Premutation-associated disorders in childhood and adulthood

This chapter is focused on the medical, developmental, and psychiatric aspects of premutation-associated disorders with the exception of FXTAS and FXPOI, which are covered in other chapters. A historical perspective of our understanding of premutation involvement is presented and the spectrum of premutation involvement is reviewed. Most children with the premutation do not have significant clinical involvement and most adults do not suffer from medical or psychiatric problems although when they occur it is important for the health care provider to be aware and provide treatment. Many of the neuropsychiatric and central nervous system (CNS) findings in premutation carriers are subclinical and related to the RNA toxicity that occurs with the premutation. Why some individuals with the premutation have clinical symptoms and others do not is likely related to several factors that are described in detail. Lifestyle changes to avoid toxins and promote health are also discussed.