TY - JOUR T1 - Segregation analysis of peripheral neurofibromatosis (NF1). JF - Journal of Medical Genetics JO - J Med Genet SP - 307 LP - 310 DO - 10.1136/jmg.27.5.307 VL - 27 IS - 5 AU - M Littler AU - N E Morton Y1 - 1990/05/01 UR - http://jmg.bmj.com/content/27/5/307.abstract N2 - Four studies of NF1 support a prevalence of 0.0003 and a carrier incidence at birth of 0.0004. The gene frequency (q) is therefore 0.0002, and the proportion of cases owing to fresh mutation is 0.56. The mutation rate (xq) is 10(-4), an unusually high value suggestive of a large gene. Penetrance among subjects examined is virtually complete, and there is no evidence of phenocopies or somatic mutations. ER -