Mutation frequency within genes: The frequency of different molecular defects is not the same for every gene and every disorder. Cooper, in Emery and Rimoin's Principles and Practice of Medical Genetics and Genomics (Seventh Edition), 2019 6.3.19 Frequency of Disease-Producing Variants This regime also gave a marked reduction in mutation frequency as compared with a more acute exposure ( Table XI and Table XII) except in second litters from older females (see below). The length of time over which the 400‐R exposure was distributed in the 8 × 50‐R experiment was the same as when the same exposure was given at an intensity of 0.8 R/min. Russell (1968a) considered that the low mutation frequencies obtained with a single or repeated exposures to 50 R confirmed the earlier prediction ( Russell et al, 1958a) that lower doses of acute x‐irradiation would permit repair of a higher proportion of mutations than high doses, thus giving rise to a “dose effect” corresponding to the well‐established dose‐rate effect.

Fractionation of the 400‐R exposure into eight separate exposures at 75‐minute intervals also led to a significant reduction in mutation frequency ( Russell, 1968a), but two fractions of 200 R separated by 24 hours gave a very similar frequency to that of the single exposure, as Table XI shows. 6), so that at 50 R the mutation frequency is only one‐third of expectation on the basis of linearity with the 400‐R figure ( Russell, 1968a). The dose‐response curve seems to be concave ( Fig. The mutation frequency of 22 × 10 −5/locus obtained after 400 R of acute x‐irradiation ( Table XI) is twice that expected from the same exposure if received by spermatogonia (about 11 × 10 −5/locus).

Angband mutation flatulence