* SAS code to fit Mut. Freq. data ;
 options linesize=70;

 data MutFrq;
 input gender $ age y @@;
 agebar =  5.8344;
 x = age - agebar;
 cards;
  f  0.75 0.3  f  13.2  4.0  m  4.2  2.5
  f  0.83 0.4  f  13.9  1.2  m  4.4  2.6
  f  1.0  0.4  f  13.9  1.2  m  4.7  0.7
  f  1.2 0.77  f  15.2  4.3  m  5.16  0.7
  f  2.0  2.0  m   5.2  2.2
  f  2.0  2.9  m  0.08  1.3  m  6.4  5.4
  f  3.1  0.7  m   0.2  0.3  m  8.1  4.1
  f  3.2  1.0  m  0.75  0.5  m  8.2  0.81
  f  3.2  1.8  m  0.75  1.9  m  8.7  0.5
  f  4.0 0.45  m   0.8  1.1  m  8.9  2.2
  f  5.0  0.4  m   1.0  0.32 m  9.7  2.1
  f  6.5  8.0  m   1.0  1.3  m 10.0  2.3
  f  7.5  1.4  m   1.0  4.4  m 10.7  2.0
  f  7.7  8.7  m   1.3  3.1  m 12.0  5.5
  f  9.0  9.0  m   1.4  2.2  m 12.5  4.0
  f 10.9  0.8  m   1.5  0.85 m 13.1  0.2
  f 11.0  1.9  m   1.7  1.7  m 13.2  7.0
;

 proc genmod;
    class gender;
    model y = x gender / dist=gamma
                         link=log
                         type3;
 contrast 'f vs. m' gender 1 -1;

 run;