What is Rubinstein-Taybi Syndrome?
Rubinstein-Taybi syndrome is an extremely rare genetic pathological condition which is characterized by abnormalities in various organs systems of the body.
The main characteristic features of Rubinstein-Taybi syndrome are delays in development of a child, intellectual disability, failure to thrive, and abnormal facial features to include eyes which are slanted downwards, abnormally long eyelashes, and a smile which looks more like a grimace. There may also be abnormalities in the thumb and fingers of a child with Rubinstein-Taybi syndrome. Dysphagia is yet another common feature of Rubinstein-Taybi syndrome.
A new gene mutation is the main cause for the development of this condition and there is no faulty gene that is inherited from wither parent for the development of Rubinstein-Taybi syndrome. This type of gene mutation is called de novo mutations.
The treatment for Rubinstein-Taybi syndrome is basically supportive and requires a multidisciplinary approach as many organ systems are involved in this condition. Special education is also a necessity as a result of growth delays and intellectual abnormalities. Additionally, cardiac, pulmonary, gastrointestinal, and dental specialists are also required for treatment of a child with Rubinstein-Taybi Syndrome.
What are the Causes of Rubinstein-Taybi Syndrome?
As stated, the cause for development of Rubinstein-Taybi Syndrome is new mutation of the gene CREBBP. This gene mutates in a de novo fashion and is not inherited from either parent but the chances of an individual with his condition having an offspring with Rubinstein-Taybi syndrome is about 50%.
In such cases it follows an autosomal dominant pattern of inheritance meaning that one copy of the faulty gene from the parent is good enough for the offspring to develop Rubinstein-Taybi syndrome.
What are the Symptoms of Rubinstein-Taybi Syndrome?
Since multiple organ systems are involved in Rubinstein-Taybi syndrome thus the symptoms are different for different organ systems of the body. Generally, an individual with Rubinstein-Taybi syndrome will have intellectual disability, growth and developmental delays, problems with speech and communication, abnormally broad fingers and toes, abnormalities of the head and face.
Additionally, there are also abnormalities of the gastrointestinal system with feeding difficulties. Additionally, the bones of the thumb and toes may be malaligned in individuals with Rubinstein-Taybi syndrome. When we break down the symptoms into the respective organ systems then the symptoms of Rubinstein-Taybi syndrome are:
Development: In children with Rubinstein-Taybi syndrome, the height and weight of the child will be much below the normal percentile. The head circumference of the child will also be abnormally low. These children as they grow fail to achieve or have delays in reaching their milestones.
Failure to thrive is common for children with Rubinstein-Taybi syndrome. Weight gain may be a problem initially in the starting phase of this condition but as the child grows he or she will have more weight than their height making them extremely obese.
Feeding difficulties is also seen in children with Rubinstein-Taybi syndrome in the form of dysphagia. Children with Rubinstein-Taybi syndrome also have severe psychomotor retardation.
Such children may also find it difficult to socialize with their peers as they have profound difficulty in communication as a result of Rubinstein-Taybi syndrome. They may also have abnormal muscle tone, unsteady gait, and in some cases seizures as well.
Physical Characteristics: The physical features seen in children with Rubinstein-Taybi Syndrome include a beak shaped nose, a grimacing face. Children with Rubinstein-Taybi syndrome also tend to have an abnormally small head. The upper jaw of the child may also be underdeveloped and the lower jaw will be abnormally small.
Eyes: There are also certain ocular abnormalities associated with Rubinstein-Taybi Syndrome. Such children will tend to have strabismus, ptosis, and epicanthal folds.
Musculoskeletal Deformities: Children with Rubinstein-Taybi syndrome tend to develop scoliosis as they grow as well as kyphosis. There may also be abnormalities of the vertebrae and the pelvis. These children when they grow tend to be prone to frequent dislocations of kneecap.
Genitourinary Tract: Abnormalities of the genitourinary tract are also one of the features of Rubinstein-Taybi Syndrome. Males with this disorder tend to have undescended testicles. They may also have an extra fold of skin at the base of the penis.
Some children also exhibit hypospadias in which the urinary opening is malpositioned. Renal abnormalities are also quite common in children with Rubinstein-Taybi syndrome.
The child may have a malfunctioning kidney or in some cases underdeveloped or absent kidneys which may lead to recurrent urinary tract infections, kidney stones, and abnormal accumulation of urine in the kidneys.
Cardiac: There are also certain cardiac defects associated with children with Rubinstein-Taybi Syndrome. Pulmonary stenosis, patent ductus arteriosus and abnormal heart murmurs are some of the common conditions associated with a child with Rubinstein-Taybi syndrome. Ventral septal defects and atrial septal defects are also common in children with Rubinstein-Taybi Syndrome.
How is Rubinstein-Taybi Syndrome Diagnosed?
Rubinstein-Taybi Syndrome can be diagnosed by the physical features that can be seen as soon as the child is born with characteristic down slanting eyes, grimacing smile, and underdeveloped jaws.
Radiological studies will also be conducted in the form of x-rays studies to look at the status of the bones. A genetic testing will then be conducted which will clearly show a mutation in the CREBBP gene which will confirm the diagnosis of Rubinstein-Taybi Syndrome.
How is Rubinstein-Taybi Syndrome Treated?
The treatment of Rubinstein-Taybi Syndrome is purely symptomatic. The treatment requires a multidisciplinary approach with specialists from multiple specialties coordinating and formulating a treatment plan best suited for the patient.
These will include pediatricians, cardiologists, orthopedists, audiologists, special education specialists, nephrologists and the like. The growth pattern of the child should also be monitored closely. Frequent ocular examinations need also be done to check the status of the eyes and correct the abnormalities if any are present.
The child should be monitored closely for any cardiac, respiratory, and/or renal abnormalities and treated as appropriate with the respective specialists. The skeletal abnormalities associated with Rubinstein-Taybi syndrome can be treated with surgical intervention.
The respiratory and feeding abnormalities will need to be carefully monitored and treated with appropriate interventions. For speech and language difficulties special education will be required so that the patient is made independent enough to put his or her thoughts across and is able to speak and communicate. Genetic counseling is extremely beneficial for families with members who have a member with Rubinstein-Taybi Syndrome.