Hypo Myelination

My best friends son who is 14 months old has just had a MRI reading of "delayed mylenation could be hypomylenation."  It is reading his mylen growth at 10 months rather than his actual age of 14.  My friends neurologist sent him for chromosomal testing and she has to wait 3 weeks to hear back.  We are both nurses in the adult world and she has been asking everyone what they think the prognosis will be.  She asked an adult neurologist that told her it is very bad and these kids always die at an early age.  Is this true, or could there be something else that it could be?  Is there any hope?  She is distraught and has not gotten back the chromosome testing yet.  Is their any news I could give her to keep her sain untell she really hears the tests come back.  Her son is delayed with his muscle strength and already is having physical therapy.  He has improved but still is not standing or trying to walk.  Any information would be greatly appreciated!