DNMT3A and hereditary endocrine growth disease: The occurrence of multiple affected and unaffected individuals in the same sibship, together with the combined genetic and environmental homogeneity of the Amish, permitted an in-depth investigation of the genome-wide patterns of DNA methylation associated with pathogenic variation in DNMT3A. We subsequently extended our analyses to other (non-Amish) TBRS patients harboring distinct pathogenic de novo DNMT3A variants, as well other methyltransferase-associated overgrowth and growth deficiency syndromes, defining altered epigenetic profiles as common key themes of these growth disorders.