Heterogeneity in genetic disorders that affect the orofacies.

The diagnosis of genetic disorders is complicated by multiple genetic causes for the same or similar disorders, phenotypic similarities of different disorders, and environmental disorders that resemble genetic ones. The clinical geneticist is well versed in identifying genetic heterogeneity, and the extent of the clinical heterogeneity and phenocopies for diseases with which he or she deals regularly. Nonetheless, the expertise of clinical geneticists form other specialties of medicine or dentistry may be useful in documenting heterogeneity that otherwise may be overlooked. The examples presented here illustrate that heterogeneity is as important to the dentist who practices clinical genetics as it is to the physician-clinical geneticist, and that a consultation with a properly trained dentist may be a useful part of a protocol for the genetic evaluation.