Snyder-Robinson syndrome is a genetically triggered disease. The disease usually occurs enormously rarely in the general population. The typical leading symptoms of the disease consist of mental retardation, difficulty walking, hypotonia of the muscles, osteoporosis, and an often asymmetrical face.
What is Snyder-Robinson syndrome?
Snyder-Robinson syndrome received its name in reference to the two physicians who first described the condition. This initial description was made in 1969 by Snyder and Robinson. In English, the disease is referred to as spermine synthase deficiency, among other terms. The disease is characterized by a spectrum of symptoms and signs, which sometimes occur in various combinations. In addition, the individual symptoms often vary from patient to patient in terms of their severity. Basically, Snyder-Robinson syndrome is a very rare disease. Affected individuals are usually mentally retarded, suffer from considerable difficulty walking and running, and have comparatively brittle bones. This is because affected patients are particularly prone to osteoporosis. The tone of the musculature is often not as pronounced as in healthy people, so that the diseased persons are comparatively weak. This circumstance is usually already noticeable in childhood. Sometimes the persons show a so-called kyphoscoliosis and show an asymmetry in the area of the face.
Causes
In principle, Snyder-Robinson syndrome represents a very rare genetic disease. The prevalence of the disease is now estimated to be less than 1:1,000,000. In addition, numerous studies of patients and their families indicate that the disease is inherited in an x-linked recessive manner to the children. Basically, the cause of Snyder-Robinson syndrome is to be found in genetic mutations. According to current knowledge, these mutations occur on the so-called SMS gene and in particular on the gene locus Xp22.11. This gene locus is responsible for coding. This gene segment is responsible for the coding of the so-called spermine synthase. As a result of the mutation, disorders in spermine synthase occur in the course of the disease.
Symptoms, complaints, and signs
In Snyder-Robinson syndrome, affected patients suffer from various complaints and symptoms of the disease. Depending on the individual case, these symptoms may vary in severity. The combination of different signs of the syndrome also varies in many cases among affected individuals. Basically, the affected patients show a so-called asthenic stature. In the majority of cases, mental development is slowed down. Many patients have a pronounced mental retardation. Many patients suffer from kyphoscoliosis and difficulties in speaking. Particularly in the facial region, affected individuals often exhibit significant anomalies. For example, asymmetry of the face is typical, as is a conspicuous lower lip area. Osteoporosis associated with the disease makes the affected individuals particularly prone to fractures of bones. They also frequently suffer contractures of joints.
Diagnosis and course of the disease
Some of the characteristic symptoms of Snyder-Robinson syndrome appear immediately after birth or in early childhood. These primarily include abnormalities of the face. Weakness of the muscles is also usually noticeable in young children and directs suspicion to a hereditary disease, since the symptoms are present from birth. During the anamnesis, the attending physician clarifies the patient’s complaints, whereby in the majority of cases the parents of the affected child play a decisive role. They inform the physician about the onset and severity of the symptoms. The disease is diagnosed with the help of numerous methods of examination techniques. First, the physician approaches the signs of the disease in the normal course of visual examinations. In this process, the anomalies of the face, for example the typical asymmetry, are the main focus of observation. Osteoporosis is detected, among other things, with examinations of the density of the bones.Mental retardation and delayed intellectual development are usually noticeable in early childhood and can be detected with the help of various testing procedures. The joint impairments can be diagnosed, for example, with the use of radiographic examinations or other imaging techniques. Overall, the characteristic association of symptoms points to Snyder-Robinson syndrome. To diagnose the disease with a high degree of certainty, genetic testing is usually used. This allows the responsible gene mutation to be detected at the known gene locus. During diagnosis, the attending physician also performs a differential diagnosis. In doing so, the physician primarily differentiates the disease from Rett syndrome as well as glycerol kinase deficiency. In addition, monoamine oxidase A deficiency and Prader-Willi syndrome must be ruled out.
