ABSTRACT
The scientific basis for anticipation was called into question when Penrose convincingly argued that the clinical observations consistent with anticipation reported by Fleischer and Bell were likely to be due to biases of ascertainment and that there was no biological basis for anticipation in myotonic dystrophy or other disorders. Investigators in Sweden have studied families with unipolar depression (subjects experience recurrent major depression only) and bipolar disorder and report the presence of anticipation in both family sets. The modern study of anticipation in psychiatric diseases began shortly after the initial association of anticipation and triplet repeats, with an analysis of 34 bipolar pedigrees ascertained for a genetic linkage study. The presence of anticipation in psychiatric disorders is clearly of relevance to the investigator, who now has one more clue in trying to find the genetic mechanisms of these elusive disorders.
