A newborn with unusual morphology: some practical aspects.

Newborns with an unusual phenotype with or without malformations are common in the practice of every paediatrician. Determining whether the phenotype is a variation of normal or should be considered abnormal and, if the latter, also finding the cause can be extremely difficult. Here the main steps that should be followed in the diagnostic procedures are discussed. A careful family history and detailed physical examination remain the hallmarks of the investigations in all newborns. Very frequently clinical photographs will facilitate discussing patients with colleagues. Additional investigations usually include radiological examinations of all body parts that show abnormalities, and screening of the heart, kidneys, eyes and hearing. The studies with the highest yield are cytogenetic analyses which nowadays often involve microarray assays. In the near future, total exome sequencing will be available for diagnostic purposes which will have a major impact on the diagnostic process.