Indeed, rare variants of ARSA [171,172], CSF1R [37,173,174], TREM2 [156,163,175,176,177], TYROBP [178], NOTCH3 [179] and CYP27A1 [180] have been identified as potential genetic causes of patients with clinical features of FTD. This evidence concerns the gene CYP27A1 and frontotemporal dementia.