Four recurrent autosomal dominant missense variants affecting two adjacent amino acids in the motor domain of another kinesin family protein encoded by KIF22 have been identified in several patients with spondyloepimetaphyseal dysplasia with joint laxity (SEMD; MIM 603546).(18, 19) The phenotype of all individuals harboring these variants was uniform, indicating genetic homogeneity. This evidence concerns the gene KIF22 and spondyloepimetaphyseal dysplasia, matrilin-3 type.