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Updated: Aug 19, 2026

Systems Biology of Metabolic Regulation by Estrogen Receptor Signaling in Breast Cancer
Published on: March 17, 2016
Estrogen receptor alpha dinucleotide repeat and cytochrome P450c17alpha gene polymorphisms are associated with
Yao-Yuan Hsieh1, Chi-Chen Chang, Fuu-Jen Tsai
1Department of Obstetrics and Gynecology, China Medical University Hospital, Taichung, Taiwan.
Objective:
To investigate the association of endometriosis with estrogen receptor alpha (ER alpha) and cytochrome P450c17alpha (CYP17) gene polymorphisms in light of the fact that estrogen plays a role in the pathogenesis of endometriosis and the CYP17 enzyme is involved with estrogen biosynthesis.
Design:
Prospective study.
Setting:
Genetics and gynecology units.
Patient(S):
All patients were divided into two groups: group 1, women with endometriosis (n = 119); group 2, normal controls (n = 108).
Intervention(S):
A dinucleotide (thymine-adenine [TA]) repeat polymorphism lying upstream of the ER alpha gene and A1/A2 polymorphism of the CYP17 gene were amplified by polymerase chain reaction, enzyme restriction, and electrophoresis.
Main Outcome Measure(S):
The ER genotypes were classified into A through T (TA repeats, 10-29). The CYP17 genotypes included indigestible (A1 homozygote), heterozygote, and digestible (A2 homozygote). We compared these polymorphism distributions in both groups.
Result(S):
The percentage of genotypes D-G (TA, 13-16) in both groups were 10.5%, 29.4%, 13.0%, and 11.3% in group 1 and 7.9%, 16.7%, 19.9%, and 17.6% in group 2. The genotype E (14 TA repeats) is associated with a higher risk of endometriosis. Proportions of A1 homozygote/heterozygote/A2 homozygote for CYP17 were 26.1%/46.2%/27.7% for group 1 and 14.8%/44.5%/40.7% for group 2, respectively. The A1 homozygote and allele were associated with a higher susceptibility of endometriosis.
Conclusion(S):
ER alpha* 14 TA repeats and the CYP17* A1 allele are associated with an increased risk of endometriosis. Both polymorphisms are useful markers for predicting endometriosis susceptibility.
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