Functional genetic polymorphisms and female reproductive disorders: part II--endometriosis

BACKGROUND

Endometriosis has a strong genetic component, and numerous genetic studies have been reported.

METHODS

We have systematically reviewed these studies and included 114 in our final selection.

RESULTS

We found no consistent evidence linking endometriosis with specific polymorphisms in genes encoding inflammatory mediators, proteins involved in sex steroid metabolism, vascular function and tissue remodelling. Although a number of polymorphisms have been associated with endometriosis in selected populations, the associations have not been independently confirmed, either because only single studies were carried out on these markers/genes or because other studies reported no association. The most solid evidence linking specific polymorphisms to endometriosis came from studies investigating glutathione-S-transferase, a phase II detoxification enzyme. Carriage of the GSTT1 null deletion variant showed consistent association with endometriosis with a 29% increased risk; however, it cannot be excluded that this result was due to publication bias, and this association should be independently confirmed in large-scale, well-designed case–control studies.

CONCLUSIONS

The evidence of an association between genetic polymorphisms and endometriosis is weak. Carriage of the GSTT1 null deletion may moderately increase the risk of this disease. We suggest that the methodology of association studies should be improved in order to identify and validate associations in endometriosis.

Functional genetic polymorphisms and female reproductive disorders: Part I: Polycystic ovary syndrome and ovarian response

BACKGROUND

The identification of polymorphisms associated with a disease can help to elucidate its pathogenesis, and this knowledge can be used to improve prognosis for women with a particular disorder, such as polycystic ovary syndrome (PCOS). Since an altered response to ovarian stimulation is also a characteristic of the disease, further knowledge about its aetiology could help in defining the parameters that determine the response of an individual to ovarian stimulation.

METHODS

PubMed and EMBASE databases were systematically searched for gene association studies published until the end of August 2007, using search criteria relevant to PCOS and ovarian response to stimulation. Data from additional papers identified through hand searches were also included; 139 publications were reviewed.

RESULTS

Several genes involved in ovarian function and metabolism are associated with increased susceptibility to PCOS, but none is strong enough to correlate alone with susceptibility to the disease, or response to therapy. A single-nucleotide polymorphism in exon 10 of the FSH receptor (FSHR) gene, FSHR p.N680S, was consistently identified as having a significant association with ovarian response to FSH.

CONCLUSIONS

No consistent association between gene polymorphism and PCOS could be identified. The FSHR gene may play a significant role in the success of ovarian stimulation, and can be used as a marker to predict differences in FSHR function and ovarian response to FSH. Genotyping the FSHR p.N680S polymorphism may provide a means of identifying a population of poor responders before in vitro fertilization procedures are initiated.

Estrogen-metabolizing gene polymorphisms and age at natural menopause in Caucasian women

BACKGROUND

Lifestyle parameters, personal history and genetic factors are thought to affect the timing of natural menopause in humans. Based on their biological function, estrogen-metabolizing gene polymorphisms have been regarded as candidate genes for early menopause.

METHODS

In the present cross-sectional, multi-centre study, we analysed nine single nucleotide polymorphisms of six estrogen-metabolizing genes [three estrogen-synthesizing genes, i.e. 17-beta-hydroxysteroid dehydrogenase type 1 (17-beta HSD), cytochrome P-450 (CYP) 17 and CYP19; and three estrogen-inactivating genes, i.e. catechol-O-methyltransferase (COMT), CYP1A1 and CYP1B1] by sequencing-on-chip-technology in 1360 Caucasian women with natural menopause. Women's lifestyle parameters, reproductive and personal histories were ascertained.

RESULTS

Carriage of at least one mutant allele of the CYP1B1-4 Asn453Ser A--> G polymorphism (P = 0.004) and the number of full-term pregnancies (P < 0.001) were found to be independently associated with age at natural menopause. Women with at least one polymorphic allele of CYP1B1-4 experienced natural menopause earlier than non-carriers of the polymorphism [mean (SD) 48.6 (5.0) versus 49.4 (4.3) years]. Women with no, one, two and three or more full-term pregnancies experienced natural menopause at 48.5 (5.0), 48.8 (4.8), 49.5 (4.2) and 49.6 (4.6) years, respectively.

