Abnormalities of human sex chromosomes - VI. Monozygotic twins with the complement 48,XXXY Article

cited authors

  • Simpson, JL; Morillo-Cucci, G; Horwith, M; Stiefel, FH; Feldman, F; German, J

fiu authors


  • The cytogenetic study of a pair of identical, mentally-retarded twins with the chromosome complement 48,XXXY is reported, along with extensive clinical and endocrinological studies of one twin. The genetic and clinical features of 30 reported 48,XXXY individuals were summarized and compared to those of 47,XXY and 49,XXXXY individuals. For 47,XXY the mean maternal age clearly is increased; for 48,XXXY it appears definitely but only slightly increased; and for 49,XXXXY it may not be increased at all. Developmental defects, similar in type, appear to be progressively more marked when an additional 1, 2, or 3 X chromosomes are added to the normal male chromosome complement. 47,XXY individuals may be either normal in intelligence or mentally retarded, whereas severe mental retardation has been present in all those with the complements 48,XXXY and 49,XXXXY. The interesting suggestion of increased twining associated with poly-X male complements is noted. © 1974 Springer-Verlag.

publication date

  • December 1, 1974

Digital Object Identifier (DOI)

start page

  • 301

end page

  • 308


  • 21


  • 4