Germaine L. Defendi

Editor's Note: The Case Challenge series includes difficult-to-diagnose conditions, some of which are not frequently encountered by most clinicians, but are nonetheless important to accurately recognize. Test your diagnostic and treatment skills using the following patient scenario and corresponding questions.

Authors and Disclosures Author(s) Stephen L. Nelson, Jr, MD, PhD Chief of Pediatric Neurology; Professor of Pediatrics, Neurology, Neurosurgery, and Psychiatry; Epileptologist; Medical Director, Tulane Center for Autism and Related Disorders; Co-director, Developmental Neurogenetics Center, Tulane University School of Medicine, New Orleans, Louisiana Disclosure: Stephen L.

The holiday season is a time when many people reflect on family, so it seems appropriate to consider some significant medical conditions that are passed on within families. Many genetic disorders and conditions can be traced through ancestry or ethnicity to parents and grandparents. Among the more common inherited genetic conditions, cystic fibrosis and sickle cell disease are inherited in an autosomal recessive fashion, whereas Huntington disease is passed on in an autosomal dominant manner.