Publications (151) View all
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Article: Genetic polymorphisms of the glucocorticoid receptor may affect the phenotype of women with anovulatory polycystic ovary syndrome.
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ABSTRACT: Polycystic ovary syndrome (PCOS) is characterized by ovarian dysfunction. The association with obesity and insulin resistance is well established. Steroid hormones play a central role in the regulation of both ovarian function and body composition. This study aims to assess the influence of known functional polymorphisms in genes that are responsible for the production, metabolism and signal transduction of steroid hormones on the susceptibility to and phenotype of PCOS. We included 518 Caucasian women with anovulatory PCOS (2003 Rotterdam criteria) and 2996 population-based controls. Functional polymorphic variants were selected in genes that affect the production of estradiol and cortisol [aromatase (CYP19), 11-beta-hydroxysteroid dehydrogenase type I (HSD11B1) and hexose-6-phosphate dehydogenase (H6PD)] and in genes for signal transduction proteins [estrogen receptor (ESR1 and ESR2) and glucocorticoid receptor (GCR)]. Genotype-frequencies were similar in PCOS cases and population-based controls. We observed possible associations between GCR genotype and LH levels that suggest an inhibitory influence of GCR, i.e., lower LH levels in association with GCR alleles that are known to increase receptor sensitivity (rs6195 and rs41423247) and higher LH levels in GCR variants that may inhibit receptor sensitivity (rs6190 and rs6198). The present study did not identify risk alleles for PCOS, although the study was limited by an absence of endocrine data for the population-based controls. However, GCR variants may influence gonadotrophin levels in women with anovulatory PCOS. We hypothesize that glucocorticoids can affect the function of the hypothalomo-pituitary-gonadal axis in humans.Human Reproduction 07/2011; 26(10):2902-11. · 4.47 Impact Factor -
Article: Anti-Mullerian hormone and ovarian dysfunction
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ABSTRACT: Anti-Mullerian hormone (AMH) has important roles in postnatal ovarian function. Produced by ovarian granulosa cells, AMH is involved in initial follicle development. In fact, serum AMH level correlates with ovarian follicle number. In patients with polycystic ovary syndrome (PCOS), AMH levels are elevated, which indicates its potential relevance in PCOS diagnosis and management. AMH represents a useful clinical marker for the assessment of ovarian reserve in cases of subfertility caused by advanced age in women. A potential role for AMH in dominant follicle selection has also been suggested. Future challenges comprise the availability of a well-standardized assay and the development of AMH agonists and antagonists as possible tools to manipulate ovarian function for contraception or ovarian longevity.Trends Endocrinol Metab. 01/2008; 19(9):340-7. -
Article: Anti-Mullerian hormone: a new marker for ovarian function
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ABSTRACT: Anti-Mullerian hormone (AMH) is a member of the transforming growth factor beta family of growth and differentiation factors. In the ovary, AMH has an inhibitory effect on primordial follicle recruitment as well as on the responsiveness of growing follicles to follicle-stimulating hormone (FSH). The ovary-specific expression pattern in granulosa cells of growing nonselected follicles makes AMH an ideal marker for the size of the ovarian follicle pool. This review summarizes recent findings concerning AMH and its role as a marker for the quantitative aspect of ovarian reserve as well as ovarian dysfunction.Reproduction. 01/2006; 131(1):1-9. -
Article: Novel insertion frameshift mutation of the LH receptor gene: problematic clinical distinction of Leydig cell hypoplasia from enzyme defects primarily affecting testosterone biosynthesis.
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ABSTRACT: Leydig cell hypoplasia (LCH) is a rare autosomal recessive condition that interferes with normal development of male external genitalia in 46,XY individuals and is caused by inactivating mutations of the LH receptor gene. The clinical and biochemical diagnostic parameters of LCH are not always specific and may therefore show significant overlap with other causes of insufficient testicular steroid biosynthesis. We have studied a 46,XY newborn with completely female external genitalia and palpable testes. Due to an increased basal serum ratio of androstenedione/testosterone, 17 beta-hydroxysteroid dehydrogenase type 3 (17 beta-HSD 3) deficiency was initially suspected. DNA analysis of the corresponding HSD17B3 gene, however, showed no abnormalities in the entire coding region. In contrast, direct sequencing of the LH receptor gene revealed a novel homozygous single nucleotide insertion in exon 11 (codon A589fs) producing a frame shift in the open reading frame predicting for premature termination of translation 17 amino acids downstream. From the genetic perspective, this mutation represents the first frame shift mutation in the LH receptor gene ever reported to date. From the clinical standpoint, LCH should always be considered in the differential diagnosis as steroid profiles may not be informative. Therefore, molecular genetic analysis should be warranted for androgen biosynthesis defects in all cases.European Journal of Endocrinology 03/2005; 152(2):255-9. · 3.42 Impact Factor -
Article: Anti-Müllerian hormone attenuates the effects of FSH on follicle development in the mouse ovary.
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ABSTRACT: Although ovarian follicle growth is under the influence of many growth factors and hormones of which FSH remains one of the most prominent regulators. Therefore, factors affecting the sensitivity of ovarian follicles to FSH are also important for follicle growth. The aim of the present study was to investigate whether anti-Müllerian hormone (AMH) has an inhibitory effect on follicle growth by decreasing the sensitivity of ovarian follicles to FSH. Furthermore, the combined action of AMH and FSH on ovarian follicle development was examined. Three different experiments were performed. Using an in vitro follicle culture system it was shown that FSH-stimulated preantral follicle growth is attenuated in the presence of AMH. This observation was confirmed by an in vivo experiment showing that in immature AMH-deficient females, more follicles start to grow under the influence of exogenous FSH than in their wild-type littermates. In a third experiment, examination of the follicle population of 4-month-old wild-type, FSH beta-, AMH-, and AMH-/FSH beta-deficient females revealed that loss of FSH expression has no impact on the number of primordial and preantral follicles, but the loss of inhibitory action of AMH on the recruitment of primordial follicles in AMH-deficient mice is increased in the absence of FSH. In conclusion, these studies show that AMH inhibits FSH-stimulated follicle growth in the mouse, suggesting that AMH is one of the factors determining the sensitivity of ovarian follicles for FSH and that AMH is a dominant regulator of early follicle growth.Endocrinology 12/2001; 142(11):4891-9. · 4.46 Impact Factor
