TBX5 and Holt-Oram syndrome: TBX5 participates in transcriptional regulatory cascades and its pathogenic mutations, located within the DNA binding T-box domain, manifest in a rare condition called Holt-Oram syndrome with deformity of upper limbs, carpal tunnel syndrome, and cardiac anomalies.27 We suggest that TBX5 may cause demyelinating neuropathy affecting predominantly the motor nerves.