"having or being a chromosome number that is not of the usual number, that is, greater or lesser than 46"
XYY -- Stereotype of the Karyotype by Edward R. Friedlander, M.D., a pathologist from Kansas who claims to have the aneuploidy XYY, yet by his own admission, has never been tested.
Stefan's XXYY Connection Page
Klinefelter Syndrome and the XXYY variant
XXYY Parent Network
The XXYY parent network has been established for parents of sons with the karyotype 48,XXYY and gives them a place to talk with each other about issues specific to this karyotype. This is a moderated list and by subscription ONLY to those parents who have an XXYY son. Click here to subscribe.
Stefan's XXXY Connection Page.
Unique Rare Chromosome Disorder Support Group
Androgen Insensitivity Syndrome Support Group (AISSG)
Contact a Family, U.K.
Helping Families who care for children with any disability or special need
A very good overview of Chromosomal Deletions, Additions, Inversions, Translocations and Rings CDO.
Other Chromosomal Variations
Fragile X, from the U.S. National Institute of Child Health and Human Development (NICHD).
Support Organization For Trisomy 13/18 and related disorders
U.K.: S.O.F.T. U.S.: S.O.F.T.
European chromosome 11q network 11Q
Booklet from The Turner Center:
Turner Syndrome Society of Canada
The Turner Syndrome Society of the United States
The Chromosome 18 Registry and Research Society