DDHD2 and Spastic paraparesis: Our observed decline in motor function corroborates earlier reports associating disruption of the DDHD2 gene with classical signs of slowly progressing spastic paraparesis characterised by weakness, hyperreflexia, neuromotor dysfunction predominantly affecting the lower limbs, and ultimately aberrant gait (Blackstone, 2018; Inloes et al, 2014; Inloes et al, 2018; Joensuu et al, 2020b; Parodi et al, 2017).