NFIX and Malan overgrowth syndrome: We therefore examined the phenotypes of the Marshall–Smith and Malan syndromes and found that not only do most of these phenotypes exist between Neanderthals and modern humans, but their direction matches the direction expected from NFIX downregulation along the AMH lineage (18 out of the 22 Marshall–Smith phenotypes, and 8 out of the 9 Malan phenotypes, P = 6.0 × 10−4, binomial test).