CONCLUSION

We present the most comprehensive data on estrogen-metabolizing gene polymorphisms and timing of natural menopause to date. The number of full-term pregnancies and the CYP1B1-4 polymorphism are significant predictors of timing of natural menopause in Caucasian women.

The size of a microsatellite polymorphism of the haem oxygenase 1 gene is associated with idiopathic recurrent miscarriage

Endothelial damage, impaired microvascularization and immune maladaptation have been described as aetiological factors in recurrent miscarriages. We investigated the relationship between idiopathic recurrent miscarriage (IRM) and a (GT)(n) repeat microsatellite polymorphism of the gene encoding haem oxygenase 1 (HO-1), known to modulate immune functions such as T-helper (TH) cell function and to be associated with cardiovascular disease. We investigated 162 women with IRM and 129 healthy, post-menopausal controls. The length of the HO-1 (GT)(n) microsatellite was assessed by PCR and direct sequencing in all women. Results were correlated with clinical data. The distribution of genotypes was in Hardy-Weinberg equilibrium. The HO-1 (GT)(n) microsatellite repeat numbers ranged from 13 to 37, with (GT)(23) and (GT)(30) being the most common alleles in both groups. We compared alleles consisting of < or =27 GT repeats, termed class S (short) alleles and alleles consisting of >28 GT repeats, termed class L (long) alleles. Seventy per cent of women with IRM had an S allele either in heterozygous (L/S) or homozygous (S/S) form, compared to 56% of controls (P = 0.02; OR 0.54; 95% CI 0.32-0.90). With respect to S allele frequencies, we found no significant difference among women with IRM and controls [P = 0.3; odds ratio (OR) 1.23, 95% confidence interval (CI) 0.86-1.76]. Comparing women with primary and secondary IRM, no difference with respect to the length of the HO-1 (GT)(n) microsatellite was ascertained. In summary, this is the first report on a HO-1 (GT)(n) microsatellite polymorphism among women with IRM, demonstrating that the investigated polymorphism is associated with IRM in a relatively large Caucasian population.

A polymorphism of the interleukin-6 gene promoter and idiopathic recurrent miscarriage

BACKGROUND

Cytokines have been described to play a major role in the pathogenesis of idiopathic recurrent miscarriage (IRM). We investigated the association between IRM and a polymorphism of the interleukin-6 (IL-6) gene and IL-6 serum levels.

METHODS

In a prospective case-control study, we studied 161 women with IRM and 124 healthy controls. Peripheral venous puncture, DNA extraction and PCR were employed to genotype women for the presence of a polymorphism at position -174 in the promoter region of IL-6. Serum IL-6 levels were assessed by a commercially available ELISA.

RESULTS

Allele frequencies among women with IRM and controls were 63.4 and 58.1% respectively for allele G (wild type), and 36.6 and 41.9% respectively for allele C (mutant). No association between allele C and the occurrence of IRM was found (odds ratio 0.8; 95% confidence interval = 0.57-1.12; P = NS). IL-6 serum levels were not significantly different between genotypes and between the study and control groups.

CONCLUSIONS

This is the first report on an IL-6 polymorphism in IRM. Although known to alter IL-6 expression, the IL-6 polymorphism investigated was not associated with IRM and alterations in IL-6 serum levels in a Middle-European Caucasian population.

An endothelial nitric oxide synthase gene polymorphism is associated with preeclampsia

OBJECTIVE

We sought to test the hypothesis that a polymorphism of the endothelial nitric oxide synthase gene (NOS3) is associated with preeclampsia.

METHODS

We collected and performed polymerase chain reaction (PCR) on genomic DNA from pregnant patients with and without preeclampsia. Patient history and clinical course were evaluated.

