From: Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: a case-control study
rs10235235 genotype
Cases
Age at menarche (years)
P trend
Controls
AA
22,954
12.83
23,383
12.95
AG
4,312
4,627
13.02
GG
207
248
13.05
Total
27,473
0.97
28,258
12.96
0.005