the incidence of a fragile x-chromosome ( fra ( x ) ) was found to be 4.7 % in an unselected group of 42 patients , 50 % among 10 probands in which pedigree data were suggestive of x-linked mr diagnosis , and 75 % in the group of 15 patients selected for phenotype characteristic of the fragile x syndrome .
C1136249
x-linked mr
C0016667
fragile x syndrome