Attitudes toward prenatal screening and testing for Fragile X

Maternal FMR1 alleles expansion in newborns during transmission: a prospective cohort study

INTRODUCTION

The CGG repeats in the 5' untranslated region of the fragile X mental retardation 1 gene (FMR1) gene shows increased instability upon maternal transmission. Maternal FMR1 intermediate (45-54 repeats) and premutation (PM: 55-<200 repeats) alleles usually expand to full mutation (>200 repeats) alleles in offspring and consequently, cause fragile X syndrome (FXS) in them.

METHODS

In a prospective cohort study, Pakistani pregnant women in prenatal care were first screened for FMR1 expanded alleles. In the follow-up, pregnancy outcomes in women carrying FMR1 expanded alleles were recorded and their newborn offspring were also screened for FXS.

RESULTS

In a total of 1950 pregnant women, 89 (4.6%) were detected carriers for FMR1 expanded alleles; however, rates of detection of expanded alleles were found significantly high in women with a history of FXS. In addition, miscarriages and birth of affected newborns with FXS were significantly more common in women carrying large size PM alleles and had a history of FXS (P = 0.0494 and P = 0.0494, respectively).

CONCLUSIONS

The current study provides the first evidence of screening Pakistani pregnant women for FMR1 expanded alleles in prenatal care. Moreover, the miscarriage was also detected as a clinical predictor for FXS.

IMPACT

Offspring would have a higher risk of developing FXS due to maternal FMR1 alleles expansions during transmission. This is the first prospective cohort study in Pakistan for finding FMR1 allelic status of pregnant women and their newborn offspring in follow-up. The robust offspring risk for FXS estimated in this study may be valuable information for genetic counseling of women carriers for FMR1 expanded alleles. The family history and miscarriage were detected as effective indicators for FXS carrier screening in Pakistani women.

Attitudes toward population screening among people living with fragile X syndrome in the UK: 'I wouldn't wish him away, I'd just wish his fragile X syndrome away'

In an age of expanded genetic screening, fragile X syndrome is increasingly considered a candidate condition, given its prevalence, the absence of curative interventions, and its impact on families. However, relatively little research has explored the views of families and people living with fragile X syndrome toward population screening. This study reports on in-depth interviews with 19 participants: 3 with people diagnosed with a fragile X condition (fragile X syndrome = 2, FXTAS = 1) and 16 people with fragile X syndrome in their family (11 parents, 2 grandparents, 1 spouse, 1 sibling, and 1 aunt) living in the UK. This study reveals the complexity of attitudes within this group and the existence of genuine ambivalence toward different population screening programs. While the overwhelming majority believed that preconception and newborn genetic screening should be made available to the general public, the notion of prenatal screening was far more controversial, with only five participants expressing support for such a program. Expressivist concerns were highlighted equally both by those who supported prenatal screening, as by also those who did not. Participants who supported prenatal screening drew clear distinctions between people with fragile X syndrome and the condition itself, in order to neutralize expressivist concerns and existential threat. However, for others, this division was challenging to maintain. Impairment effects associated with fragile X syndrome, more specifically, its implications for behavior, intellect, and personality, made it harder for some participants to conceptually separate the person from their condition. This study concludes that screening remains a complex issue for families living with genetic conditions and that expressivist concerns affect, and are managed by, families living with different types of disability in contrasting ways. Screening for conditions that affect personality, behavior, and intellect produces unique iterations of expressivism, identity, and stigmatization that families produce specific, and creative, strategies to navigate.

Fragile X syndrome carrier screening accompanied by genetic consultation has clinical utility in populations beyond those recommended by guidelines

Background

Fragile X syndrome (FXS) is the most common inherited form of intellectual disability. Many providers offer preconception or prenatal FXS carrier screening. However, guidelines recommend screening only for those with a family history or undergoing fertility evaluation. Wider screening has been resisted because of concerns about patient understanding of FXS‐associated inheritance patterns and phenotypes. Additionally, the clinical utility has been questioned.

Methods

We addressed these concerns by analyzing reproductive decision‐making and pregnancy management informed by post‐test genetic consultation among 122 FMR1 premutation carriers identified by expanded carrier screening.

