Two genes, PAK2 and FANCD2 differentially expressed in TD vs. ASD, three genes, DNMT3A, FOXP1, and GTF2I differentially expressed in TD vs. FXSA, and seven genes, including PAK2, RASSF9, ITIH1, ASH1L, SND1, AHNAK, and MINK1, differentially expressed in ASD vs. FXSA, were among those listed in the SFARI Gene database. The gene discussed is PAK2; the disease is thanatophoric dysplasia.