Uterine leiomyomas in hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome can be identified through distinct clinical characteristics and typical morphology

INTRODUCTION

Hereditary leiomyomatosis and renal cell cancer (HLRCC) constitute a tumor susceptibility syndrome caused by germline mutations in the fumarate hydratase (FH) gene. The most common features are leiomyomas of the uterus and the skin. The syndrome includes a predisposition to early-onset, aggressive renal cell cancer. It is important to identify women with HLRCC among other uterine leiomyoma patients in order to direct them to genetic counseling and to identify other affected family members.

MATERIAL AND METHODS

We conducted a nationwide historical study to identify typical clinical characteristics, uterine leiomyoma morphology, and immunohistochemistry for diagnosing HLRCC. The study included 20 women with a known FH germline mutation and 77 women with sporadic uterine leiomyomas. The patient records of all women were reviewed to obtain clinical details regarding their leiomyomas. Uterine leiomyoma tissue specimens from 43 HLRCC-related leiomyomas and 42 sporadic leiomyomas were collected and prepared for histology analysis. A morphologic description was performed on hematoxylin & eosin-stained tissue slides, and immunohistochemical analysis was carried out for CD34, Bcl-2, and p53 stainings.

RESULTS

The women with HLRCC were diagnosed with uterine leiomyomas at a young age compared with the sporadic leiomyoma group (mean 33.8 years vs. 45.4 years, P < 0.0001), and their leiomyomas occurred as multiples compared with the sporadic leiomyoma group (more than four tumors 88.9% vs. 30.8%, P < 0.0001). Congruently, these women underwent surgical treatment at younger age compared with the sporadic leiomyoma group (mean 37.3 years vs. 48.3 years, P < 0.0001). HLRCC leiomyomas had denser microvasculature highlighted by CD34 immunostaining when compared with the sporadic leiomyoma group (112.6 mean count/high-power field, SD 20.8 vs. 37.4 mean count/high-power field, SD 21.0 P < 0.0001) and stronger anti-apoptotic protein Bcl-2 immunostaining when compared with the sporadic leiomyoma group (weak 4.7%, moderate 44.2%, strong 51.2% vs. 26.2%, 52.4%, 21.4%, respectively, P = 0.003). No differences were observed in p53 staining.

CONCLUSIONS

Women with HLRCC may be identified through the distinct clinical characteristics: symptomatic and numerous leioymyomas at young age, and morphologic features of FH-mutant leiomyomas, aided by Bcl-2 and CD34 immunohistochemistry. Further, distinguishing individuals with a germline FH mutation enables proper genetic counseling and regular renal monitoring.

Intrauterine growth restriction and placental gene expression in severe preeclampsia, comparing early-onset and late-onset forms

OBJECTIVE

To evaluate placental gene expression in severe early- or late-onset preeclampsia with intrauterine growth restriction compared to controls.

STUDY DESIGN

Chorionic villus sampling was conducted after cesarean section from the placentas of five women with early- or late-onset severe preeclampsia and five controls for each preeclampsia group. Microarray analysis was performed to identify gene expression differences between the groups.

RESULTS

Pathway analysis showed over-representation of gene ontology (GO) biological process terms related to inflammatory and immune response pathways, platelet development, vascular development, female pregnancy and reproduction in early-onset preeclampsia. Pathways related to immunity, complement and coagulation cascade were overrepresented in the hypergeometric test for the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Ten genes (ABI3BP, C7, HLA-G, IL2RB, KRBOX1, LRRC15, METTL7B, MPP5, RFLNB and SLC20A) had a ≥±1 fold expression difference in severe early-onset preeclampsia group compared to early controls. There were 362 genes that had a ≥±1 fold expression difference in severe early-onset preeclampsia group compared to late-onset preeclampsia group including ABI3BP, C7, HLA-G and IL2RB.

CONCLUSION

There are significant differences in placental gene expression between severe early- and late-onset preeclampsia when both are associated with intrauterine growth restriction. ABI3BP, C7, HLA-G and IL2RB might contribute to the development of early form of severe preeclampsia.

First-Trimester Maternal Serum Amino Acids and Acylcarnitines Are Significant Predictors of Gestational Diabetes

BACKGROUND

Current screening methods for gestational diabetes mellitus (GDM) are insufficient in detecting the risk of GDM in the first trimester of the pregnancy. Recent metabolomic studies have detected altered amino acid and acylcarnitine concentrations in type 2 diabetes (T2D). Because of the similarities between T2D and GDM, the determination of these metabolites may be useful in early screening for GDM.

AIM

To evaluate the association between GDM and first-trimester maternal serum concentrations of ten amino acids and 31 acylcarnitines.

METHODS

This retrospective case-control study included data from pregnant women screened at Oulu University Hospital between 1.1.2008 and 31.12.2011. A total of 31,146 women participated voluntarily in a first-trimester combined screening (for chromosomal abnormalities). The study population included 69 women who developed GDM during pregnancy and 295 women without diabetes before or after pregnancy. The serum concentrations of ten amino acids and 31 acylcarnitines were analyzed from frozen serum samples taken in the first-trimester screening. Multiple of median (MoM) values were compared between the two groups.

RESULTS

In the GDM group, serum levels of arginine were significantly higher (1.13 MoM vs. 0.97 MoM), and those of glycine (0.93 MoM vs. 1.03 MoM) and 3-hydroxy-isovalerylcarnitine (0.86 MoM vs. 1.03 MoM) significantly lower compared to the control group (all p < 0.01). In each case, arginine, glycine, and 3-hydroxy-isovaleryl-carnitine would have detected 46%, 32%, and 39% of GDM cases, with a false-positive rate of 20%. Combining these three metabolites with the first-trimester serum marker pregnancy-associated plasma protein A (PAPP-A) and prior risk (age, BMI, and smoking) achieved a detection rate of 72%.

CONCLUSION

There are significant differences in the serum levels of arginine, glycine, and 3-hydroxy-isovalerylcarnitine between controls and women who subsequently develop GDM. These differences were already existent in the first trimester of the pregnancy. The use of metabolites in combination with prior risk and first-trimester PAPP-A represents a reliable method to identify women at risk of GDM.

