As reported by Loo et al. [15], rare haplotypes around rs1021261 in LUZP2 gene were associated with the higher intelligence in an ancestrally homogeneous family sample of individuals with at least one child affected by attention-deficit hyperactivity disorder (ADHD), while in our study the rare homozygous genotype was significantly more common in the lower quartile of the MoCA distribution. Here, LUZP2 is linked to attention deficit-hyperactivity disorder.