Chrng, encoding the γ subunit of the embryonal acetylcholine receptor, is crucial for normal neuromuscular function. The nicotinic acetylcholine receptor at the neuromuscular junction is involved in neuromuscular signal transmission, and Chrng's role in this process is essential for proper muscle movement and development [2].

Mutations in Chrng cause autosomal recessive multiple pterygium syndrome (MPS), with a distinctive phenotype of multiple congenital contractures, pterygium, and facial dysmorphism. Postnatal abnormalities at the neuromuscular junction are seen in affected patients' muscle biopsies. Whole-body magnetic resonance imaging shows marked muscle bulk reduction, mainly in spinal erector and gluteus maximus muscles, with fatty infiltration in deep paravertebral and distal lower limb muscles [1]. Germline mutations in Chrng can lead to non-lethal Escobar variant (EVMPS) or lethal form (LMPS) of MPS, and also present with fetal akinesia deformation sequence (FADS) without pterygia. The mutation spectrum is similar in EVMPS and LMPS/FADS kindreds, and there is interfamilial variability in the severity of the phenotype [3,4].

In conclusion, Chrng is vital for normal neuromuscular function. Its mutations are associated with multiple pterygium syndrome, highlighting its significance in understanding the pathophysiology of this disorder. The study of Chrng-related mutations helps in better defining the phenotypic spectrum of the disease, which may aid in differentiating it from other similar conditions and potentially in developing targeted therapies [1,3,4].