Uterine fibroids and cardiovascular risk

STUDY QUESTION

Are uterine fibroids associated with increased cardiovascular risk?

SUMMARY ANSWER

This study reports an association between increased serum lipids and metabolic syndrome with an increased risk of uterine fibroids.

WHAT IS KNOWN ALREADY

Recent studies suggest similarities in biological disease mechanisms and risk factors for fibroids and atherosclerosis: obesity, hypertension and abnormal serum lipids. These findings are awaiting confirmation that a population-based follow-up study could offer with extensive health examination data collection linked with a national hospital discharge register.

STUDY DESIGN, SIZE, DURATION

The Northern Finland Birth Cohort (NFBC1966) is a population-based long-term follow-up study including all children with estimated date of delivery in 1966 in the Northern Finland area. The data were collected from national registries, postal questionnaires and clinical health examinations. The study population for this study comprised all females included in the NFBC1966 that underwent an extensive clinical health examination at age 46 years (n = 3635).

PARTICIPANTS/MATERIALS, SETTING, METHODS

All females included in the NFBC1966 who were alive and traceable (n = 5118) were invited for the 46-year follow-up study; 3268 (63.9%) responded, returned the postal questionnaire and attended the clinical examination. Uterine fibroid cases were identified through the national hospital discharge register that has data on disease diagnoses based on WHO ICD-codes. Uterine fibroid codes, ICD-9: 218 and ICD-10: D25 were used for case identification. Self-reported fibroid cases were identified through the postal questionnaire.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 729 fibroid cases were identified, including 293 based on hospital discharge registries. With adjustment for BMI, parity, education and current use of exogenous hormones the risk of prevalent fibroids rose significantly for every 1 mmol/l increase in LDL (OR = 1.13, 95% CI: 1.02-1.26 for all cases) and triglycerides (OR = 1.27, 95% CI: 1.09-1.49 for all cases). Metabolic syndrome associated with hospital discharge-based fibroid diagnosis (OR = 1.48, 95% CI: 1.09-2.01). Additionally every 1 unit increase in waist-hip ratio associated with fibroids (OR = 1.32, 95% CI: 1.10-1.57).

LIMITATIONS, REASONS FOR CAUTION

The case ascertainment may present some limitations. There was likely an under-identification of cases and misclassification of some cases as controls; this would have diluted the effects of reported associations. The data analysed were cross-sectional and therefore cause and effect for the associations observed cannot be distinguished.

WIDER IMPLICATIONS OF THE FINDINGS

Increased serum lipids and metabolic syndrome are associated with increased risk of uterine fibroids. Along with central obesity these findings add to an increased risk for cardiovascular disease among women with fibroids. These observations may suggest that there are shared predisposing factors underlying both uterine fibroids and adverse metabolic and cardiac disease risk, or that metabolic factors have a role in biological mechanisms underlying fibroid development.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the Academy of Finland, University Hospital Oulu, University of Oulu, Finland, Northern Finland Health Care Foundation, Duodecim Foundation, ERDF European Regional Development Fund-Well-being and health: Research in the Northern Finland Birth Cohort 1966. The authors declare no conflict of interest.

Strong family history of uterine leiomyomatosis warrants fumarate hydratase mutation screening

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a tumor predisposition syndrome characterized by cutaneous and uterine leiomyomas and renal cell cancer. HLRCC is caused by heterozygous germline mutations in the fumarate hydratase (FH) gene. A Finnish family with nine closely related women with uterine leiomyomas was detected by an alert gynecologist. No cutaneous or renal cell tumors were reported in the family when it was referred to genetic analyses. Samples were available from seven patients, and a novel germline FH mutation was detected in five of them. Mutation carriers were symptomatic, had multiple tumors and were diagnosed at an early age. This study emphasizes the importance of considering FH mutation screening when gynecologists encounter families with multiple severe uterine leiomyoma cases. Due to possibility of phenocopies more than one patient should be tested. Early mutation detection allows regular screening of the mutation carriers and enables early detection of possible highly aggressive renal tumors. It may also affect family planning as multiple myomas at early age may significantly reduce fertility.

Do symptomatic endometriosis and uterine fibroids appear together?

OBJECTIVES:

Endometriosis and uterine fibroids are common gynecological disorders in fertile women. It has been suggested that these two disorders may be associated with each other. In this study, we tested whether this connection exists. In addition, we wanted to evaluate whether they both affect fertility independently of each other.

MATERIALS AND METHODS:

The prevalence of endometriosis and uterine fibroids was investigated in three groups of patients: Symptomatic patients requiring surgery either for endometriosis (n=182), or for uterine fibroids (n=240) and asymptomatic patients undergoing laparoscopic sterilization (n=183). The prevalences were examined in three age groups: 35–39 yrs, 40–44 yrs and ≥ 45 yrs. The significance of both diagnoses on fertility was assessed using logistic regression analysis.

RESULTS:

Uterine fibroids were detected in 25.8% (47/182) of patients with endometriosis. Endometriosis was detected in 19.6% (47/240) of patients with uterine fibroids. 5.5% (10/183) women undergoing sterilization had endometriosis and 19.3% (17/183) had uterine fibroids. Both uterine fibroids and endometriosis were, independently of each other, related to subfertility (OR, 95% CI: 3.8, 2.3–6.5; 6.8, 4.0–11.6, respectively).

CONCLUSIONS:

The results suggest that symptomatic endometriosis appears together with symptomatic uterine fibroids. Both diseases seem to decrease female fertility independently of each other.

Effect of a new marker, ADAM12, on Down risk figures in first trimester screening

OBJECTIVE

To investigate whether incorporating the measurement of ADAM12 in the risk calculation program LifeCycle, can improve Down screening in the first trimester.

