Her brother, patient P5 (Figure 1B), also carries the CDKL1 c.617C>T variant and presented with scoliosis, positive thumb sign, greater than 90° extension of the fifth digit, reduced upper segment/lower segment ratio, increased arm/height ratio (dolichostenomelia), and dural ectasia at the age of 23 years and at his most recent clinical examination at the age of 34 years. Here, CDKL1 is linked to scoliosis.