Ascertainment biases in the markers selected on the array or the reference population used in imputation may lead to lower coverage, as commonly observed in African ancestry populations. However, increasing coverage on the array (as we did with the African (YRI) booster panel) and diverse reference panels for imputation, helps mitigate this issue. Another limitation of these approaches over sequencing, is the identification of de novo mutations. These mutations, however, account for a small fraction of both rare and common neurodevelopmental diseases and require pedigrees for analysis [66].