MAIN OUTCOME MEASURE(S)

Frequency of the intron 4 polymorphism of NOS3 (designated allele A) among patients with preeclampsia compared with controls. Clinical features of patients with preeclampsia and the A allele compared with those patients with preeclampsia who did not have the A allele.

RESULTS

The frequency of the A allele was 0.10 among controls versus 0.39 among patients with preeclampsia (p < 0.01). The odds ratio of developing preeclampsia when at least one A allele was present was 6.5 [95% confidence interval (CI): 2.1-19.7]. After adjusting for ethnic variation, the odds ratio increased to 7.2 (95% CI: 2.0-25.5). Among patients with preeclampsia, systolic blood pressure at the time of admission was higher for patients with at least one A allele compared with patients homozygous for the B allele (168 versus 156 mm Hg; p = 0.03), independent of gestational age (p = 0.01).

CONCLUSION

These data provide evidence for an association between NOS3 and preeclampsia. In defined ethnic groups, this NOS3 may offer predictive information regarding the subsequent development of preeclampsia and its clinical course.

Genetic modelling of the estrogen metabolism as a risk factor of hormone-dependent disorders

Estradiol is a pleiotropic hormone, involved in the etiology of a wide variety of diseases. Over the last decade individual genetic variability of the estradiol metabolism has been described as a significant contributor to disease susceptibility with variations depending on ethnic background. Among others, genetic variations of genes encoding cytochrome P450 (CYP) enzymes play an important role in this regard. Mutant alleles of the CYP 1A1 gene are major modulators of lung cancer risk among smokers, mediate gender differences in lung cancer susceptibility, and have been associated with an elevated risk for developing breast, prostate, colorectal, and oral squamous cell cancer. Variants of the CYP 1B1 gene modulate the risk for developing prostate, ovarian, lung, and breast cancer. Also, mutations in the CYP 1B1 gene are the major genetic determinant of congenital glaucoma. Mutant CYP 17 alleles are associated with serum and plasma levels of steroid hormones, use of hormone replacement therapy, and the development of endometrial, prostate, and breast cancer. Available data indicate that the protective effect against breast cancer of a later age at menarche is limited to wild-type CYP 17 allele carriers. Among women with the polycystic ovary syndrome, carriage of mutant CYP 17 alleles is sufficient to aggravate the clinical presentation of the disease. Molecular variants of the CYP 19 gene are associated with an increased risk for developing breast cancer, advanced breast cancer stages, and tumor aromatase production. Carriage of a mutant catechol-O-methyltransferase allele is associated with breast cancer, neurologic disorders such as Parkinson's disease, and modulates behavior among patients with schizophrenia, alcoholics and the general population. In summary, the available evidence points to genes that encode estrogen-metabolizing enzymes as strong hereditary determinants of the susceptibility to benign as well as malignant conditions.

Genetic modeling of estrogen metabolism as a risk factor of hormone-dependent disorders

Estradiol is a pleiotropic hormone, involved in the etiology of a wide variety of diseases. Over the last decade individual genetic variability of the estradiol metabolism has been described as a significant contributor to disease susceptibility with variations depending on ethnic background. Among others, genetic variations of genes encoding cytochrome P450 (CYP) enzymes play an important role in this regard. Mutant alleles of the CYP 1A1 gene are major modulators of lung cancer risk among smokers, mediate gender differences in lung cancer susceptibility, and have been associated with an elevated risk for breast, prostate, colorectal, and oral squamous cell cancer. Variants of the CYP 1B1 gene modulate the risk for prostate, ovarian, lung, and breast cancer. Also, mutations in the CYP 1B1 gene are the major genetic determinant of congenital glaucoma. Mutant CYP 17 alleles are associated with serum and plasma levels of steroid hormones, use of hormone replacement therapy, and endometrial, prostate, and breast cancer. Available data indicate that the protective effect of a later age at menarche is limited to mutant CYP 17 allele carriers. Among women with the Polycystic Ovary (PCO) syndrome, mutant CYP 17 alleles are sufficient to aggravate the clinical presentation of the disease. Molecular variants of the CYP 19 gene are associated with an increased risk for breast cancer, advanced disease stage, and tumor aromatase production. Carriage of a mutant catechol-O-methyltransferase (COMT) allele is associated with breast cancer, neurologic disorders such as Parkinson's disease, and modulates behavior among patients with schizophrenia, alcoholics and the general population. In summary, the available evidence points to estrogen metabolising genes as strong hereditary determinants of the susceptibility to benign and malignant conditions.