METHODS

In a retrospective case control study, maternal serum ADAM12 concentrations were measured and compared in Down syndrome cases (n = 53) and in controls (n = 226) obtained from first trimester (9-12 weeks) screening samples in Oulu and Kuopio University Hospitals. Median concentration ( microg/l), observed and regressed (weight corrected) MoMs of ADAM12 were calculated.

RESULTS

There was a significant difference in ADAM12 levels between Downs and controls during the pregnancy weeks 9 + 0 to 10 + 6, but not thereafter. By adding ADAM12 to the marker set used in the risk calculation program, one screening false negative Down syndrome case occurred in the affected population, which did not alter false positive rate.

CONCLUSION

Adding ADAM12 as a parameter in Down screening did not cause radical changes in the risk value. The test might be useful at 9 and 10 weeks in which it might have the potential to improve the performance of the risk assessment especially for women receiving a result close to the high-risk cut-off. The real influence of ADAM12 remains to be elucidated in larger studies incorporating ADAM12 to the risk calculation program.

Screening for BRCA1 and BRCA2 mutations in Eastern Finnish breast/ovarian cancer families

Familial aggregation is thought to account for 5-10% of all breast cancer cases, and high penetrance breast and ovarian cancer susceptibility genes BRCA1 and BRCA2 explain < or =20% of these. Hundreds of mutations among breast/ovarian cancer families have been found in these two genes. The mutation spectrum and prevalence, however, varies widely among populations. Thirty-six breast/ovarian cancer families were identified from a population sample of breast and ovarian cancer cases among a relatively isolated population in Eastern Finland, and the frequency of BRCA1/BRCA2 germline mutations were screened using heteroduplex analysis, protein truncation test and sequencing. Five different mutations were detected in seven families (19.4%). Two mutations were found in BRCA1 and three in BRCA2. One of the mutations (BRCA2 4088insA) has not been detected elsewhere in Finland while the other four, 4216-2nt A-->G and 5370 C-->T in BRCA1 and 999del5 and 6503delTT in BRCA2, are recurrent Finnish founder mutations. These results add to the evidence of the geographical differences in distribution of Finnish BRCA1/BRCA2 mutations. This screen also provides further evidence for the presumption that the majority of Finnish BRCA1/BRCA2 founder mutations have been found and that the proportion of BRCA1/BRCA2 mutations in Finnish breast/ovarian cancer families is around 20%.

Fortified mineral water improves folate status and decreases plasma homocysteine concentration in pregnant women

OBJECTIVES

There is no mandatory folic acid fortification of food in Finland. We investigated the effects of mineral water fortified with folic acid, vitamins B6, B12, D and calcium on serum and erythrocyte folate concentrations, serum vitamin B12 and plasma homocysteine concentrations in pregnancy.

DESIGN

A randomized, controlled, double-blind, parallel-group intervention study.

METHODS

Seventy-four pregnant women were recruited from two health care units. The study began at the eleventh week with a two-week run-in period, followed by an eight-week intervention period. The diet was monitored by food records. During the intervention, subjects consumed 1000 mL/day fortified or normal mineral water. The pregnancies were monitored carefully.

RESULTS

The folate intake was 255 microg/day in the study group and 274 microg/day in the controls. Serum folate concentrations increased in the study group by 10.3 nmol/L and decreased in the controls by 2.7 nmol/L (P<0.05) during the study. The erythrocyte folate concentrations increased in the study group by 360.9 nmol/L and in the controls by 195.6 nmol/L (P=0.004) and serum homocysteine concentrations fell by 1.1 micromol/L and by 0.3 micromol/L, respectively (P<0.05).

CONCLUSIONS

Finnish pregnant women have low dietary folate intake. Fortified mineral water improved folate status and reduced plasma homocysteine concentrations in the pregnant subjects.

First Trimester Down’s Syndrome Screening Shows High Detection Rate for Trisomy 21, but Poor Performance in Structural Abnormalities – Regional Outcome Results

OBJECTIVE

To evaluate whether first trimester screening markers are altered in pregnancies affected both by other chromosomal defects than trisomy 21 and structural anomalies and whether it is possible to detect these pregnancies by combined ultrasound and biochemical screening test.

METHODS

Altogether 4,776 singleton pregnancies underwent first trimester screening. Of them, 3,101 women were screened using a combination of maternal serum free hCG, pregnancy-associated plasma protein A and nuchal translucency and 1,361 women with first trimester biochemistry without ultrasound. Nuchal translucency screening was performed between the 11th and 13+6th gestational weeks, and biochemistry 1-2 weeks earlier.

RESULTS

Using a fixed cut-off rate of 1:250 for Down's syndrome, the detection rate of trisomies 21, 18 and 13 were 92, 67 and 0%, respectively. All open defects, 85% of cardiac defects and other minor defects were not detected in first trimester screening. Majority of these structural abnormalities occurred in women under 35 years of age.

CONCLUSION

First trimester Down's syndrome screening is effective in trisomy screening, but its performance in structural abnormalities is low, when used as a part of routine clinical practice. We conclude that it is too early to drop second trimester screening ultrasound entirely from antenatal care programs if a high detection rate is to be achieved also in structural defects.

The influence of smoking on the pregnancy-associated plasma protein A, free beta human chorionic gonadotrophin and nuchal translucency

OBJECTIVE

To analyse the effects of smoking on first trimester parameters used in prenatal screening for Down's Syndrome.

DESIGN

A chart study.

SETTING

Primary care centres and maternity clinics of the participating universities' and central hospitals.

POPULATION

Three thousand and one hundred fifteen women screened by nuchal translucency measurement and 4436 women screened by maternal serum samples. Only normal singleton pregnancies were included.

METHODS

The mean multiples of median of pregnancy associated plasma protein A (PAPP-A), free beta human chorionic gonadotrophin (beta-hCG) and nuchal translucency were compared by independent samples t test after logarithmic transformation of the data between smokers and non-smokers.

MAIN OUTCOME MEASURES

PAPP-A and free beta-hCG concentrations and nuchal translucency measurements.

RESULTS

PAPP-A was significantly reduced and nuchal translucency increased if the mother smoked. The smokers were more frequently considered as being at high risk for Down's Syndrome.

