The recent physical mapping of the serotonin 5-HT(7) receptor gene (HTR7) to 10q23 [67] raises the question if the inversion inv(10)(p11.2q21.2) present in our patient, which is considered a normal familial variant could have long range influence on HTR7 and susceptibility to autism in some cases. The gene discussed is HTR7; the disease is autism.