Aslaam Aleakum,
Fragile X is not necessarily a severe disability. You can red and write obviously so you are not severely affected the way some people are, alhumdulillah. Since you have an education and also very good reasoning ability you can work and support a wife, yes? And while you will pass on the gene to your daughters it will not affect them. (they will be carriers but not disabled) However the will have to go through genetic counseling when/if they have children, particularly sons.
While I usually hesitate to use Wiki as a source I am fairly versed on this genetic anomaly and found the info to be accurate.
http://en.wikipedia.org/wiki/Fragile_X_syndrome
Of course this is strictly my opinion from a medical/psychological standpoint and I am not an Islamic scholar. But given that Islam requires a male to be able to support his wife, both physically and psychologically, I don't see any reason why you couldn't marry. May Allah swt bless you with a pious wife and may you spend eternity in Jennah, ameen.