Not Just Neuropathy: Implications for Workup and Management of Additional Genetic Diagnoses with Charcot-Marie-Tooth Disease

Topic:

Clinical Management

Poster Number: 340 T

Author(s):

Allison Wheeler, MS, CGC, Children's Hospital Colorado, Melissa Gibbons, MS, Children's Hospital Colorado, Meghan Moore Burk, PhD, PT, DPT, Children's Hospital Colorado, Carolyn Kelley, PT, DPT, Children's Hospital Colorado, Caitlyn Silver, MS, OTR/L, Children's Hospital Colorado, Ella Harrington, OTD, Children's Hospital Colorado, Hattie Foster, RN, Children's Hospital Colorado, Kelli Johnson, CPNP, Children's Hospital Colorado, Ava Baumann, BA, Children's Hospital Colorado, Margaret Siobhan Murphy-Zane, MD, Children's Hospital Colorado, Susan Apkon, Children’s Hospital Colorado, Michele Yang, MD, Children's Hospital Colorado

Background: Genetic conditions are often considered “individually rare, collectively common” reflecting that the statistical chance to have a single genetic diagnosis is low. The appropriate care of genetic disorders, such as Charcot-Marie-Tooth (CMT), requires recognition and appropriate genetic workup of atypical features. Patients from our multidisciplinary CMT clinic were reviewed to identify those with additional genetic diagnostic workups with a goal to describe the workup and identify the appropriate medical home for these patients when a dual genetic diagnosis was identified.

Results: We present a series of eleven patients with CMT1A and additional genetic workups. Eight patients received a second genetic diagnosis in addition to CMT, representing 7.69% of our CMT clinic. CMT1A was incidentally diagnosed in six patients during genetic testing workup for unrelated symptoms. Five patients presented for CMT evaluation/care with an additional genetic diagnosis already identified by other specialties, most often by Genetics/Metabolism. Additional genetic workup for three sibling patients was performed by Endocrinology, for one patient by the CMT team, and one patient was referred back to Genetics by the CMT team for continued workup. Dual genetic diagnoses include Trisomy 21 (one patient), Rubenstein-Taybi syndrome (one patient), Potocki-Lupski syndrome (one patient), partial RAI1 duplication (one patient), Complete Androgen Insensitivity syndrome (three patients), and Klinefelter syndrome (one patient).

Discussion: Recognition of dysmorphic features, neurodevelopmental disorders, or non-neurological features not within the scope of a CMT diagnosis is key to identifying when additional genetic workup is indicated. When dual genetic diagnoses are made, patient needs should be individually considered to establish an appropriate medical home, promote collaboration across multiple specialties, and assess how features of additional diagnoses may impact standard CMT evaluations. Additionally, dual genetic diagnoses may have treatment implications as genetically-based therapies expand.