Results

Sixty‐three percent of those screened met guidelines screening criteria; the remaining 37% did not. Ninety‐eight percent had undergone post‐test genetic consultation. Of respondents screened preconceptionally, 74% reported planning or pursuing actions to reduce the risk of an affected pregnancy; the extent to which couples planned/pursued these actions was not significantly different between those meeting either screening criterion (76%) versus those meeting neither criterion (55%). Of respondents screened prenatally, 41% pursued prenatal diagnostic testing; the extent to which couples pursued prenatal diagnosis was not significantly different between those who met either screening criterion (37%) versus those who met neither criterion (31%).

Conclusion

These results support the expansion of FXS screening criteria in guidelines.

"I didn't take it too seriously because I'd just never heard of it": Experiential knowledge and genetic screening for thalassaemia in the UK

Members of the public face particular challenges when undergoing reproductive genetic screening. Lack of family history with genetic disease has been identified as a key barrier affecting screening uptake and responses to genetic risk. This study explores this obstacle using beta thalassaemia as a case study. Fifteen in-depth qualitative interviews were conducted exploring the reproductive views and decisions of people at risk of transmitting thalassaemia. Eleven participants had thalassaemia themselves and/or were members of an affected family. Four participants were identified as thalassaemia carriers through genetic screening programmes with no family history. Notable differences were observed between these two groups. For thalassaemic individuals and families, past experience clarified and facilitated their sense of reproductive responsibility, however carriers struggled to relate to, and incorporate the information into their lives. It was witnessing their child becoming symptomatic-rather than receiving a diagnosis or genetic risk information per se that had the most substantial influence on carriers' subsequent views and decisions. Educational resources used to support genetic screening programmes would benefit from an engagement with the experiential accounts of life with genetic disease in order to more effectively bridge the chasm in knowledge and understanding between affected families and the general public, towards whom expansive genetic screening is aimed.

Informed decision making and psychosocial outcomes in pregnant and nonpregnant women offered population fragile X carrier screening

PurposePopulation-based carrier screening for fragile X syndrome (FXS) is still not universally endorsed by professional organizations due to concerns around genetic counseling for complex information and potential for psychosocial harms.MethodsWe determined uptake levels, decision making, and psychosocial impact in a prospective study of pregnant and nonpregnant Australian women offered FXS carrier screening in clinical settings. Women received pretest genetic counseling, and completed questionnaires when deciding and one month later.ResultsOf 1,156 women recruited, 83.1% returned the first questionnaire with 70.6% nonpregnant and 58.8% pregnant women choosing testing (χ²=16.98, P<0.001). Overall, informed choice was high in both nonpregnant (77.4%) and pregnant (72.9%) women (χ²=0.21, P=0.644), and more tested (76.0%) than not-tested (66.7%) women (χ²=6.35, P=0.012) made an informed choice. Measures of depression, stress, and anxiety were similar to population norms for ~85% of women. Decisional conflict and regret were generally low; however, decisional uncertainty and regret were greater in pregnant than nonpregnant women, and not-tested than tested women (uncertainty: χ²=18.51, P<0.001 and χ²=43.11, P<0.001, respectively; regret: χ²=6.61, P<0.037 and χ²=35.54, P<0.001, respectively).ConclusionWe provide evidence to inform guidelines that population FXS carrier screening can be implemented with minimal psychosocial harms following appropriate information and prescreening genetic counseling.

Responsible implementation of expanded carrier screening

This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.

"It gives them more options": preferences for preconception genetic carrier screening for fragile X syndrome in primary healthcare

This study aims to explore stakeholder views about offering population-based genetic carrier screening for fragile X syndrome. A qualitative study using interviews and focus groups with stakeholders was undertaken to allow for an in-depth exploration of views and perceptions about practicalities of, and strategies for, offering carrier screening for fragile X syndrome to the general population in healthcare settings. A total of 188 stakeholders took part including healthcare providers (n = 81), relatives of people with fragile X syndrome (n = 29), and members of the general community (n = 78). The importance of raising community awareness about screening and providing appropriate support for carriers was emphasized. There was a preference for preconception carrier screening and for providing people with the opportunity to make an informed decision about screening. Primary care was highlighted as a setting which would ensure screening is accessible; however, challenges of offering screening in primary care were identified including time to discuss screening, knowledge about the test and possible outcomes, and the health professionals' approach to offering screening. With the increasing availability of genetic carrier tests, it is essential that research now focuses on evaluating approaches for the delivery of carrier screening programs. Primary healthcare is perceived as an appropriate setting through which to access the target population, and raising awareness is essential to making genetic screening more accessible to the general community.