CONCLUSIONS

Correcting PAPP-A median for smokers down by 20% might improve the accuracy of the risk evaluations given to individual women. If the association between increased nuchal translucency and smoking can be confirmed, it poses interesting questions as to the reasons for increased nuchal translucency among normal pregnancies.

Augmentation of auditory N1 in children with fragile X syndrome

We compared the N1 responses of the auditory event-related brain potentials (ERPs) in school-aged children with fragile X syndrome to age-matched controls in order to assess auditory processing. Event-related potentials to non-attended standard and deviant tone stimuli were recorded with EEG electrodes and here the standard tones were analysed. The amplitude of the N1 component to standard tones was significantly larger in children with fragile X syndrome than in control children. In addition, the global field power maximum of ERP corresponding to the N2 component was significantly (p<0.05) larger in fragile X children than in controls. The N2 scalp distribution in children with fragile X syndrome appeared more frontal than that in controls. Furthermore, the fragile X children exhibited no habituation of N1 and an absence of N2 sensitization for repeated tones. Increased responsiveness observed in the N1 evoked potential together with abnormal habituation of auditory responses in childhood may indicate increased sensory sensitivity for auditory stimuli in fragile X syndrome. The data, though very limited, suggest that stimulus processing in the auditory afferent pathways and/or in the corresponding cortical receiving areas is abnormal in children with fragile X syndrome.

Search for intracranial aneurysm susceptibility gene(s) using Finnish families

BACKGROUND

Cerebrovascular disease is the third leading cause of death in the United States, and about one-fourth of cerebrovascular deaths are attributed to ruptured intracranial aneurysms (IA). Epidemiological evidence suggests that IAs cluster in families, and are therefore probably genetic. Identification of individuals at risk for developing IAs by genetic tests will allow concentration of diagnostic imaging on high-risk individuals. We used model-free linkage analysis based on allele sharing with a two-stage design for a genome-wide scan to identify chromosomal regions that may harbor IA loci.

METHODS

We previously estimated sibling relative risk in the Finnish population at between 9 and 16, and proceeded with a genome-wide scan for loci predisposing to IA. In 85 Finnish families with two or more affected members, 48 affected sibling pairs (ASPs) were available for our genetic study. Power calculations indicated that 48 ASPs were adequate to identify chromosomal regions likely to harbor predisposing genes and that a liberal stage I lod score threshold of 0.8 provided a reasonable balance between detection of false positive regions and failure to detect real loci with moderate effect.

RESULTS

Seven chromosomal regions exceeded the stage I lod score threshold of 0.8 and five exceeded 1.0. The most significant region, on chromosome 19q, had a maximum multipoint lod score (MLS) of 2.6.

CONCLUSIONS

Our study provides evidence for the locations of genes predisposing to IA. Further studies are necessary to elucidate the genes and their role in the pathophysiology of IA, and to design genetic tests.

Proteinuria and prenatal diagnosis of congenital nephrosis in fetal carriers of nephrin gene mutations

High concentrations of alpha-fetoprotein (AFP) are used for prenatal diagnosis of the Finnish type of congenital nephrotic syndrome (NPHS1). We investigated the validity of this test. We retrospectively established fetal NPHS1 genotype and assessed renal pathology in 21 pregnancies that had been terminated because of raised concentrations of AFP in amniotic fluid. 12 fetuses were homozygous and nine were heterozygous (carriers) for NPHS1 mutations. Raised concentrations of AFP and similar proteinuric features in fetal kidneys were seen in both groups, indicating that these signs are unreliable for prenatal diagnosis of congenital nephrosis. We strongly recommend the use of mutation analysis of the NPHS1 gene to confirm the AFP results in prenatal diagnosis of NPHS1.

Missense mutations in GJB2 encoding connexin-26 cause the ectodermal dysplasia keratitis-ichthyosis-deafness syndrome

Keratitis-ichthyosis-deafness syndrome (KID) is a rare ectodermal dysplasia characterized by vascularizing keratitis, profound sensorineural hearing loss (SNHL), and progressive erythrokeratoderma, a clinical triad that indicates a failure in development and differentiation of multiple stratifying epithelia. Here, we provide compelling evidence that KID is caused by heterozygous missense mutations in the connexin-26 gene, GJB2. In each of 10 patients with KID, we identified a point mutation leading to substitution of conserved residues in the cytoplasmic amino terminus or first extracellular domain of Cx26. One of these mutations was detected in six unrelated sporadic case subjects and also segregated in one family with vertical transmission of KID. These results indicate the presence of a common, recurrent mutation and establish its autosomal dominant nature. Cx26 and the closely related Cx30 showed differential expression in epidermal, adnexal, and corneal epithelia but were not significantly altered in lesional skin. However, mutant Cx26 was incapable of inducing intercellular coupling in vitro, which indicates its functional impairment. Our data reveal striking genotype-phenotype correlations and demonstrate that dominant GJB2 mutations can disturb the gap junction system of one or several ectodermal epithelia, thereby producing multiple phenotypes: nonsyndromic SNHL, syndromic SNHL with palmoplantar keratoderma, and KID. Decreased host defense and increased carcinogenic potential in KID illustrate that gap junction communication plays not only a crucial role in epithelial homeostasis and differentiation but also in immune response and epidermal carcinogenesis.

Maternal serum beta-HCG and alpha-fetoprotein concentrations in singleton pregnancies following assisted reproduction

BACKGROUND

The reason for the elevated levels of HCG in assisted reproduction pregnancies remains unknown. Our hypothesis was that this increase is caused by the ovarian superovulation therapy.

METHODS

We compared the beta-HCG and alpha-fetoprotein (AFP) multiples of the median (MoM) in singleton pregnancies after IVF or ICSI with those achieved by frozen embryo transfer (FET) in spontaneous cycles.

