This is a very rare genetic condition affecting several parts of the body presenting symptoms such as a small sized head, distinct facial features, unusually short digits, seizures and intellectual disability. The features associated with this disease can also deteriorate over time. Around one-third of the people with this syndrome may never speak. They also exhibit the early skin wrinkling because of the lack of fat layer under the skin. As this is a rare condition, only around 75 cases have been reported in the medical literature.
Causes
This disease develops because of a genetic mutation identified in the SMARCA2 gene which is essential for the production of a subunit of a group of protein complexes called SWI/SNF complexes. These are important for the regulation of the genetic activity through a process known as chromatin remodeling. This process is one of the manners in which the gene expression is regulated during the development. The genetic mutation results in the production of an altered protein that affects the normal function of the SWI/SNF complexes. As the result, the SWI/SNF complexes cannot participate in the chromatin remodeling. This can affect the activity of several genes and results in the development of the diverse signs and symptoms of the syndrome. All the cases develop because of de novo (new) genetic mutation that occurs during the formation of the reproductive cells or during the early embryonic development.
Symptoms
This condition is mostly characterized by the intellectual disability, short stature, seizures, distinctive facial features, short digits and prominent joints of the fingers and toes. The intellectual disability can be severe in most of the cases although some may experience mild or moderate disability. Around 30% of the affected individuals may never develop speech. They may also exhibit temper tantrums or periods of aggression with some presenting autism spectrum disorder. Epilepsy can affect around 2 to 3 of the cases and the type of seizure can vary. The distinctive facial features include the prominent eyelashes, a triangular-shaped face, thick nostrils, upturned lip, a nose with a broad base and a wide mouth. As these children continue to grow, they present the sagging and wrinkling of the skin particularly below the eyes and at the cheeks when smiling. The sparse scalp hair is also one of the major features of the condition.
Diagnosis
The diagnosis is based on the identification of the features, the symptoms and with various specialized tests. The genetic testing can also help confirm the diagnosis by detecting the mutation responsible for developing this condition.
Treatment
There is no cure for the disease but the treatment can help with the management of the symptoms. Based on the symptoms, the treatment can consist of medications, physical therapy, speech therapy and occupational therapy.
References
https://www.thinkgenetic.com/diseases/nicolaides-baraitser-syndrome-8801/diagnosis-testing/3738
https://rarediseases.info.nih.gov/diseases/270/nicolaides-baraitser-syndrome
https://ghr.nlm.nih.gov/condition/nicolaides-baraitser-syndrome#inheritance