The second region associated with height spans FGF16, ATRX and MAGT1. The lead SNP (rs182838724, joint P-value = 2.71×10−9, MAF = 0.30) is intronic within ATRX, a gene associated with the X-linked alpha thalassaemia mental retardation syndrome (ATR-X), a rare condition manifesting itself as profound developmental delay often accompanied by several other distinct characteristics including skeletal abnormalities in 90% and short stature in two thirds of the affected individuals [15]. Here, MAGT1 is linked to Global developmental delay.