RESULTS

The HCG and AFP MoMs (plus minus SEMs) of 59 FET pregnancies were compared with 144 IVF (including 48 ICSI) pregnancies. The maternal HCG of pregnancies following ovarian stimulation was 1.31 plus minus 0.08 MoM compared with 1.35 plus minus 0.12 MoM in the unstimulated ones. The values for AFP were 1.06 plus minus 0.05 versus 1.11 plus minus 0.05 respectively. No significant differences could be observed between pregnancies following stimulated IVF/ICSI and unstimulated FET cycles.

CONCLUSIONS

Our results show that second trimester maternal serum HCG is also elevated in singleton pregnancies following spontaneous FET cycles. The increased maternal serum HCG in IVF pregnancies is thus not related to superovulation therapy. Because of the elevated maternal serum HCG levels, serum screening cannot be performed reliably in pregnancies following assisted reproduction technology. Ultrasonographic detection of the nuchal translucency is unaffected and should be used for this group of women undergoing assisted reproduction.

Maternal serum human chorionic gonadotrophin and pregnancy-associated plasma protein A in twin pregnancies in the first trimester

OBJECTIVES

To determine the levels of free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A) in twin pregnancies in the first trimester.

METHODS

Serum samples were obtained from 67 pregnant women with twin pregnancies and maternal serum free beta-hCG and PAPP-A concentrations were compared with those of 4279 singleton controls between the 8th and 13th weeks of gestation.

RESULTS

The geometric means of chromosomally normal twin pregnancies were 1.85 MoM for free beta-hCG and 2.36 MoM for PAPP-A. There were no cases affected by Down syndrome in either group.

CONCLUSION

Twin pregnancies secrete more PAPP-A than expected on the basis of singleton controls whereas free beta-hCG production is not increased. The results of the present study can be used to establish normal reference values when introducing first trimester Down syndrome screening in prenatal care.

Genome-wide linkage disequilibrium mapping of late-onset Alzheimer's disease in Finland

BACKGROUND

AD is a complex neurodegenerative disorder comprising several disease-associated chromosome loci. To find novel susceptibility genes for late-onset AD, a population-based genome-wide search using linkage disequilibrium (LD) mapping approach has been performed.

METHOD

Forty-seven patients with late-onset AD and 51 age-matched control subjects were carefully chosen from the same geographic area in eastern Finland, where the population is descended mainly from a small group of original founders. These subjects were initially genotyped with 366 polymorphic microsatellite markers, and a follow-up analysis was performed with additional microsatellite markers for those chromosome loci found to be associated with AD.

RESULTS

Initial genome-wide screening revealed 21 chromosomal loci significantly associated with AD in addition to the 13q12 locus described previously. Subsequent comparison of single-allele frequencies of the microsatellite markers in the AD and control groups indicated the presence both of possible risk alleles (odds ratio [OR] > 1) and of possible protective alleles (OR < 1). Screening of the LD regions with additional microsatellite markers revealed seven chromosomal loci where more than one microsatellite marker was associated with AD (1p36.12, 2p22.2, 3q28, 4p13, 10p13, 18q12.1, and 19p13.3) in addition to the 13q12 locus.

CONCLUSIONS

These genome-wide LD screening data suggest that several AD-associated chromosomal loci exist, which may encompass novel susceptibility genes for late-onset AD. Therefore, extensive screening of the genes located in the vicinity of these LD regions is necessary to elucidate their role in AD.

Wide scope prenatal diagnosis at Kuopio University Hospital 1997-1998: integration of gene tests and fetal karyotyping

OBJECTIVE

To investigate the applicability of carrier screening in women undergoing invasive prenatal diagnosis.

DESIGN

Prospective study.

SETTING

University-based clinic.

PARTICIPANTS

Two hundred and fifty-six pregnant women.

METHODS

Gene tests were offered for fragile X syndrome, aspartylglycosaminuria and infantile neuronal ceroid lipofuscinosis at the time of invasive prenatal testing.

RESULTS

The overall uptake of the tests was 92%. Previously unrecognised carriership was found in 10 women: aspartylglycosaminuria (7); infantile neuronal ceroid lipofuscinosis (2) and fragile X (1). Fetal genotyping was carried out in one carrier of aspartylglycosaminuria whose partner was also a carrier, and in one woman who was found to have fragile X premutation. Both fetuses were unaffected.

CONCLUSION

Carrier screening for single-gene disorders is feasible and well accepted among pregnant women undergoing invasive prenatal testing. The major benefit is that there is no need to consider extra invasive tests when carriership is detected. Incorporation of genetic testing into fetal karyotyping gives more security to future parents.

Evaluation of first trimester maternal serum and ultrasound screening for Down's syndrome in Eastern and Northern Finland

The current trend in prenatal diagnosis is that trisomy screening is being moved to the first trimester and ultrasonographic nuchal translucency measurement is included in risk calculation. It is likely that biochemical screening in the second trimester will gradually be given up. In Eastern and Northern Finland, during the year 1999 we offered first-trimester ultrasonographic and serum screening for trisomy 21, with measurements of maternal serum PAPP-A and beta-hCG. A total of 2515 pregnant women participated in the screening, yielding the detection of eight foetuses with Down's syndrome. Six affected foetuses (75%) were detected by means of first-trimester serum screening. Since we were in the phase of collecting data for the Finnish medians for PAPP-A and beta-hCG, the women were not given the estimates of risk for trisomy 21. Only 1602 of the 2515 enrolled women had the combination of first-trimester ultrasonographic and serum screening performed, and in that group there were five foetuses with Down's syndrome. The combination ultrasonographic and serum approach yielded a Down's syndrome detection rate of 80% (four out of five) with a 5% false positive rate, whereas in nuchal translucency based-screening the detection rate was 60%, with a 5% false positive rate.

