 MSX1 is found to have a linkage with Witkop syndrome, also known as “tooth and nail syndrome” or “nail dysgenesis and hypodontia” since mutations in MSX1 were shown to be associated with tooth agenesis.There is a linkage found between TNS and markers surrounding the MSX1 locus and it showed that a nonsense mutation (S202X) in MSX1 cosegregated with the TNS phenotype in a three-generation family.MSX1 has been shown to interact with DLX5, CREB binding protein, Sp1 transcription factor, DLX2, TATA binding protein and Msh homeobox 2.