Sotos syndrome is a rare genetic disorder. It is characterized by accelerated body growth and somewhat delayed motor and language development in childhood. In adulthood, the typical symptoms are hardly noticeable.
What is Sotos syndrome?
Sotos syndrome represents a sporadically occurring rare malformation syndrome. In this condition, accelerated growth with disproportionate skull circumference (macrocephalus) and advanced (accelerated) bone age occurs beginning prenatally. Motor, cognitive and language development is slowed. In adulthood, normal intelligence often develops and typical physical symptoms become inconspicuous. Sotos syndrome was first described in 1964 by the American endocrinologist Dr. Juan F. Sotos. He identified the typical symptoms of the disease in five children. In the meantime, more than 200 cases have been described. The disease is very rare. Its frequency is about 1 in 14,000 newborns. There is no family history of the disease. The disease occurs sporadically and is usually a new mutation. Sotos syndrome is also known as cerebral gigantism.
Causes
The cause of Sotos syndrome in the majority of cases is a point mutation in the NSD1 gene on chromosome 5, with about 10 percent of cases being a deletion at this gene. The disease is inherited in an autosomal dominant manner. It usually occurs as a new mutation (de novo). The corresponding gene encodes a histone methyltransferase that is involved in the regulation of transcription. The descendants of affected individuals can inherit 50 percent of the disease according to the autosomal dominant mode of inheritance. The risk of recurrence of Sotos syndrome is less than one percent in healthy parents.
Symptoms, complaints, and signs
Sotos syndrome is characterized by excessive growth in childhood. Accelerated growth is already observed prenatally, so that birth often has to be induced prematurely. Bone growth is also accelerated. The biological bone age is higher than the chronological age. The face acquires a characteristic shape. is long and narrow with a broad and domed forehead and a high forehead hairline as well as a pointed chin. A cranial anomaly develops with increased distance between the eyes and a widened bridge of the nose (hypertelorism). The palate is high and pointed and there is early eruption of the teeth. The body length is excessive with a large head circumference. These symptoms are very typical and suggest a diagnosis of Sotos syndrome early on. However, there are also non-constant symptoms that occur to varying degrees in individual affected individuals. Thus, heart defects, scoliosis, malformations of the urogenital tract, increased tendon reflexes or seizures may occur. The risk for various tumors is often increased. Motor and cognitive development is delayed to varying degrees from patient to patient. Developmental delays are common in fine and gross motor skills. There are problems with coordination of movement and concentration. Learning to speak is also delayed, with greater speech comprehension. However, all developmental milestones can be achieved despite the slowed development. Children with Sotos syndrome have widely varying intelligence quotients. Mental retardation is not typical for the disorder, but may occur. The children’s behavior is also often not conspicuous. However, in individual cases, tantrums and aggressive behavior, sleep problems, low social contact, and obsessive-compulsive behavior have been reported. The extent to which these personality disorders are related to Sotos syndrome is not clear. It is also conceivable that it is the result of possible exclusion. Perhaps some caregivers overestimate the independence of the children due to the accelerated body growth. This can create the danger of excessive demands and lead to aggressive behavior on the part of the children. However, some difficulties may also arise during the children’s development. For example, cramps, febrile convulsions, neonatal jaundice, sucking difficulties with drinking and breathing problems, and frequent upper respiratory tract infections are common in newborns.Due to the advanced bone age in Sotos syndrome, the onset of puberty is also premature.
Diagnosis and course of the disease
Even the characteristic symptoms of accelerated body growth quickly lead the physician to make a tentative diagnosis of Sotos syndrome. Differential diagnoses to Sotos syndrome such as Weaver syndrome, Beckwith-Wiedemann syndrome, fragile X syndrome, Simpson-Golabi-Behmel syndrome, or deletion 22qter syndrome should be excluded. Furthermore, the NSD1 gene can be tested for a gene mutation.