Antenatal genetic screening for congenital nephrosis

This study was undertaken to study the applicability of genetic antenatal screening for the Finnish type of congenital nephrosis (CNF), which is a recessive disorder leading to nephrotic syndrome from birth. At Kuopio University Hospital, a total of 1303 pregnant women were offered carrier screening for CNF at the time of first trimester nuchal fold translucency measurement when fetally derived alpha-fetoprotein is still produced by the yolk sac. Two mutations of the nephrin (NPHS 1) gene, accounting for approximately 95% of affected alleles, were tested by two PCR tests. Uptake of the gene test was 91.0% (n=1183). Altogether 38 female carriers were found; a population carrier frequency of 1 in 31. Their partners were tested and two of them were also found to be carriers. In these two pregnancies invasive prenatal diagnosis was offered and accepted, and the results indicated one carrier and one affected fetus. Carrier screening is an effective and well-accepted method for antenatal screening for fetal CNF. Direct mutation analysis involves markedly less invasive procedures compared with serum alpha-fetoprotein (AFP) screening, and the diagnosis was clear-cut. The results indicate that in single-gene disorders genetic testing is suitable for antenatal screening.

Multiple founder effects and geographical clustering of BRCA1 and BRCA2 families in Finland

In the Finnish breast and ovarian cancer families six BRCA1 and five BRCA2 mutations have been found recurrently. Some of these recurrent mutations have also been seen elsewhere in the world, while others are exclusively of Finnish origin. A haplotype analysis of 26 Finnish families carrying a BRCA1 mutation and 20 families with a BRCA2 mutation indicated that the carriers of each recurrent mutation have common ancestors. The common ancestors were estimated to trace back to 7-36 generations (150-800 years). The time estimates and the geographical clustering of these founder mutations in Finland are in concordance with the population history of this country. Analysis of the cancer phenotypes showed differential ovarian cancer expression in families carrying mutations in the 5' and 3' ends of the BRCA1 gene, and earlier age of ovarian cancer onset in families with BRCA1 mutations compared with families with BRCA2 mutations. The identification of prominent and regional BRCA1 and BRCA2 founder mutations in Finland will have significant impact on diagnostics in Finnish breast and ovarian cancer families. An isolated population with known history and multiple local founder effects in multigenic disease may offer distinct advantages also for mapping novel predisposing genes.

Pregnancy outcome in carriers of fragile X

OBJECTIVE

To evaluate pregnancy outcome in women who are carriers of fragile X.

DESIGN

Cross-sectional case-control study.

SETTING

Department of Obstetrics and Gynaecology, Kuopio University Hospital, Finland.

SAMPLE

Sixty-three singleton pregnancies in carriers of fragile X who were referred for genetic counselling and prenatal diagnosis to Kuopio University Hospital.

METHODS

Logistic regression analysis was used to compare pregnancy outcome in women who are fragile X carrier with outcome of the general obstetric population.

RESULTS

Carriers of fragile X often experienced more bleeding in late pregnancy than did the reference group. Otherwise, the course and outcome of pregnancy were comparable in both groups.

CONCLUSION

Pregnancy outcome in women who are carriers of fragile X is favourable. There is no need to initiate special fetal monitoring because of the fragile X status of the woman.

Prenatal diagnosis of fragile X syndrome and the risk of expansion of a premutation

The aim of the present study was to evaluate prospectively the dynamics of the FMR1 gene. The risk of full mutation among pregnant women and the carriers, and the risk of expansion of a premutation allele to a full mutation were estimated. We identified 89 pregnant women with an expanded FMR1 gene seeking prenatal diagnosis. Amniocentesis or chorion villus sampling (CVS) was offered and a DNA test of the FMR1 gene was carried out in such pregnancies. The overall risk of full mutation among women (N = 21) with a repeat size between 60 and 80 was 4.8% (one fetus with mosaicism), and the risk of expansion of the premutation allele to a full mutation was 14% in those offspring to whom the premutation allele was transmitted. The risk of full mutation among the carriers (N = 13) with a repeat size between 81 and 100 was 61.5% (8/13), and the risk of expansion of a premutation allele to a full mutation was 89%. Only one case fell into the category of 101-200 repeats, and expansion to a full mutation was recorded. Fetuses of full mutation mothers inherited the larger allele in 64% (14/22) of the cases. The range of 40-59 repeats was safe: there were no fetal full mutations. The risk of full mutation was also low among the subjects with a repeat size between 60 and 80, whereas the risk increased significantly after 80 repeats. Maternal premutation size was positively correlated with the risk of having a full mutation offspring.

Does apolipoprotein E genotype relate to BMD and bone markers in postmenopausal women?

OBJECTIVES

Bone mineral density (BMD) and development of osteoporosis are partly determined by genetic factors. The associations between one of suggested candidate, apolipoprotein E (apo E) genotype to bone mineral density (BMD) and bone biochemical markers was studied in 464 subjects recruited from a population-based group of early postmenopausal women (n = 13100). Additionally, the influence of apo E genotype on BMD changes during a 5-year follow-up with or without hormone replacement therapy (HRT) was investigated.

METHODS

Participants were randomized into two treatment groups: HRT group: Sequential combination of 2 mg estradiol valerate and 1 mg cyproterone acetate with or without vitamin D3, 100-300 IU/day + calcium lactate, 500 mg/day (n = 232), and the non-HRT group: Calcium lactate, 500 mg/day alone or in combination with vitamin D3, 100-300 IU/day (n = 232). BMD was measured from the lumbar spine and proximal femur at baseline and after 5 years of treatment (n = 352). In a subgroup (n = 59), the serum concentrations of bone biochemical markers (intact osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and type I collagen carboxy-terminal telopeptide (ICTP)) were measured at baseline and after 1 year of follow-up.

RESULTS

At baseline, the BMDs were similar between the five apo E genotype groups (2/3, 2/4, 3/3, 3/4, 4/4). No significant differences in lumbar or femoral neck BMDs of women with the apo E4 allele were found compared with those without it. There was a statistically significant difference in 5-year BMD changes between the HRT and non-HRT groups. After 5 years, the BMD of the femoral neck had remained constant and the mean lumbar spine BMD had increased by 1.5% in the HRT group, whereas both BMDs had decreased by 4-5% in the non-HRT group. However, the apo E genotype did not modify the changes in BMD in either group. Additionally, the baseline concentrations of bone metabolic markers and their 1-year changes showed no genotype-related associations.

