CHRNG-associated hypo-akinesia disorder of prenatal onset
A spectrum of presentations resulting from biallelic protein-altering variation in CHRNG. Inactivation of the receptor during early development leads to prenatal hypo-akinesia; subsequent phenotypes are a consequence of this hypo-akinesia and are thought to be dependent upon timing and severity of the anomaly at the neuromuscular junction. A range of phenotypes varying in severity (including both lethal and non-lethal presentations) have been reported, but typically include joint contractures, pterygia, dysmorphic features, vertebral and thoracic anomalies, and additional variable abnormalities. There are no clear genotype-phenotype correlations between the lethal and non-lethal presentations of this spectrum; both inter- and intra-familial variability have been reported, with the same variants being observed in both lethal and non-lethal cases.