Genetic testing practices for Charcot-Marie-Tooth type 1A disease

Charcot-Marie-Tooth disease type 1A (CMT1A) is caused by a PMP22 gene duplication. CMT1A has a robust electrical phenotype that can be used to direct genetic testing. We compared specialty CMT center CMT1A diagnosis rates to those of outside physicians.

Charts were reviewed for 102 patients with CMT1A seen at a specialty CMT clinic between 2001 and 2009. Nerve conduction studies, family history, date of genetic testing, and type of genetic testing (single gene vs. panel) were collected.

Although the specialty clinic ordered more PMP22 duplication testing alone beginning at an earlier year, thereby reducing costs, both the specialty clinic and outside physicians began the decade doing panel testing and ended the decade looking at only PMP22.

Specialty centers adapt earlier to changes in testing practice than non-specialty centers. As the landscape of genetic testing changes, the algorithms for testing will also likely change.