CHAMP1 and Global developmental delay: There are only a modest number of published reports on CHAMP1 disorder, but analysis of over 1000 individuals serially ascertained for intellectual or developmental delay (IDD) identified 2 individuals with mutations (Poisson 95% CI 0.549–7.29) suggesting that as many as 1 in 500 individuals with IDD may carry mutations in this gene (Deciphering Developmental Disorders study 2015), consistent with significant under-diagnosis of this disorder.