PT - JOURNAL ARTICLE AU - M C Speer AU - J M Gilchrist AU - J M Stajich AU - P C Gaskell AU - C A Westbrook AU - S K Horrigan AU - L Bartoloni AU - L H Yamaoka AU - W K Scott AU - M A Pericak-Vance TI - Evidence for anticipation in autosomal dominant limb-girdle muscular dystrophy. AID - 10.1136/jmg.35.4.305 DP - 1998 Apr 01 TA - Journal of Medical Genetics PG - 305--308 VI - 35 IP - 4 4099 - http://jmg.bmj.com/content/35/4/305.short 4100 - http://jmg.bmj.com/content/35/4/305.full SO - J Med Genet1998 Apr 01; 35 AB - Anticipation, an increase in severity or decrease in age of onset (AO) inherent in the transmission of the disease gene from affected parent to affected child, has been increasingly described in human disease. To assess anticipation in a large kindred in which autosomal dominant limb-girdle muscular dystrophy (LGMD1A) is segregating, age of disease onset was collected from patient interviews of affected family members. A total of 25 parent-offspring pairs, in which the parents are three (3R), four (4R), or five (5R) generations removed from a common founding ancestor, were available for analysis. Life table analyses showed significant decreases in age at first reported symptoms in the offspring of the 3R (chi2=5.55, p=0.02) and 4R (chi2=7.81, p=0.005) parents. Pairwise analyses confirmed this decrease with a median decrease of 13 years in transmission to offspring from 3R parents and 18 years in transmission to offspring from 4R parents. The finding of anticipation in this pedigree suggests that the mutation in LGMD1A may be the result of the expansion of an unstable trinucleotide repeat.