Tryptophan hydroxylase gene polymorphism (A218C) and idiopathic recurrent miscarriage

OBJECTIVE

To investigate the frequency of a polymorphism in intron 7 of the tryptophan hydroxylase gene among women with idiopathic recurrent miscarriage and healthy controls.

METHODS

In a case control study, we studied 125 women with a history of three or more consecutive pregnancy losses before 20 weeks' gestation and 137 healthy controls with at least two live births and no history of pregnancy loss. Peripheral venous puncture, DNA extraction, and polymerase chain reaction followed by restriction fragment length polymorphism analysis were used to genotype women for the presence of the A218C polymorphism in intron 7 of the tryptophan hydroxylase gene.

RESULTS

Allele frequencies among women with idiopathic recurrent miscarriage and controls were 32.4% and 38.7%, respectively, for allele A (wild type) and 67.6% and 61.3%, respectively, for allele C (mutant). No association between the presence of allele C and idiopathic recurrent miscarriage was found (P = .3; odds ratio 1.31; 95% confidence interval 0.93, 1.87). Genotype frequencies also were not significantly different between the study group (C/C: 44.8%; A/C: 45.6%; A/A: 9.6%) and the control group (C/C: 37.2%; A/C: 48.2%; A/A: 14.6%; P = .2). Between women with primary and women with secondary idiopathic recurrent miscarriage, no statistically significant differences with respect to allele frequencies were observed (63% vs 62% for allele C and 31% vs 38% for allele A; P = .3).

CONCLUSION

The A218C polymorphism in intron 7 of the tryptophan hydroxylase gene is not associated with idiopathic recurrent miscarriage.

The PROGINS progesterone receptor gene polymorphism and idiopathic recurrent miscarriage

OBJECTIVE

Progesterone inhibits lymphocyte cytotoxicity, natural killer cell degranulation, and release of proinflammatory cytokines and has been shown to protect against spontaneous miscarriage. We investigated the association between idiopathic recurrent miscarriage (IRM) and the PROGINS 306 base pair insertion polymorphism in intron G of the progesterone receptor gene, which is known to segregate with progesterone-dependent neoplasms.

METHODS

In a case-control study we investigated 125 women with a history of three or more consecutive pregnancy losses before 20 weeks' gestation and 79 healthy controls with at least two live births and no history of pregnancy loss. Peripheral venous puncture, DNA extraction, and polymerase chain reaction were used to genotype women for the presence of the PROGINS polymorphism.

RESULTS

Allele frequencies among women with IRM and controls were 85.2% and 89.2%, respectively, for allele T1 (wild type) and 14.8% and 10.8%, respectively, for allele T2 (mutant). No association between allele T2 and the occurrence of IRM was found (P =.3; odds ratio [OR] 0.69; confidence interval [CI] 0.34, 1.40). Genotype frequencies were not significantly different between the study group (T1/T1 73.6%, T1/T2 23.2%, T2/T2 3.2%) and the control group (T1/T1 79.7%, T1/T2 19%, T2/T2 1.3%) (P =.4). Between women with primary and secondary IRM, there were no statistically significant differences with respect to allele frequencies (82% versus 87%, P =.4 for allele T1 and 12% versus 13%, P =.6 for allele T2).

CONCLUSIONS

We found that the PROGINS polymorphism in the progesterone receptor gene was not associated with IRM in white women.

A polymorphism of the interleukin-1beta gene and idiopathic recurrent miscarriage

OBJECTIVE

Proinflammatory cytokines have been described to be involved in the pathogenesis of idiopathic recurrent miscarriage (IRM). We investigated the association between IRM and a polymorphism in exon 5 of the interleukin-1beta gene (IL1B) and interleukin-1beta (IL-1beta) serum levels.

