What’s in a name? Issues to consider when naming Mendelian disorders

Extraordinary advances in the field of genetics 1 have led to the identification of hundreds of new Mendelian disorders (defined here as disorders caused by pathogenic variants in a single gene) and the genes that cause them. In the last ten years, over 2500 new single-gene conditions were added to OMIM ( https://omim.org/ ), the National Institutes of Health (NIH)-funded catalog of inherited phenotypes, genes, and the relationships between them. Identification of new phenotypes and their associated genes has transformed the care of persons with Mendelian disorders through improved diagnostic testing, recurrence risk estimation, disease management, and in some cases, treatment. However, the huge number of new phenotypes has resulted in a challenge to the field—what to name these new conditions.