Genetic testing and genome sequencing have opened up the possibility to clinicians and families to treat diseases, syndromes, and malformations earlier and provide therapeutic interventions.The guest editors seek to provide a basic overview of the topic for the neonatologist/perinatologist. Articles addres dysmorphology, syndromes in the infant, skeletal dysplasias, limb malformations, craniofacial anomolies, GI/liver disease, disorders of sexual develoment, brain defects, inborn errors of metabolism, and congenital heart disease.