DESIGN

Case control study.

SETTING

Academic research institution.

SUBJECTS

One hundred thirty-one women with a history of three or more consecutive pregnancy losses before 20 weeks' gestation and 68 healthy controls with at least two live births and no history of pregnancy loss.

INTERVENTIONS

Peripheral venous puncture.

MAIN OUTCOME MEASURES

An IL1B exon 5 (position +3953) gene polymorphism was analyzed by PCR amplification followed by restriction fragment length polymorphism analysis. IL-1beta serum levels were analyzed by a commercially available ELISA.

RESULTS

Allele frequencies in women with IRM and controls were 77.9% and 80.8%, respectively, for the E1 allele (wild type), and 22.1% and 19.2%, respectively, for the E2 allele (mutant). No association between the E2 allele and the occurrence of IRM was found (P=.57, odds ratio =.83). Genotype frequencies and IL-1beta serum levels were not significantly different between the study group and the control group.

CONCLUSIONS

This is the first report on an IL1B polymorphism in IRM. Although known to alter IL-1beta expression, the investigated IL1B polymorphism is not associated with IRM and increased serum levels in a large Caucasian population.

Placental expression and serum levels of cytokeratin-18 are increased in women with preeclampsia

OBJECTIVE

To evaluate placental expression and serum cytokeratin-18 in women with preeclampsia.

METHODS

Serum cytokeratin-18 was evaluated in 44 women with preeclampsia and 44 healthy pregnant women using an immunoradiometric assay. Placental expression of cytokeratin-18 was investigated in specimens from 23 women with preeclampsia and 20 healthy pregnant women by immunohistochemistry.

RESULTS

Median serum cytokeratin-18 in women with preeclampsia and healthy pregnant women was 106.7 and 76.0 U/L, respectively (P =.02). Among women with preeclampsia, serum cytokeratin-18 was significantly associated with severity of disease (P =.001) and showed a sensitivity (standard error) and specificity (standard error) of 85% (7%) and 65% (12%), respectively. In placental specimens, the cytoplasm of the syncytiotrophoblast stained positive for cytokeratin-18 with strong and widespread staining in 83% and 45% of placental specimens of women with preeclampsia and healthy pregnant women, respectively (P =.01).

CONCLUSION

Elevated serum cytokeratin-18 values are associated with disease severity in women with preeclampsia. Our data provide additional evidence that the placenta might be the source of the elevated serum cytokeratin-18 values in women with preeclampsia.

Polymorphisms within the interleukin-1 beta gene cluster and preeclampsia

OBJECTIVE

To identify associations between polymorphisms within the interleukin-1 beta gene cluster, all of which increase protein expression, and preeclampsia.

METHODS

We genotyped a Hispanic population (69 women with preeclampsia and 47 controls) for two polymorphisms of the interleukin-1 beta gene (promoter region and exon 5) and one polymorphism of the interleukin-1 receptor antagonist gene in intron 2. Clinical data were collected from medical records. Values are given as means or medians. Statistical power to identify a difference in occurrence of interleukin-1 beta promoter, interleukin-1 beta exon 5, and interleukin-1 receptor antagonist gene polymorphisms in women with preeclampsia compared with controls was 21%, 15.9%, and 30.9%, respectively.

RESULTS

We found no association between any single polymorphism and occurrence of preeclampsia. Among women with preeclampsia, those with polymorphism of interleukin-1 receptor antagonist gene had higher mean systolic blood pressure (BP) at admission (178 +/- 33.4 versus 159 +/- 19.5 mmHg, P =.039). When all three polymorphisms combined were evaluated, women with preeclampsia and at least three mutant alleles (n = 8) had higher mean systolic BP at admission (182 +/- 30 versus 160 +/- 20.5 mmHg, P =.009) and increased alanine aminotransferase (67 [10--1024] versus 20 [3--407] IU/L, P =.04) and aspartate aminotransferase (119 [25--2239] versus 24 [4--489] IU/L, P =.002). At admission, BP in controls was independent of any polymorphism identified.

