The condition associated with variants of POLR2A ranges from mild to severe. Of the 28 patients that have been identified in the current literature, the following phenotypes have been reported in at least 25% of case reports: developmental delay, hypotonia, visual impairment (strabismus, delayed visual maturity, decreased vision, etc.), gastroesophageal reflux, disturbed sleep, recurrent respiratory tract infections, seizures, abnormal MRI (hypoplasia/agenesis of corpus callosum, ventriculomegaly, delayed myelination, etc.), failure to thrive, autism spectrum disorder/autistic behaviours, microcephaly, high forehead, decreased endurance, frog position in infancy, feeding difficulties, hypertelorism, intellectual disability, abnormal movements, and ataxia.
The following phenotypes have been reported in less than 25% of cases: high palate, brachyplagiocephaly, muscle atrophy, short stature, hernia, pectus excavatum, teeth misalignment, hearing impairment, developmental regression, dystonia, head and neck arching in infancy, hypermobility, skeletal anomaly, and constipation.
POLR2A