 As well as autosomes, human neocentromeres have also been observed in sex chromosomes, and correlate with some sex-linked diseases.In 1999, analysis of a neocentromere in the Y chromosome with a constriction site in the amniocytes of a 38-year-old woman, and in her husband and brother-in-law served as experimental evidence that neocentromeres can be stably transmitted through meiosis into the next generation.Not only is the neocentromere viable on a chromosome, it is also sufficient for allowing proper male sex determination.