RESUMO
OBJECTIVE: To analyze whether telomere length, X-chromosome inactivation (XCI), and androgen receptor (AR) GAG polymorphism are related to idiopathic premature ovarian insufficiency (POI). DESIGN: Case-control study. SETTING: University hospital. PATIENT(S): A total of 121 women, including 46 nonsyndromic POI and 75 controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Age, weight, height, body mass index (BMI), systolic and diastolic arterial pressure, E2, androstenedione, T, and C-reactive protein were assessed. Telomere length was estimated by quantitative real-time polymerase chain reaction, XCI was measured using the Human Androgen Receptor and X-linked retinitis pigmentosa 2 (RP2) methylation assays. AR and FMR1 polymorphism was assessed by quantitative fluorescent polymerase chain reaction and sequencing. RESULT(S): Premature ovarian insufficiency women had a higher mean age, weighed less, and exhibited lower C-reactive protein, E2, and androstenedione levels. The AR polymorphism did not differ between the groups. Four patients had premutation (55-200 CGG repeats), and none displayed a full mutation in the FMR1 gene. However, patients with POI showed shorter telomere length and higher frequency of skewed XCI. Extreme skewing (≥90%) was observed in 15% of women with POI, and shorter telomeres correlated with XCI skewing in both groups. CONCLUSION(S): Skewed XCI and shortened telomere length were associated with idiopathic POI, despite no alterations in the AR and FMR1 genes. Additionally, there is a tendency for women with short telomeres to exhibit skewed XCI.