CONCLUSION

Although the power of this study was limited, our data do not support a role for polymorphisms of the interleukin-1 beta and interleukin-1 receptor antagonist genes in the pathogenesis of preeclampsia among Hispanic women. Our findings do suggest that polymorphisms within the gene cluster might influence severity of preeclampsia.

Endothelial-derived nitric oxide and angiotensinogen: blood pressure and metabolism during mouse pregnancy

The regulation of blood pressure during pregnancy involves several biological pathways. Candidate genes implicated in hypertensive diseases during pregnancy include those of the renin-angiotensin system and nitric oxide synthase (NOS). We evaluated blood pressure and metabolic characteristics during pregnancy in mutant mice. These included mice with a null mutation in the endothelial NOS (eNOS) gene (Nos3(-/-)), four copies of the angiotensinogen gene (Agt(2/2)), and mutations in both genes [four copies of Agt and heterozygous deficient for eNOS (Agt(2/2)Nos3(+/-)), four copies of Agt and homozygous deficient for eNOS (Agt(2/2)Nos3(-/-))]. Blood pressure measurements of nulliparous females from mutant strains were compared with two common laboratory strains C57Bl6/J and SV129 throughout their first pregnancy. Serum and urine analysis for the evaluation of renal and liver physiology were measured in the prepregnant state and during the third trimester of pregnancy. Throughout pregnancy blood pressures in all mutant strains were higher compared with controls. Agt(2/2)Nos3(-/-) showed the highest blood pressures and C57Bl6/J the lowest. Control mice, but not mutant mice, showed a second trimester decline in blood pressure. No immediate differences were noted regarding behavioral characteristics, renal or liver function parameters. Mice deficient for eNOS, mice with overexpression of Agt, and mice with mutations in both genes demonstrated higher blood pressure throughout pregnancy. There was no evidence of renal dysfunction, liver dysfunction, or hemolysis among any of the strains studied. We conclude that Nos3 and Agt are important genes in the regulation of blood pressure during pregnancy.

The clinical value of serum concentrations of cancer antigen 125 in patients with primary fallopian tube carcinoma: a multicenter study

BACKGROUND

Primary fallopian tube carcinoma (PFTC) is a rare disease, and data on the serum concentration of tumor marker cancer antigen 125 (CA 125) in patients with this disease are sparse. The authors assessed the clinical value of the serum concentration of CA 125 as a prognostic and monitoring marker in patients with surgically treated PFTC.

METHODS

In a multicenter study, the concentration of CA 125 was measured in 406 serum samples from 53 patients with PFTC. The results were correlated with clinical data.

RESULTS

The pretreatment median serum CA 125 level was 183 U/mL (range, 6.5-5440.0 U/mL) in patients with PFTC. In a univariate Cox regression model, tumor stage and serum CA 125 level were associated significantly with shortened disease free survival (P = 0.006 and P < 0.001, respectively) and with overall survival (P = 0.03 and P = 0. 001, respectively). Lymph node involvement, tumor grade, and patient age were not associated with the length of survival. A multivariate Cox regression model showed that pretreatment the serum CA 125 level was a prognostic factor of disease free and overall survival, independent of tumor stage (P = 0.005 and P = 0.01, respectively). The pretreatment serum CA 125 level was correlated with tumor stage (P < 0.001) but not with lymph node involvement (P = 0.8), histologic grade (P = 0.3), or patient age (P = 0.2). The serum CA 125 level during chemotherapy was correlated significantly with Gynecologic Oncology Group response criteria to chemotherapy (P = 0. 001). During the follow-up of patients, serum CA 125 levels reached sensitivity, specificity, positive predictive value, and negative predictive value of 92%, 90%, 67%, and 98%, respectively, for differentiating between no evidence of disease and the presence of recurrent disease. In 90% of the patients, an increase of serum CA 125 level preceded the clinical or radiologic diagnosis of recurrent disease with a median lead time of 3 months (range, 0.5-7.0 months).

