“Children with Moebius syndrome often have trouble moving their faces.  They may also have trouble feeding. Some children with Moebius syndrome also have abnormal development in the limbs or chest muscles.  Moebius syndrome is not progressive, meaning it does not get worse over time.  Moebius syndrome is very rare. The exact incidence is unknown, but some estimates are 2 to 20 cases per million births.”

Cleveland Clinic (https://my.clevelandclinic.org/health/articles/6064-moebius-syndrome)