Science, Vol 246, Issue 4935, 1298-1300
Copyright © 1989 by American Association for the Advancement of Science
A new DNA marker tightly linked to the fragile X locus (FRAXA)
GK Suthers,
DF Callen,
VJ Hyland,
HM Kozman,
E Baker,
H Eyre,
PS Harper,
SH Roberts,
MC Hors-Cayla,
KE Davies,
and
al. et
Department of Histopathology, Adelaide Children's Hospital, Australia.
The fragile X syndrome is the most common cause of familial mental retardation. Genetic counseling and gene isolation are hampered by a lack of DNA markers close to the disease locus. Two somatic cell hybrids that each contain a human X chromosome with a breakpoint close to the fragile X locus have been characterized. A new DNA marker (DXS296) lies between the chromosome breakpoints and is the closest marker to the fragile X locus yet reported. The Hunter syndrome gene, which causes iduronate sulfatase deficiency, is located at the X chromosome breakpoint that is distal to this new marker, thus localizing the Hunter gene distal to the fragile X locus.
