BSCL2 and motor neuron disorder: Loss-of-function mutations in BSCL2 lead to Berardinelli–Seip congenital lipodystrophy (MIM# 269700), whereas gain-of-toxic-function mutations in BSCL2 cause a motor neuron disease (MIM# 600794) (Ito and Suzuki, 2009; Magré et al.