Autosomal recessive multiple pterygium syndrome

Autosomal recessive multiple pterygium syndrome (also known as Escobar syndrome or Escobar multiple pterygium syndrome) is a rare genetic disorder characterized by the presence of multiple pterygia — webbing of skin across joints — along with other musculoskeletal abnormalities. The condition is present from birth and results from reduced fetal movement during development. Key clinical features include pterygia (skin webs) affecting the neck, elbows, knees, fingers, and armpits, as well as joint contractures (arthrogryposis), short stature, scoliosis or vertebral anomalies, and distinctive facial features including a flat facial profile, downslanting palpebral fissures, and micrognathia (small jaw). Affected individuals may also have cleft palate, cryptorchidism in males, and finger anomalies such as syndactyly or camptodactyly. The condition primarily affects the musculoskeletal system, but can also involve the craniofacial structures and, in some cases, the respiratory system due to restrictive chest wall abnormalities. The syndrome is caused by mutations in the CHRNG gene, which encodes the gamma subunit of the fetal acetylcholine receptor, critical for neuromuscular junction function during prenatal development. Less commonly, mutations in other genes involved in neuromuscular transmission (such as CHRNA1, CHRND, or RAPSN) have been identified. The disorder follows autosomal recessive inheritance, meaning both parents must carry a pathogenic variant for a child to be affected. There is no cure for autosomal recessive multiple pterygium syndrome. Treatment is supportive and symptomatic, focusing on orthopedic management of joint contractures and scoliosis, surgical release of pterygia when they limit mobility, and physical therapy to maximize range of motion. Craniofacial surgery may be needed for cleft palate repair. Prognosis is generally favorable for survival, distinguishing this condition from the lethal form of multiple pterygium syndrome, though the degree of physical disability varies. Long-term follow-up with a multidisciplinary team including orthopedics, genetics, and rehabilitation specialists is recommended.

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