CONCLUSIONS

The results of our population-based study indicate that apo E genotype does not modify lumbar or femoral neck BMDs or serum bone biochemical markers or their response to HRT in early postmenopausal Caucasian women.

Is the presenilin-1 E318G missense mutation a risk factor for Alzheimer's disease?

Nearly all of the presenilin-1 (PSEN-1) mutations are missense mutations leading to Alzheimer's disease (AD). The role of the mutation E318G (a substitution of glutamic acid to glycine) in the PSEN-1 is controversial. It has been found both in AD patients and in non-demented control individuals. Using the polymerase chain reaction and the restriction fragment length polymorphism method, we screened for E318G mutation in a total of 16 familial (FAD) cases, in 64 sporadic neuropathologically confirmed AD cases and in 270 non-demented controls including 35 neuropathologically confirmed individuals. We detected the E318G mutation in four FAD cases, seven sporadic AD cases and 10 control individuals with highly varying onset-ages. Odds ratios for carrying the mutation were 7.6 and 3 in FAD and sporadic AD cases, respectively. Our results suggest that this mutation could be a risk factor in the Finnish FAD and sporadic AD population. It may be in linkage disequilibrium with a pathogenic change somewhere else in the PSEN-1 gene or in close proximity to the PSEN-1 gene.

Etiology and outcome of second trimester non-immunologic fetal hydrops

BACKGROUND

This investigation was undertaken to study the conditions resulting in midtrimester fetal hydrops and to evaluate its overall prognosis as regards counseling purposes.

MATERIAL AND METHODS

The etiology of midtrimester non-immune fetal hydrops was retrospectively evaluated as regards cases detected in singleton pregnancies (n=58) from January 1987 through December 1996. The condition was diagnosed by way of routine biochemical and ultrasonographic screening of a pregnant population.

RESULTS

The rate of diagnosed midtrimester fetal hydrops was 1 in 1700 pregnancies and the overall survival rate in this usually unexpected condition was less than 10%. Various chromosomal and fetal structural abnormalities dominated as a cause of fetal hydrops, representing 44.8% and 43.1% of the cases, respectively. Infection caused only 6.9%. The underlying etiology remained unknown in only three cases. However, in 78% the diagnosis was already known prenatally.

DISCUSSION

Although the overall prognosis is poor, knowledge of the primary etiology is important to determine a rational therapeutic strategy. If the results of routine investigations rule out malformation and abnormal chromosomes, follow-up serial ultrasonographic assessment may indicate that the hydropic state is transient, carrying a somewhat better prognosis.

Linkage disequilibrium in the 13q12 region in Finnish late onset Alzheimer's disease patients

Alzheimer's disease (AD) is a complex neurodegenerative disorder, for which several disease-associated loci have been located on different chromosomes. We have used a population-based linkage disequilibrium mapping approach in order to find potential AD-associated loci on chromosome 13. To avoid population stratification, late onset AD patients and age-matched controls were carefully chosen from the same geographical area in Eastern Finland, where the population is mainly descended from a small group of original founders. During the initial screening with chromosome 13-specific microsatellite markers, tetranucleotide marker D13S787 was found to be in linkage disequilibrium in the 13q12 region. Screening this region with additional microsatellite markers revealed that marker D13S292 was also significantly associated with AD. Stratification of the AD patients and controls into groups according to apolipoprotein E, sex, and familial/sporadic status indicated that the 13q12 locus was associated with female familial AD patients regardless of ApoE genotype. Based on the physical data from the region 13q12, markers D13S292 and D13S787 were estimated to reside in a 810kb long YAC clone 754h7 together with two infant brain-derived ESTs and the H,K-ATPase alpha-subunit protein gene (ATP1AL1). The localisation of these sequences at the linkage disequilibrium region suggests that they may be candidate genes involved in a sex-specific effect during development of AD.

Promoter polymorphism (-491A/T) in the APOE gene of Finnish Alzheimer's disease patients and control individuals

Apolipoprotein E (APOE) epsilon4 allele is a major risk factor for the development of Alzheimer's disease (AD). It has been suggested that the quantitative expression of APOE alleles results from mutations in the promoter region of this gene. We studied the -491A/T promoter polymorphism and whether it is dependent on the APOE epsilon4 allele in clinic-based AD (n = 106) and community-based control (n = 123) samples. The -491A/T and APOE polymorphisms were analyzed using the polymerase chain reaction method and restriction fragment length polymorphism analysis. The APOE epsilon4 allele was strongly associated with AD when compared with controls, P < 0.001 (odds ratio 5.85, 95% CI 3.29- 10. 41). The genotype distribution of the -491A/T polymorphism did not significantly differ between the study groups (P = 0.063), and the -491A allele was not associated with any significant risk in the AD group when compared to controls (odds ratio 1.82, 95% CI 0.95-3.49). However, haplotype estimation analysis indicated linkage disequilibrium between APOE -491A/T polymorphism and the APOE epsilon4 allele. Our findings confirm APOE polymorphism still to be the most efficient predictor of risk in AD.

Unexplained elevated serum hCG is associated with raised amniotic fluid erythropoietin levels in second-trimester pregnancies

OBJECTIVE

This study was designed to investigate the association between the concentrations of maternal serum hCG and amniotic fluid erythropoietin during the second trimester of pregnancy.

METHODS

In a prospective case-control study, 42 consecutive singleton pregnancies showing unexplained elevated serum hCG concentrations (>2.0 multiples of the median, MoM) in Down's syndrome screening and 27 control pregnant women undergoing midtrimester amniocentesis because of a previous cytogenetic abnormality were studied.

RESULTS

The mean amniotic fluid erythropoietin concentration in the study group was 1.8 (range 0.61-8.7) MoM, whereas it was 1.1 (range 0.71-3. 96) MoM in the controls (p = 0.035). A significantly increasing relationship (p < 0.05) was found between the concentrations of maternal serum hCG and amniotic fluid erythropoietin.

