"statistically" meaning any individual child could have any IQ, and genes are only one factor out of many, but when you measure the entire group the graph of IQs is going to look different.
A comparison would be like, filtering IVF in 50 couples based on X/Y chromosomes and measuring height. That filter doesn't decide how tall a child will be, but it does shift the average. The filter would cause a height change, on a statistical basis.