This patient with FTDP-17 caused by the IVS10+16C>T splice site mutation in the MAPT gene initially presented in his mid-40s with subtle parkinsonism and essentially intact cognition, an age at onset and clinical phenotype apparently different from that of his affected progenitors, who had cognitive problems of later onset, with or without parkinsonism, indicating intrafamilial clinical heterogeneity.3 Over time, he developed a typical PSP motor phenotype, which has been previously reported with this MAPT mutation,7,8 developing in the context of a dementing disorder in one patient.8 PSP phenotype has also been observed with other MAPT mutations, including R5L, N279K, ΔN296, G303V, and S305S.1,2 Respiratory failure as a feature of FTDP-17 has also been reported, in a highly inbred family from the traveling community in Yorkshire, England, with a recessively-inherited MAPT mutation (S352L): two individuals presented with stridor, dyspnea, aspiration pneumonia, and respiratory failure, and one had additional mild parkinsonism and eye-movement signs.9
SCTx holds great hope for the treatment of many disorders, including chronic neurological conditions, such as multiple sclerosis and motor neuron disease.4 It is an established treatment for a variety of hematological disorders. However, research into the neurological applications of SCTx is still at a relatively early, experimental, stage, with no high-quality evidence of clinical efficacy yet available. Nonetheless, commercial clinics providing SCTx have opened, and a phenomenon of “stem-cell tourism”5 has developed as patients desperately searching for treatment patronize these units.
Although idiopathic Parkinson’s disease may be deemed a good candidate for neurotransplantation because the pathology is site-specific, with single cell-type loss,4 this may not be true of FTDP-17. Previous reports of FTDP-17 patients undergoing SCTx have not been identified. Sadly, this patient’s experience of progressive parkinsonism has provided no evidence for benefit of SCTx in FTDP-17.