Dysmorphology

• Based on level D evidence (expert opinion, case reports, reasoning from first principles), dysmorphology is an art and science of precise clinical reasoning that addresses the variation of physical features. (7)(16) • Based on level D evidence (expert opinion, case reports, reasoning from first principles), the family history is an important source of genetic information. Recognizable inheritance patterns include autosomal dominant, autosomal recessive, X-linked, and mitochondrial genomic. (11) • Based on level D evidence (expert opinion, case reports, reasoning from first principles), it is useful to consider the different types of genetic and nongenetic changes that are associated with physical changes when constructing genetic differential diagnoses, which ultimately determines the optimal genetic testing strategy. • Based on level D evidence (expert opinion, case reports, reasoning from first principles), resources available to pediatricians include the Elements of Morphology, the Handbook of Physical Measurements, Smith's Recognizable Patterns of Human Malformation, the Online Mendelian Inheritance in Man® database, and the London Dysmorphology database (available through the Face2Gene smartphone application). (2)(8)(17)(18) (27) • Based on level D evidence (expert opinion, case reports, reasoning from first principles), it is important to ask about and learn of any previous genetic testing before ordering a genetic test. • Based on level D evidence (expert opinion, case reports, reasoning from first principles), it is important to be precise and careful in word choice when discussing genetic testing results and genetic diagnoses.