POLR2A and cardiomyopathy: Three of these have been confirmed and previously published as part of collaborative studies; a de novo p.(Gln735*) mutation in POLR2A in a patient with a novel neurodevelopmental syndrome with profound infantile-onset hypotonia [90]; a de novo p.(Tyr1224fs) mutation in KMT2E in a patient with a neurodevelopmental syndrome and epilepsy [91] and biallelic variants (p.(Gly79fs) and c.764 + 5G > A) in MCM10 causing telomere shortening and giving rise to immune dysfunction and cardiomyopathy [92].