine syndrome is made on the basis of the clinical picture. The combination of decreased sweat secretion and abnormalities of hair as well as teeth results in a relatively typical picture. The physician does not always make the diagnosis immediately after birth.In many cases, however, the absence or reduction of sweat glands becomes apparent at the latest in early infancy. A molecular genetic test can be used to confirm the diagnosis. If the test detects mutations in the corresponding genes, the diagnosis is considered proven. The prognosis for patients with Christ-Siemens-Touraine syndrome depends on the severity of the symptoms in each individual case. Cases with a fatal course are known. These cases are usually associated with high fever secondary to thermoregulatory disorders.
When should you see a doctor?
In most cases, Christ-Siemens-Touraine syndrome is diagnosed immediately after birth, so additional diagnosis is usually unnecessary. A doctor must be consulted for this condition if the affected person cannot sweat and thus cannot properly release excessive heat into the environment. Skin and nails are also affected by the syndrome, becoming scaly and dry. In addition, patients often suffer from reduced hair formation, so a medical examination is advisable for this complaint as well. Eye disorders may also indicate Christ-Siemens-Touraine syndrome and should be investigated. Likewise, the syndrome can lead to short stature or deafness, and affected individuals should also consult a physician when these complaints occur. The condition can be diagnosed by a pediatrician or general practitioner. Since there is no direct treatment, sufferers rely on specific ways to cool down. Certain malformations can be treated by the respective specialist.
Treatment and therapy
To date, Christ-Siemens-Touraine syndrome is incurable. A causative therapy does not yet exist. In genetic diseases, any causal therapy would have to target the genes themselves. So far, this has not been possible. It is true that gene therapy approaches have made progress in recent decades and have become a focus of medical research. However, the approaches have not reached the clinical phase. Therefore, patients with Christ-Siemens-Touraine syndrome have so far received only symptomatic treatment combined with supportive treatment steps such as self-help groups. The focus of therapy is on regulating body temperature. Life-threatening conditions can thus be prevented. Evaporative processes are used: to mimic sweating and achieve heat release, the skin of the affected person is moistened, for example. Heat conduction is also used by bringing patients into contact with cool objects. Heat dissipation into moving ambient air can be achieved primarily by drafts, fans, or air conditioning. Patients’ eating and drinking patterns can also be geared toward heat regulation. In order to cool down, those affected drink as much cold water as possible during the day and at night. As a rule, an interdisciplinary team of doctors takes over the treatment. Dental restorations to improve the dental situation, for example, contribute immensely to patients’ quality of life.
Outlook and prognosis
In Christ-Siemens-Touraine syndrome, self-healing does not occur. For this reason, affected individuals are always dependent on medical treatment. However, most of the syndrome’s symptoms can be relatively well limited, allowing patients to lead ordinary lives. Due to the skin discomfort, there is difficulty in heat dissipation, so the sufferers often suffer from fever. The aesthetics of the patient are also negatively affected by the malformation of the hair and the unusual coloring of the skin. Often, this also leads to psychological discomfort. Christ-Siemens-Touraine syndrome can also negatively affect vision, and some patients also suffer from deafness or short stature. These complaints cannot be treated, so that those affected have to struggle with limitations throughout their lives. Usually, the disturbed heat output can be relatively well controlled by eating behavior and by drinking behavior. The environment can also be adjusted to prevent overheating or other discomfort. Although the symptoms cannot be completely limited, the patient’s life expectancy is usually not negatively affected by Christ-Siemens-Touraine syndrome.
Prevention
To date, Christ-Siemens-Touraine syndrome can only be prevented through genetic counseling in family planning.Far more important than prevention can be early detection of the disease, such as in fine ultrasound.
Follow-up care
In Christ-Siemens-Touraine syndrome, in most cases the patient has no or very few measures of direct aftercare available. In this disease, the affected person is primarily dependent on rapid and, above all, early diagnosis and treatment to prevent further complications. Since Christ-Siemens-Touraine syndrome is a congenital disease, it cannot be completely cured. If affected individuals wish to have children, genetic counseling should be provided to prevent the recurrence of this disease. Self-cure cannot occur in this case. Sufferers must properly regulate the release of heat themselves in this disease. The skin can be moistened if it becomes too hot, so that the heat can be released. Likewise, strenuous or physical activities should be avoided so as not to strain the body unnecessarily. Drinking cold water can also alleviate the symptoms of Christ-Siemens-Touraine syndrome. It is not uncommon for contact with other people affected by the syndrome to have a positive effect on the course of the disease, as there is often an exchange of information. Life expectancy is usually not reduced by this disease.
What you can do yourself
Unfortunately, it is not possible to treat Christ-Siemens-Touraine syndrome yourself, leading to a cure. It is based on a mutation of the genetic material, so a cure would only be possible at the genetic level. The affected patients therefore have only the treatment of the symptoms in the sense of a self-therapy. In this respect, the main focus is on influencing the body temperature. Various measures can be taken to counteract the overheating of the body caused by the syndrome. These include, above all, moistening the skin, thus simulating the sweating process, which is usually severely impaired by the disease. Cooling objects pressed onto the skin can also help prevent overheating. The same applies to all means of cooling, whether by air conditioning or simply by drafts. This not only improves the patient’s own body sensation, but also prevents further possible body reactions by dissipating heat. According to the need for cooling, patients are best to take cold drinks and also pay attention to the heat balance of the body when eating. The syndrome is also occasionally accompanied by decreased hair growth on the body; medication can help with this issue.
