Will my child be born mentally retarded?

Q: I am a 30 year man married 4.5 months back to a 27 year old lady. Now my wife is pregnant. My wife's maternal uncle is mentally retarded and the behaviour of my wife's brother is also suspicious regarding his mental health. In this situation, does the ultra-sound scanning done during pregnancy helps us to detect any mental health related abnormalities in the unborn child? I have not discussed this issue with my wife as it is very sensitive. Is there any additional test available to know about the mental health of the unborn child as there is some family history of mental disability?

A:Mental retardation among male relatives of a woman is likely to be due to fragile X syndrome. If this is the diagnosis in the affected males then yourwife is at risk of being a carrier (50%), and 50% chance of not being a carrier. Please consult a geneticist.