CONCLUSIONS

This is the largest study to date with respect to serum CA 125 levels in patients with PFTC. The current data indicate that the pretreatment serum CA 125 level is an additional independent prognostic factor of disease free and overall survival in patients with PFTC. The serum CA 125 level adequately defines the response to chemotherapy and displays good sensitivity and specificity characteristics during the follow-up of patients with PFTC.

Placental expression and serum concentrations of cytokeratin 19 in preeclampsia

OBJECTIVE

To evaluate cytokeratin 19 as a serum marker of preeclampsia.

METHODS

Serum cytokeratin 19 levels were measured in 46 women with preeclampsia and 46 controls matched for gestational age and parity, using an immunoradiometric assay. Cytokeratin 19 was evaluated immunohistochemically in placental specimens from 28 healthy pregnant women and 24 women with preeclampsia.

RESULTS

Cytokeratin 19 was identified in the syncytiotrophoblast in 13 (46. 4%) of 28 and 23 (95.8%) of 24 placental specimens from controls and women with preeclampsia, respectively (P =.03). Median serum levels of cytokeratin 19 in controls and women with preeclampsia were 1.7 (range 0.3-4.7) microg/mL and 2.7 (range 0.8-8.2) microg/mL, respectively (P <.001). Cytokeratin 19 significantly influenced the odds of presenting with preeclampsia (P <.001) and the odds of developing severe disease (P <.001). Serum cytokeratin 19 correlated inversely with fetal birth weight (Kendall tau-b correlation coefficient = -0.2, P =.007). Compared with healthy pregnant women, women with severe preeclampsia had significantly higher and more rapidly increasing cytokeratin 19 serum levels throughout the third trimester (P <.001).

CONCLUSION

Placental stimulation of cytokeratin 19, and release of it into maternal circulation, seem to be a feature of preeclampsia. Correlations with clinical characteristics suggest that cytokeratin 19 is a marker of disease severity.

Genetic control of fertility and embryonic waste in the mouse: A rolefor angiotensinogen

The purpose of this study was to evaluate the impact of angiotensinogen gene (Agt) deficiency on reproductive fitness in a rodent model. Mice with 0 (Agt(-/-)), 1 (Agt(-/+)), and 2 (Agt(+/+)) copies of Agt were bred according to the following schemes: 1) Agt(-/-) x Agt(-/-), 2) Agt(-/+) x Agt(-/+), 3) Agt(+/+) x Agt(+/+), and 4) Agt(+/+) female symbol x Agt(-/+) male symbol. There were 4 breeding pairs per scheme. Breedings were time mated. Mice and litters were weighed daily. Southern blotting was used for genotyping. We found that Agt(-/-) breeding pairs had fewer litters (2 [range 1-2] vs. 4 [range 3-5]; P = 0.01), fewer pups per litter (4 [range 1-7] vs. 6 [range 1-10]; P = 0.006), and longer interpregnancy intervals (43 days [range 31-44] vs. 35.5 days [range 22-58]; P = 0.04) compared to wild-type controls. The ratio of postcoital plugs to subsequent litters was 4.0 and 1.2 for Agt(-/-) and Agt(+/+) breedings, respectively (P = 0.03). Median maternal weights during all trimesters of pregnancy were significantly lower for Agt-deficient mice compared to wild-type controls. Among Agt(-/+) x Agt(-/+) breedings, the proportions of Agt(+/+) (n = 17), Agt(-/+) (n = 38), and Agt(-/-) (n = 4) offspring differed significantly from the expected 1:2:1 Mendelian inheritance pattern (P = 0.03). Neonatal survival among the offspring derived from the Agt(-/-) x Agt(-/-) breeding scheme was significantly reduced (P = 0. 001). We conclude that Agt deficiency is associated with an in utero lethal effect, decreased fertility, and impaired neonatal survival.