TY - JOUR T1 - A genetic study of von Recklinghausen neurofibromatosis in south east Wales. I. Prevalence, fitness, mutation rate, and effect of parental transmission on severity. JF - Journal of Medical Genetics JO - J Med Genet SP - 704 LP - 711 DO - 10.1136/jmg.26.11.704 VL - 26 IS - 11 AU - S M Huson AU - D A Compston AU - P Clark AU - P S Harper Y1 - 1989/11/01 UR - http://jmg.bmj.com/content/26/11/704.abstract N2 - A population based study of von Recklinghausen neurofibromatosis in south east Wales (population 668,100) identified 69 families with 135 affected members (prevalence 1/4950 of the population). In these families penetrance of the NF-1 gene was 100% by the age of five years. The genetic fitness of NF-1 sufferers was found to be reduced to 0.47, the effect being more marked in males than females (f = 0.31 and 0.60, respectively). Forty-one of 135 cases were judged to represent new disease mutations and the mutation rate was estimated to lie between 3.1 x 10(-5) and 10.4 x 10(-5). A parental age effect for new mutations was not found, nor was a maternal effect on disease severity. ER -