CAG repeat polymorphism in healthy women
Ralitsa Robeva, Desislava Dobreva, Georgi Kirilov, Analia Tomova, Aleksey Savov & Filip Kumanov
Androgen receptor (AR) containes a variable polyglutamine chain that is determined by the different number of CAG repeats in the AR gene on the X chromosome. The transactivational competence of AR is inversely related to the length of the polyglutamine chain, respectively to the CAG repeat number. Therefore, we investigated the role of the androgen receptor polymorphism in healthy hirsute and non hirsute women.
CAG repeat length polymorphism was analyzed in 52 women with regular menstrual cycle and normal ovarian function. Eleven of them were hirsute and in all of them hormonal disturbances were excluded. The short allele, the long allele and the mean biallelic number were determined in each person. The anthropometric values, modified Ferriman-Gallwey score, and the serum levels of testosterone, SHBG, free testosterone, LH, FSH, estradiol, insulin and lipid profile were also examined.
Mean numbers of CAG repeats in the long allele and the short allele as well as the mean biallelic number did not differ between the hirsute and non hirsute women. In the whole group the women with smaller mean biallelic number were a little younger (28.96±4.63 vs 31.46±4.29, P=0.049), with lower levels of the HDL-cholesterol (1.28±0.28 vs 1.58±0.32 mmol/l, P=0.024), higher levels of LDL-cholesterol (2.76±0.58 vs 2.33±0.36 mmol/l, P=0.037) and higher DHEAS concentrations (9.07±4.86 vs 6.38±3.41 μml/ml, P=0.033) in comparison to the others. The women with higher CAG number in the long allele had lower FG score (P=0.049) and better lipid profile with higher HDL-cholesterol (1.54±0.35 vs 1.24±0.18 mmol/l, P=0.031) and lower triglycerides (0.64±0.38 vs 0.98±0.49 mmol/l, P=0.048). Women with lower CAG number in the short allele did not differ in their hormonal indices in comparison to the others.
In conclusion CAG repeat polymorphism could modulate the degree of body hair growth and the lipid profile in healthy women.
Supported by: National Science Fund, MOMN, L-1504/2005.