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CHRNG gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

CHRNG gene

The CHRNG gene is responsible for producing the fetal subunit of the acetylcholine receptor, which is vital for muscle development and movement before birth.

Normal Function

The CHRNG gene provides instructions for making the gamma (γ) protein component (subunit) of the acetylcholine receptor (AChR) protein. This protein is located in the membrane of skeletal muscle cells and is critical for signaling between nerve and muscle cells, a process necessary for movement.

The AChR protein consists of five subunits assembled in the endoplasmic reticulum. The γ subunit is specific to the fetal AChR protein. At approximately the 33rd week of pregnancy, the γ subunit is replaced by the epsilon (ε) subunit (produced by the CHRNE gene) to form the adult version of the receptor.

Health Conditions Related to Genetic Changes

Multiple pterygium syndrome

At least 14 mutations in the CHRNG gene have been linked to multiple pterygium syndrome, a condition characterized by webbing of the skin (pterygium) and a lack of muscle movement (akinesia) before birth.

  • Mechanism: Mutations result in an impaired or missing γ subunit, preventing the fetal AChR protein from being properly assembled or placed in the muscle cell membrane.
  • Impact on signaling: The resulting lack of communication between nerve and muscle cells in the fetus leads to akinesia and pterygium.
  • Severity: The severity of the mutation influences the clinical outcome. Mutations that prevent all γ subunit production typically result in a lethal form of the syndrome, while those allowing some production lead to a milder form known as multiple pterygium syndrome, Escobar type.

Other Names for This Gene

  • acetylcholine gamma muscle receptor subunit
  • acetylcholine receptor subunit gamma
  • acetylcholine receptor, muscle, gamma subunit
  • ACHG_HUMAN
  • ACHRG
  • cholinergic gamma nicotinic receptor
  • cholinergic receptor, nicotinic gamma
  • cholinergic receptor, nicotinic, gamma
  • cholinergic receptor, nicotinic, gamma (muscle)
  • cholinergic receptor, nicotinic, gamma polypeptide

Frequently Asked Questions

CHRNG-related multiple pterygium syndrome is inherited in an autosomal recessive pattern. If a couple has one affected child, it means both parents are likely carriers of a CHRNG mutation. For each subsequent pregnancy, there is a 25% chance of having another child with the condition. Genetic counseling is strongly advised to discuss carrier testing and reproductive options.
The prognosis varies significantly depending on the specific mutation. Mutations that severely impair or prevent gamma subunit production often lead to a lethal form of MPS, resulting in stillbirth or death shortly after birth due to respiratory failure. Milder mutations can result in multiple pterygium syndrome, Escobar type, which involves significant physical challenges, joint contractures, and potential respiratory issues requiring extensive medical and rehabilitative care.
Prenatal ultrasound may reveal reduced fetal movement (fetal akinesia), joint contractures (fixed joints), webbing of the skin (pterygia), and sometimes polyhydramnios (excess amniotic fluid). These findings can indicate a severe neuromuscular disorder like MPS.
Diagnosis often begins with suspicious findings on prenatal ultrasound. Confirmation usually requires genetic testing, which can be performed on fetal cells obtained through amniocentesis or chorionic villus sampling (CVS) to identify mutations in the CHRNG gene.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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