Identification of novel TFG mutation in HMSN-P pedigree: Emphasis on variable clinical presentations

We aimed to identify the genetic cause of neurological disease in an Iranian pedigree whose manifestations suggested hereditary motor and sensory neuropathy with proximal predominance (HMSN-P). Identification of a p.Gly269Val mutation in TFG, the known HMSN-P causative gene, provided supportive evidence. Subjective, biochemical, electrodiagnostic, and imaging data were compared with previously reported HMSN-P patients, including patients of an earlier described Iranian pedigree. Although notable clinical variability was found, comparable involvement of proximal and distal muscles was observed in both Iranian pedigrees. Interestingly, the same p.Gly269Val mutation was recently reported as cause of Charcot-Marie-Tooth disease type 2 in a Taiwanese pedigree. The likelihood that the two pedigrees with the p.Gly269Val mutation are not affected with different diseases is discussed. Identification of a second Iranian HMSN-P pedigree further confirms that HMSN-P is not confined to the Far East. Furthermore, p.Pro285Leu that has been the only TFG mutation thus far reported in HMSN-P patients is not the only mutation that can cause the disease. It is emphasized HMSN-P is a neuronopathy.