Researchers have verified two different forms of Robinow syndrome, a very rare genetic disorder that primarily affects stature and bone development. Two common names for Robinow syndrome are fetal face syndrome and Robinow dwarfism.
Definition & Facts
There are two types of Robinow syndrome which differ from each other both in terms of symptom severity and in their heritability. The two types are autosomal recessive Robinow syndrome (also known as COVESDEM Syndrome) and autosomal dominant Robinow syndrome.
Robinow syndrome is so rare that only an estimated 250 cases total have been identified and documented in medical literature. Only 50 of those cases come from autosomal dominant Robinow syndrome and the remaining 200 come from autosomal recessive Robinow syndrome, which is known to be the more severe of the two different kinds of Robinow syndrome, with a greater amount and variety of possible symptoms.
Cases of Robinow syndrome are predominantly found in families with ethnic backgrounds from Turkey, Brazil, Pakistan and Oman. To date, reported cases in males and females are fairly equal in number. In the United States, new reported cases average about just 6 per year (or about 1 in every 500,000 infants).
Symptoms & Complaints
Individuals with Robinow syndrome of either type also tend to have a distinctive-looking configuration of facial features. These features are typically nicknamed "fetal face" and can include each of the following:
- Wide-spaced, large eyes.
- Triangle-shaped, broad and large mouth.
- Broad forehead.
- Short, upturned nose.
- Wide nasal bridge.
- Unusually wide and large head.
Additional symptoms of either type of Robinow syndrome (varying basically in severity) include the following:
- Under-developed genitals at birth (for both females and males).
- Gum overgrowth along with a mouth crowded with teeth.
- Defects in the kidneys and congenital heart defects.
- Delayed growth and development.
- Hemivertebrae which is a type of congenital vertebral anomaly that is characterized by a wedge-shaped, underdeveloped vertebrae).
- Ribs that are missing or fused together.
- A spine that is abnormally curved.
- Permanently bent fifth fingers.
The causes of Robinow syndrome are related to genetic mutations. One type of Robinow syndrome is recessive, which means that both parents must contribute the gene with the mutation before the offspring will develop the syndrome. The other, less common type of Robinow syndrome is dominant, which means only one parent needs to contribute the mutated gene in order for the offspring to develop the syndrome.
In cases of recessive Robinow syndrome, the probability of having a child born with the syndrome is 25 percent. The probability of giving birth to an unaffected child is also 25 percent, as is the probability of birthing a child who becomes a genetic carrier. If there is already one child in the family who has Robinow syndrome, the chances of a second child also developing the condition is 25 percent.
For cases of dominant Robinow syndrome, which is associated with milder symptoms overall, the probability of having a child born with the syndrome is 50 percent.
However, there have been reported cases where an individual spontaneously develops the required gene mutation even when neither parent has the gene to pass along. The reason for these cases of Robinow syndrome currently remains unknown.
Diagnosis & Tests
Diagnosing Robinow syndrome can happen before birth (prenatal diagnosis) or after birth (newborn screening). If done prior to birth, the most common diagnostic test used is ultrasonography. Here, the test will look for distinguishing physical characteristics that match Robinow syndrome symptoms. If done after birth, the most common diagnostic tests used include the following:
- X-rays and imaging tests like computed tomography (CT) scans and magnetic resonance imaging (MRI) scans. These tests look for cranial deformities and spinal deformities as well as abnormalities in bone and facial growth.
- Blood tests. Blood tests will seek to verify abnormally high levels of FSH (follicle-stimulating hormone).
Treatment & Therapy
To date, treatment largely revolves around treating the symptoms as they appear. Often a team approach is required for successful treatment throughout the individual's lifetime. The multi-disciplinary treatment team generally includes the following specialists: pediatricians, orthopedists, dentists, orthodontists, cardiologists, physical therapists, pulmonologists, and others as needed.
Often the first symptoms to appear are those that are identified during the immediate post-delivery examination, such as heart and respiratory defects (lung infections are a particular concern). These may need to be surgically corrected immediately. For genital abnormalities, surgery may also be recommended as a corrective treatment.
As affected individuals grow and develop, the treatment approach often changes to accommodate their changing needs. Therapeutic assistive devices and braces, as well as physical therapy, may aid in walking and movement. Regular dental care can adjust for crowded teeth and overgrown gums.
Prevention & Prophylaxis
As more research into each type of Robinow syndrome is performed, genetic testing is likely to become further refined for better predictive results. Specifically, since recessive-type Robinow syndrome is linked to a mutation in the ROR2 gene, it is likely that future genetic analysis will be able to better predict cases.