Similar prevalence of expanded CGG repeat lengths in the fragile X mental retardation I gene among infertile women and among women with proven fertility: a prospective study

PURPOSE

We sought to determine the usefulness of fragile X mental retardation 1 (FMR1) carrier testing among young infertile women with or without signs of ovarian insufficiency as compared with fertile women.

METHODS

Three cohorts of women were recruited to determine the cytosine-guanine-guanine (CGG) repeats trinucleotide repeat length in the 5'-untranslated region of the FMR1 gene in lymphocyte DNA. A total of 199 fertile women, who were reported to have conceived within 3 months, were recruited together with 372 infertile women with ongoing menstrual cycles and 48 infertile women with primary ovarian insufficiency. The various ranges of FMR1 CGG repeat lengths among infertile women were compared with those of fertile controls. In infertile women with ongoing menstrual cycles, the serum concentrations of follicle-stimulating hormone, anti-Muellerian hormone, and inhibin B were measured during the early follicular phase.

RESULTS

None of the three categories of FMR1 CGG repeat length expansions (premutation, intermediate range, and high normal range) were more prevalent among infertile women than among fertile women. The CGG repeat length was not correlated with any of the ovarian reserve parameters.

CONCLUSION

In comparison with a generalized preconception screening strategy, infertility as a criterion, even together with reduced ovarian reserve, is not suitable for identifying a higher proportion of women with expanded FMR1 CGG repeat length.

Offering fragile X syndrome carrier screening: a prospective mixed-methods observational study comparing carrier screening of pregnant and non-pregnant women in the general population

INTRODUCTION

Fragile X syndrome (FXS) is the leading cause of inherited intellectual and developmental disability. Policy development relating to carrier screening programmes for FXS requires input from large studies examining not only test uptake but also psychosocial aspects. This study will compare carrier screening in pregnant and non-pregnant populations, examining informed decision-making, psychosocial issues and health economics.

METHODS AND ANALYSIS

Pregnant and non-pregnant women are being recruited from general practices and obstetric services. Women receive study information either in person or through clinic mail outs. Women are provided pretest counselling by a genetic counsellor and make a decision about testing in their own time. Data are being collected from two questionnaires: one completed at the time of making the decision about testing and the second 1 month later. Additional data are gathered through qualitative interviews conducted at several time points with a subset of participating women, including all women with a positive test result, and with staff from recruiting clinics. A minimum sample size of 500 women/group has been calculated to give us 88% power to detect a 10% difference in test uptake and 87% power to detect a 10% difference in informed choice between the pregnant and non-pregnant groups. Questionnaire data will be analysed using descriptive statistics and multivariate logistic regression models. Interview data will be thematically analysed. Willingness-to-pay and cost effectiveness analyses will also be performed. Recruitment started in July 2009 and data collection will be completed by December 2013.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Universities of Melbourne and Western Australia and by recruiting clinics, where required. Results will be reported in peer-reviewed publications, conference presentations and through a website http://www.fragilexscreening.net.au. The results of this study will make a significant contribution to discussions about the wider introduction of population carrier screening for FXS.

Newborn screening and cascade testing for FMR1 mutations

We describe an ongoing pilot project in which newborn screening (NBS) for FMR1 mutations and subsequent cascade testing are performed by the MIND Institute at the University of California, Davis Medical Center (UCDMC). To date, out of 3,042 newborns initially screened, 44 extended family members have been screened by cascade testing of extended family members once a newborn is identified. Fourteen newborns (7 males and 7 females) and 27 extended family members (5 males and 22 females) have been identified with FMR1 mutations. Three family histories are discussed in detail, each demonstrating some benefits and risks of NBS and cascade testing for FMR1 mutations in extended family members. While we acknowledge inherent risks, we propose that with genetic counseling, clinical follow-up of identified individuals and cascade testing, NBS has significant benefits. Treatment for individuals in the extended family who would otherwise not have received treatment can be beneficial. In addition, knowledge of carrier status can lead to lifestyle changes and prophylactic interventions that are likely to reduce the risk of late onset neurological or psychiatric problems in carriers. Also with identification of carrier family members through NBS, reproductive choices become available to those who would not have known that they were at risk to have offspring with fragile X syndrome.

