Case Series of Three Children with SH3TC2-Related Hereditary Sensorimotor Neuropathy


Clinical Management

Poster Number: 7


Meghan Moore Burk, PT, DPT, Children's Hospital Colorado, Carolyn Kelley, DPT, Colorado Children's Hospital, Susan Apkon, MD, Children's Hospital Colorado, Michele Yang, MD, Children's Hospital Colorado, Margaret Murphy-Zane, MD, Children's Hospital Colorado, Alison Ballard, NP, Children's Hospital Colorado, Hattie Foster, RN, Children's Hospital Colorado, Caitlyn Silver, OT, Children's Hospital Colorado, Melissa Gibbons, GC, Children's Hospital Colorado

Background: Mutations in SH3TC2 result in a sensorimotor neuropathy associated with severe scoliosis, other orthopedic deformities, cranial nerve involvement, and respiratory problems presenting in the first decade of life. This rare subtype of Charcot Marie Tooth (CMT) is referred to as CMT4C. We present a single institutional experience of pre- and post-operative management and outcomes of 3 children who underwent surgical procedures by the age of 11. This case series describes their presentation, surgical history, and functional outcomes. Results: All three children have genetically confirmed SH3TC2 mutations with diagnoses at age 10.7, 8.7, and 5.8 years. At time of diagnosis, the referring symptom was for significant balance deficits with contributions from advanced orthopedic deformities. Two children had electrophysiologic testing showing a demyelinating polyneuropathy. Two have a history of gait abnormalities noted before 12 months of age. Additionally, two children have a history of aspiration with dysphagia and abnormal sleep studies. All three children have had orthopedic complications. Child 1 had progressive cavovarus foot deformities impacting ambulation, requiring surgical correction of both feet within 6 months of diagnosis. Child 2 had surgical correct of left foot due to cavovarus deformity within 2 years of diagnosis. Child 2 and 3 had early scoliosis noted at age 4 with rapid progression. Child 2 had progression of scoliosis from underwent posterior spinal fusion 2.8 years after diagnosis. Child 3 had progression of scoliosis and underwent MAGEC rods 1.5 years after diagnosis. Case 3 had hip dysplasia and underwent bilateral proximal femur varus osteotomy with internal fixation. Post-operative rehabilitation was recommended for all children. From a functional standpoint, all three had progressively slower timed function tests, gait changes, and significant balance deficits noted on the CMT Pediatric Scale Balance subscale over time regardless of surgical intervention. Fine motor function declined overtime based on grip strength, the Function Dexterity, and 9 Hole Peg test. Conclusions: Based on our experience, children with CMT4C present with rapidly progressing orthopedic deficits in spine, hips, and feet. After orthopedic surgeries, they continued to have slower timed tests and impaired balance. Children with CMT4C may present with early symptoms within the first year of life including gross motor delays and swallowing dysfunction.