CONCLUSIONS

The results of the current study revealed in vivo the association between elevated hCG and amniotic fluid erythropoietin levels which, in turn, supports the concept of early placental damage. The underlying pathology seems to be sufficient to cause an erythroblastic response.

The effects on fetal development of high alpha-fetoprotein and maternal smoking

OBJECTIVES

This study determined the risk of impaired fetal growth resulting from the interaction between maternal smoking during pregnancy and unexplained elevated concentrations of maternal serum alpha-fetoprotein (MSAFP).

METHODS

This observational study involved 123 pregnant smokers with unexplained second-trimester elevated concentrations of MSAFP, 827 smokers with normal levels, and 471 nonsmokers with raised levels.

RESULTS

By logistic regression, coincident smoking and elevated MSAFP levels were found to be associated with increases in the low basic risks of prematurity, small-for-gestational-age births, low birthweight, and need for neonatal care.

CONCLUSIONS

Maternal smoking has an adverse effect on fetal development in pregnancies with unexplained elevated MSAFP concentrations. Such pregnancies merit close surveillance.

Participation in prenatal screening tests and intentions concerning selective termination in Finnish maternity care

AIMS

The study examined how prenatal screening tests are presented to women, factors associated with women's participation in screening, their experience of decision-making and intentions concerning pregnancy termination, and hospital data on rates of selective terminations.

METHODS

Questionnaires were given to pregnant women visiting maternity centres in two Finnish towns in which serum screening was offered (n = 1,035) and in one town where midtrimester ultrasound screening was offered (n = 497). Response rates to the questionnaires were 88 and 85%, respectively. Other questionnaires asking about selective terminations following detected fetal disorders were sent in 1993 to all public hospitals with obstetrics or gynaecology departments (response rate 100%).

RESULTS

The serum screening test had usually been offered to women as a free choice, but for 22% of them it was presented as a routine procedure. Most women (92%) underwent serum screening and most (86%) found the decision to participate or not easy. In almost every aspect of presentation and participation studied, serum and ultrasound screening differed from each other. 85% of respondents to ultrasound screening answered that it was offered as a routine procedure. Close acquaintance with a person with congenital disability was negatively associated with participation in serum screening and with the intention to terminate pregnancy in case of a detected disability. 27% of women in the serum screening survey and 22% in the ultrasound survey declared that they would have declined pregnancy termination if a fetal disorder had been detected. However, according to the hospitals' data, only 13% of pregnancies with a serious fetal disorder detected were continued.

CONCLUSIONS

All prenatal screening tests, including ultrasound examinations, require an adequate process of informed consent. Because the aim of such tests is to detect fetal malformations and syndromes, health care professionals should discuss the implications with women before they decide. Because acquaintance with a disabled person was found to associate with participation in screening and with intentions about selective termination, women's perceptions of lives of the disabled should receive more attention in future studies.

Is the response of serum lipids and lipoproteins to postmenopausal hormone replacement therapy modified by ApoE genotype?

Postmenopausal hormone replacement therapy (HRT) has favorable effects on the serum lipid profile, and it also decreases the risk of cardiovascular diseases. The apolipoprotein E genotype has influence on serum levels of lipids and lipoproteins; apoE allele epsilon4 (apoE4) is associated with high total and LDL cholesterol levels. Genotype also influences the lipid responses to treatment with diet and statins, but the effect of HRT in different apoE genotypes is unknown. We studied the effects of HRT on the concentrations of serum lipids in apoE4-positive early postmenopausal women (genotypes 3/4 and 4/4) compared with apoE4-negative women (genotypes 2/3 and 3/3) in a population-based, prospective 5-year study. In all, 232 early postmenopausal women were randomized into 2 treatment groups: an HRT group (n=116), which received a sequential combination of 2 mg estradiol valerate (E2Val) from day 1 to 21 and 1 mg cyproterone acetate (CPA) from day 12 to 21 (Climen), and a placebo group (n=116), which received 500 mg/d calcium lactate. Serum concentrations of total, LDL, and HDL cholesterol and triglycerides were measured at baseline and after 2 and 5 years of treatment. A total of 154 women completed the final analysis. During the follow-up period, serum total cholesterol and LDL cholesterol concentrations decreased in the HRT group in apoE4-negative women (8.1% and 17.1%, respectively; P<0.001) but did not change in the HRT group in apoE4-positive women or in the placebo group. Serum HDL cholesterol concentrations decreased in the placebo group (apoE4-negative, 3.9%, P=0.015; apoE4-positive, 8.1%, P=0.004) but did not change significantly in the HRT group. Serum triglyceride levels tended to increase in both study groups and genotypes (15.1% to 36.2%, P<0.038 to 0.001), but no differences were observed between the study groups or genotypes, respectively. Our finding was that in postmenopausal Finnish women LDL cholesterol levels in apoE4-negative subjects respond more favorably to HRT than those in apoE4-positive subjects. This finding has potential importance in postmenopausal women with hypercholesterolemia, if confirmed in other studies.

Feasibility and acceptance of screening for fragile X mutations in low-risk pregnancies

Fragile X syndrome is the second leading cause of mental retardation after Down syndrome. Most women carriers of the fragile X mutation are unaware of their condition. We critically evaluated whether screening pregnant women at low risk for FMR1 mutation would be feasible as a routine part of antenatal care in general practice. We also studied acceptance and attitudes to gene testing. From July 1995 until December 1996, a carrier test was offered at the Kuopio City Health Centre free of charge to all pregnant women in the first trimester following counselling given by midwives on fragile X syndrome. All women found to be carriers of FMR1 gene mutations underwent detailed genetic counselling and were offered prenatal testing. Attitudes towards the gene test were elicited by questionnaire. Most pregnant women (85%) elected to undertake the gene test. Six women were found to be carriers (a rate of 1 in 246), and all subsequently accepted prenatal testing. Three foetuses had a normal FMR1 gene, one had a large premutation, one a 'size mosaic' mutation pattern, and another a full mutation. This observational and interventional study demonstrates that antenatal screening provides an effective way of identifying carriers and incorporating prenatal testing into this process.