Complications
Because of Sotos syndrome, affected children suffer from significantly delayed development. This complaint can also have a very negative impact on adulthood, causing symptoms even in older age. As a rule, the patients are also dependent on permanent help from parents or relatives. They suffer from heart defects and often from seizures. Mental retardation also occurs, so that those affected suffer from problems with coordination and thinking. Likewise, tantrums or general aggressive behavior occur. The affected children also suffer from sleep problems and are very often irritable as a result. Due to the respiratory problems, many activities or sporting activities are not readily possible for those affected, resulting in significant restrictions in everyday life. The respiratory tract is frequently affected by infections and inflammations. Treatment of Sotos syndrome is purely symptomatic and is usually not associated with complications. However, this syndrome results in a reduced life expectancy of the patient. Because of various measures that should be taken, especially in early childhood, many everyday complaints can be alleviated.
When should one go to the doctor?
In Sotos syndrome, medical treatment by a doctor is always necessary. In this case, there can be no independent cure, so the patient is always dependent on treatment by a doctor. Only early detection of the syndrome can prevent further complications. Since it is a genetic disease, it cannot be completely or causally treated. A doctor should be consulted for Sotos syndrome if the affected person suffers from significantly accelerated growth. In this case, the individual body parts are also excessively large, which can usually be seen directly with the eye. Furthermore, heart problems or severe cramps often indicate Sotos syndrome. Also tumors or a strong mental handicap can point to the Sotos syndrome and should always be examined by a physician. It is not uncommon for those affected to also show aggressive behavior or other mental disorders. At the first signs of Sotos syndrome, a general practitioner or a pediatrician can usually be consulted. Further treatment depends on the exact symptoms and is carried out by a specialist.
Treatment and therapy
Causal treatment of Sotos syndrome is not possible. Multidisciplinary treatment of patients from the beginning is important. However, only symptomatic therapies can be performed. Already in infancy, depending on the complications, phototherapies for jaundice, treatment of drinking difficulties, and control of blood glucose levels with regard to possible hypoglycemia are necessary. General pediatric check-ups should detect complications such as scoliosis or febrile convulsions in order to initiate therapies as soon as possible. Due to the developmental delays, early support measures should be undertaken with the help of occupational therapy, speech therapy, early intervention or music therapy. All support measures should be planned depending on the child’s stage of development. The prognosis of the disease is good. In adulthood, Sotos syndrome usually reaches a normal developmental level with appropriate support. Physical symptoms also become inconspicuous.
Prevention
Prevention from Sotos syndrome is not possible. It is a genetic disorder that usually occurs sporadically. However, because Sotos syndrome is inherited in an autosomal dominant manner, the children of a parent with the disease may be affected in 50 percent of cases.
Aftercare
As a rule, there are very few or no special and direct measures and options of aftercare available to the affected person in Sotos syndrome, so the affected person should ideally see a doctor very early in this disease to prevent the occurrence of other complaints and complications. There is also no complete cure, as this is a hereditary disease. For this reason, if the affected person wishes to have children, he or she should definitely have a genetic examination and counseling to prevent the Sotos syndrome from recurring in the descendants. Since there is no independent cure, the affected person should consult a doctor at the first symptoms and signs of the disease. The affected persons are dependent on different therapies, by which the complaints can be limited. Sometimes the help and care by the own family is very important and useful and can help to prevent the development of depression and other physical complaints. As a rule, contact with other sufferers of Sotos syndrome is also very useful, as this often leads to an exchange of information.
What you can do yourself
Patients diagnosed with Sotos syndrome should be advised that with advancing age, some complaints will normally regulate themselves again. In particular, accelerated growth does not normally present further impairments in adolescence or, at the latest, in adult life. Therefore, children should be fully informed about the symptoms of the disease. In addition, people from the close social environment should also be informed about the health disorder as well as the further development. This procedure prevents unpleasant situations and can be very helpful for the child in coping with the disease in everyday life. Since there are problems with movement, it is also advisable for parents to practice motor skills with the child on a daily basis. Although the treatment plan provides for physiotherapeutic measures, targeted training should also be carried out independently and on one’s own responsibility in everyday life. This improves mobility and supports well-being. In dealing with the patient, calmness and sovereignty are particularly important. Behavioral problems can be very stressful for all concerned. Regular time off helps especially the guardians to better cope with the adversities. Since a large number of those affected depend on support from their social environment for the rest of their lives, social stability should be established early on.
