Maternal meiosis II nondisjunction in a case of 47,XXY testicular feminization.

An 11-year-old patient with incomplete testicular feminization and a 47,XXY karyotype is described. The patient had female external genitalia, clitoromegaly, and some features of Klinefelter's syndrome, including speech delay and delayed intellectual development. DNA analysis using X chromosomal DNA sequences suggest that the supernumerary X chromosome in the patient resulted from maternal nondisjunction during meiosis II. The M II error thereby provides the basis for homozygosity of a mutation in the androgen receptor locus.