XRCC4 and Tremor: Neurodegenerescence, reported in two adults with XRCC4-related MPD [10], and suspected in P1 based on progressive pyramidal signs and tremor, is a main feature in Ataxia-Teleangiectasia [MIM#208900], well-reported in Cockayne [MIM#133540, MIM#216400] and Nijmegen syndromes [MIM#251260].