as a genetic entity is an evolving process, the naming of a disorder in OMIM may change over time, but a MIM number remains a stable identifier. OMIM splits phenotypes by their molecular basis. Individual members of a genetically heterogeneous phenotype are grouped into Phenotypic Series. Discussion of genetic heterogeneity and the overarching phenotype description is found in the lowest numbered member of the series, and each series has a unique PS number. Clinical synopses are specific to the patients sharing the same altered gene, and their clinical synopses can be viewed side-by-side in the Phenotypic Series.
