The worst symptoms health is heart disease and in some cases also of 22q is the sequence Di george, which affects the immune system, not all the people who have 22q are Di George, and not all who have Di George are 22q (that is to say the deletion of chromosome 22.
These two diseases are the ones that have caused the death of some small.
Another disease spoken of in the literature is a percentage of people who may suffer from psychosis, even schizophrenia, although it is not clear if it is because of brain structure or by their family and social environment.
And finally, in the cognitive part is that there is a delay, as in some cases it is incapacitating. Personally I think that this can be avoided with early stimulation and providing an atmosphere of tranquility and affection.