Which are the causes of Autosomal recessive multiple pterygium syndrome / Escobar syndrome?

Autosomal recessive multiple pterygium syndrome, also known as Escobar syndrome, is a rare genetic disorder characterized by multiple joint contractures (pterygia), webbing of the skin (cutaneous syndactyly), and other distinctive features. This syndrome is caused by mutations in the CHRNG gene, which is located on chromosome 2.

The CHRNG gene provides instructions for making a protein called the gamma subunit of the acetylcholine receptor. This receptor is involved in transmitting signals between nerve cells and muscle cells, allowing for normal muscle movement. Mutations in the CHRNG gene disrupt the normal function of the acetylcholine receptor, leading to the characteristic features of autosomal recessive multiple pterygium syndrome.

Autosomal recessive inheritance means that an individual must inherit two copies of the mutated gene (one from each parent) in order to develop the syndrome. If both parents carry one copy of the mutated gene, they have a 25% chance with each pregnancy of having a child with the syndrome.

Signs and symptoms of autosomal recessive multiple pterygium syndrome can vary widely among affected individuals. The most common features include:

• Multiple joint contractures: This refers to the abnormal bending or fixation of joints, which can restrict movement and cause joint deformities.


• Cutaneous syndactyly: This is the fusion of the skin between two or more fingers or toes, giving the appearance of webbed hands or feet.


• Facial abnormalities: These may include a small mouth, a short or upturned nose, a small chin, and a high-arched palate.


• Respiratory difficulties: Some individuals may have breathing problems due to the involvement of the muscles used for breathing.


• Other features: Additional features can include scoliosis (curvature of the spine), clubfoot, underdeveloped muscles, and abnormalities of the genitalia.

Diagnosis of autosomal recessive multiple pterygium syndrome is based on the presence of characteristic signs and symptoms. Genetic testing can confirm the diagnosis by identifying mutations in the CHRNG gene.

Treatment for autosomal recessive multiple pterygium syndrome is focused on managing the symptoms and improving quality of life. This may involve physical therapy to improve joint mobility, orthopedic interventions to correct joint deformities, and surgical procedures to release contractures or correct other abnormalities. Supportive care from a multidisciplinary team of healthcare professionals is essential to address the specific needs of each individual.

In conclusion, autosomal recessive multiple pterygium syndrome, or Escobar syndrome, is a rare genetic disorder caused by mutations in the CHRNG gene. This syndrome is characterized by multiple joint contractures, cutaneous syndactyly, and other distinctive features. Diagnosis is based on clinical findings and confirmed through genetic testing. Treatment focuses on managing symptoms and improving quality of life. Ongoing research is being conducted to further understand the underlying mechanisms of this syndrome and develop potential therapies.