Complications
As a rule, affected individuals with Snyder-Robinson syndrome suffer from a number of different complaints that can lead to significant limitations and discomfort in everyday life. Patients usually suffer from significantly delayed development. Even in adulthood, severe limitations and thus mental retardation occur. Often, the children are thus dependent on special support and on the help of other people in their everyday lives. Significant complaints and complications also occur in speech and communication. Due to the facial anomalies and deformities, many children also suffer from bullying or teasing. This can also lead to psychological discomfort or depression. Furthermore, those affected by Snyder-Robinson syndrome are very susceptible to bone fractures and can thus easily injure themselves. The joints are also often weakened and the fingers can be overstretched very easily. Usually, Snyder-Robinson syndrome cannot be treated causally. Affected individuals are dependent on various therapies in their lives that can limit the symptoms. Furthermore, in many cases the parents or relatives of the patients also suffer from severe psychological symptoms. However, the patient’s life expectancy is not reduced by Snyder-Robinson syndrome.
When should you see a doctor?
People with Snyder-Robinson syndrome usually face doctor consultations right after birth because of this rare inherited condition. However, at this time, only some of the typical symptoms are visible. It is also possible that the first warning signs do not become manifest until infancy. In this case, the first doctor’s visits occur later. Snyder-Robinson syndrome can be recognized by certain abnormalities and asymmetries in the face, as well as striking muscular weakness. The child’s parents should go to a specialist immediately if they notice such signs, as in all likelihood it is a serious disorder or illness in their young child. Accurate observation and documentation of the observed abnormalities will provide crucial clues for the physician called in. The specialist consulted will perform various examinations to determine the cause of the presenting symptoms. These include, for example, visual findings, bone density measurements or special test procedures that detect a mental disability. X-rays can be used to document the joint impairments that are typical of Snyder-Robinson syndrome. In sum, a clear picture then emerges. This ensures the diagnosis “Snyder-Robinson syndrome”. A genetic test can provide the final clue if there is still any doubt. It is possible that the disease is confused with Rett syndrome, glycerol kinase deficiency, monoamine oxidase A deficiency or Prader-Willi syndrome. All have similar symptomatology in visual findings.
Treatment and therapy
Snyder-Robinson syndrome is not yet treatable causally, so only the symptoms of the disease are treated. By means of special care and support for the affected individuals and the administration of appropriate medications, the symptoms are partially reduced. With regard to the mental disability, the affected persons usually receive instruction in a special school and special educational care. Various physiotherapeutic measures are also applied to some patients.
Prevention
Snyder-Robinson syndrome is hereditary, so currently no effective prevention of the disease is possible or has been tested.
Aftercare
Follow-up care in Snyder-Robinson syndrome is used for early detection of typical complications and to support patients in their daily lives. In addition, therapy is adjusted to symptoms during follow-up. Patients with Snyder-Robinson syndrome require both physiotherapeutic aftercare and mental support. Typical complications that need to be clarified during follow-up care are bone fractures or joint contractures due to osteoporosis. At regular intervals, a specialist must examine the stability of the bones. If necessary, physiotherapy is then prescribed. After a surgical procedure, such as may be necessary to correct facial abnormalities, follow-up care in the hospital is indicated. Depending on the type of surgery, the patient may need to stay in the hospital for several days to weeks. During the follow-up, the wound healing is checked and finally the result of the corrective surgery is assessed. Patients with a pronounced asthenic physique also require comprehensive physiotherapy, which often lasts for years or decades. Follow-up care is provided by the responsible specialist. This usually involves several specialists such as neurologists, chiropractors and orthopedists. Follow-up care for Snyder-Robinson syndrome lasts a lifetime due to the distinct nature of the symptoms. Individual symptoms can be treated over the long term, but others recur or can only be marginally alleviated by therapy.
What you can do yourself
Provided there is a known diagnosed case of Snyder-Robinson syndrome within the family, couples should seek consultation with a physician before planning to have offspring. This is considered helpful in clarifying the risk and estimating further development. The hereditary disease is accompanied by reduced mental capacity. This leads to the fact that the affected persons themselves are hardly or not at all able to apply self-help measures on their own responsibility. For this reason, relatives and medical professionals are responsible for establishing an optimal treatment plan as well as everyday life for the affected person. In most cases, early intervention programs are implemented. Relatives can also independently perform exercises and training sessions with the affected person outside of the therapies to improve the general health development. It is important that family members know and respect their own limits when caring for the patient. A balance to the care of the affected person is important to avoid situations of excessive demands. A disorder of speech is characteristic. Therefore, a very own communication should be established in everyday life. This helps to identify the wishes and needs of the ill person. In addition, when coping with everyday life, it is important to find a way of good exchange.
