Evidence for Cognitive Deficits in X-Linked Charcot-Marie-Tooth Disease

Abstract

Objective: X-linked Charcot-Marie-Tooth disease (CMTX) is an hereditary neuropathy caused by mutations in GJB1 coding for connexin-32, found in Schwann cells, but also expressed in oligodendrocytes. Reports have identified CNS involvement in CMTX, but no systematic study of cognitive function has been published.

Methods: We assessed 24 CMTX patients (13 males; 9GJB1 mutations) with a comprehensive neuropsychological battery, including tests of memory, language, and executive functions.

Results: No differences in cognitive performance were observed between males and females. A case-by-case investigation revealed selective deficits in individual patients. One subgroup (29%) demonstrated executive abnormalities; and a non-overlapping subgroup (29%), prominent reading (decoding) abnormalities.

Conclusions: The present data provide evidence for cognitive deficits in CMTX. Emerging neuropsychological patterns are also discussed.

Keywords: CNS involvement; Cognitive flexibility; Cognitive impairment; Connexin-32; Decoding; Executive functions; GJB1; Reading fluency.