GIGYF1 and Global developmental delay: We found that 2 of the 5 siblings in SPARK had parent-reported language and/or motor developmental delay, which showed a marginally significantly higher rate (40% versus 8%, P = 0.053) relative to parent reports of language and motor developmental delay in siblings without ASD and GIGYF1 LGD variants (Figure 2D), although the sample size was too small to draw a conclusion.