"It's about having the choice": stakeholder perceptions of population-based genetic carrier screening for fragile X syndrome

This project explored, the views of key stakeholders regarding population-based genetic carrier screening for fragile X syndrome (FXS). Interviews and focus groups were conducted with healthcare providers, relatives of individuals with FXS and members of the general population. Data were transcribed verbatim and coded into themes. 188 individuals took part in this study. Perceived benefits of carrier screening included: learning the risk of having a child with FXS; learning the risk of fragile X-associated primary ovarian insufficiency; and the opportunity for carriers to access reproductive options. Concerns included: the emotional impact of screening and receiving a carrier result; the predictive testing nature of the carrier test with respect to fragile X-associated tremor/ataxia syndrome; potential confusion created by receiving an intermediate result; and implications of genetic screening for society. Overall, population-based genetic carrier screening was perceived to be acceptable provided it is optional and offered at an appropriate stage of life. With the support of the participants to promote individual choice by offering a population-based carrier screening program for FXS, it is essential to carefully consider how screening might be offered in order to ensure broad accessibility and facilitation of decision-making.

Carrier screening in preconception consultation in primary care

Discussing carrier screening during preconception consultation in primary care has a number of advantages in terms of promoting autonomy and enabling the greatest range of reproductive choices. For those with a family history of an inherited condition, this ought to be a routine discussion; however, this can be expanded to include the wider population, especially for those conditions for which carrier frequencies are considered relatively common. There is published literature from around the world regarding experiences with carrier screening in primary care for cystic fibrosis, haemoglobinopathies, fragile X syndrome, Tay-Sachs disease and spinal muscular atrophy, although many of these have tended to focus on consultations during rather than before pregnancy. Overall, these studies reveal that population carrier screening is well received by the participants with apparent minimal psychosocial harms; however, challenges exist in terms of approaches to ensure couples receive adequate information to make personally relevant decisions and for ongoing health professional engagement.

FMR1 premutation carrier frequency in patients undergoing routine population-based carrier screening: insights into the prevalence of fragile X syndrome, fragile X-associated tremor/ataxia syndrome, and fragile X-associated primary ovarian insufficiency in the United States

PURPOSE

Fragile X syndrome is caused by expansion and methylation of a CGG tract in the 5' untranslated region of the FMR1 gene. The estimated frequency of expanded alleles (≥55 repeats) in the United States is 1:257-1:382, but these estimates were not calculated from unbiased populations. We sought to determine the frequency of fragile X syndrome premutation (55-200 repeats) and full mutation (>200 repeats) alleles in nonselected, unbiased populations undergoing routine carrier screening for other diseases.

METHODS

A previously validated laboratory-developed test using triplet-primed polymerase chain reaction was used to detect premutation and full mutation alleles in an unselected series of 11,759 consecutive cystic fibrosis carrier screening samples and 2011 samples submitted for screening for genetic diseases prevalent among the Ashkenazi Jewish population.

RESULTS

Premutations were identified in 48 cystic fibrosis screening samples (1:245) and 15 samples (1:134) from the Ashkenazi Jewish population. Adjusted for the ethnic mix of the US population and self-reported ethnicity in our screening population, the estimated female premutation carrier frequency in the United States was 1:178. The calculated frequency of full mutation alleles was 1:3335 overall, and the calculated premutation frequency in males was 1:400. Based on frequency of larger, ≥70 repeat alleles, and reported penetrance, the calculated fragile X-associated tremor and ataxia syndrome, and fragile X-associated primary ovarian insufficiency frequencies is 1:4848 and 1:3560, respectively.

CONCLUSION

Our calculated fragile X syndrome carrier rate is higher than previous estimates for the US population and warrants further consideration of population-based carrier screening.

Qualitative assessment of FMR1 (CGG)n triplet repeat status in normal, intermediate, premutation, full mutation, and mosaic carriers in both sexes: implications for fragile X syndrome carrier and newborn screening

PURPOSE

Fragile X syndrome is caused by expansion and subsequent methylation of a CGG trinucleotide repeat in the FMR1 5'-untranslated region. Southern blot analysis is typically required to determine expansion size for triplet repeat lengths >200. We describe a triplet-primed polymerase chain reaction-based method using automated capillary electrophoresis detection for qualitative assessment of expanded CGG repeats.

METHODS

The assay uses triplet-primed polymerase chain reaction in combination with GC-melting reagents and substitution of 7-deaza-2-deoxyGTP for dGTP. Amplicons are resolved by capillary electrophoresis.

RESULTS

A distinctive pattern of tapering or "stutter" polymerase chain reaction amplification was evident on capillary electrophoresis in male and female patients harboring all expanded allele lengths examined (up to 2000 CGG repeats) and could be used to differentiate normal, intermediate, premutation, and full mutation alleles. Full mutation alleles exhibited an additional late-migrating amplicon on capillary electrophoresis. Mixing experiments demonstrated sensitivity as low as 1% for detection of the full mutation allele. In a 1275-sample concordance study against our existing polymerase chain reaction platform (with Southern blot analysis for repeat lengths ≥55), the triplet-primed polymerase chain reaction method exhibited 100% concordance for normal, intermediate, expanded, and full mutation alleles. This method also detected the full mutation alleles in DNA isolated from blood spots.

CONCLUSION

This assay provides an accurate assessment of FMR1 repeat status and holds promise for use in carrier and newborn screening. The method distinguishes normal homozygous females from full mutation carrying females. Although the method is not useful for accurate sizing, it supplements the classic polymerase chain reaction method and results in significant reduction in the number of Southern blot analyses required to be performed in the laboratory to accurately assess the FMR1 genotype in all individuals.

A systematic review of population screening for fragile X syndrome

PURPOSE

To conduct a systematic review of literature regarding population-based screening for fragile X syndrome in newborns and women of reproductive age, either before or during pregnancy.

METHODS

Seven electronic databases were searched for English language studies published between January 1991 and November 2009. Data extraction was performed for all included studies. Results were synthesized using a narrative approach.

RESULTS

One article that examined offering newborn screening for fragile X syndrome and 10 that examined the offer of fragile X syndrome screening to women of reproductive age were identified. Two of these articles also addressed psychosocial aspects of population screening for fragile X syndrome such as attitudes to screening and experiences of screening, and a further nine addressed these issues alone. Studies exploring psychosocial issues demonstrated challenges for counseling arising from a lack of awareness or personal experience with fragile X syndrome in the general population.

CONCLUSIONS

Targeted counseling and educational strategies will be essential to support women from the general population. It is crucial that future studies offering screening for fragile X syndrome explore a range of psychosocial aspects in addition to looking at uptake of testing and mutation frequency.

A simple, high-throughput assay for Fragile X expanded alleles using triple repeat primed PCR and capillary electrophoresis

Population screening has been proposed for Fragile X syndrome to identify premutation carrier females and affected newborns. We developed a PCR-based assay capable of quickly detecting the presence or absence of an expanded FMR1 allele with high sensitivity and specificity. This assay combines a triplet repeat primed PCR with high-throughput automated capillary electrophoresis. We evaluated assay performance using archived samples sent for Fragile X diagnostic testing representing a range of Fragile X CGG-repeat expansions. Two hundred five previously genotyped samples were tested with the new assay. Data were analyzed for the presence of a trinucleotide "ladder" extending beyond 55 repeats, which was set as a cut-off to identify expanded FMR1 alleles. We identified expanded FMR1 alleles in 132 samples (59 premutation, 71 full mutation, 2 mosaics) and normal FMR1 alleles in 73 samples. We found 100% concordance with previous results from PCR and Southern blot analyses. In addition, we show feasibility of using this assay with DNA extracted from dried-blood spots. Using a single PCR combined with high-throughput fragment analysis on the automated capillary electrophoresis instrument, we developed a rapid and reproducible PCR-based laboratory assay that meets many of the requirements for a first-tier test for population screening.

Fragile X screening: attitudes of genetic health professionals

Although genetic health professionals (GHP) are major stakeholders in developing and implementing fragile X (FrX) testing and screening guidelines, their attitudes about FrX testing and population screening are virtually absent in the literature. A survey was conducted of physician geneticists (geneticists) and genetic counselors (GC). The survey addressed GHP's attitudes towards (1) prenatal FrX carrier screening; (2) pre- and full mutation screening of male and female newborns; (3) the single best time for FrX screening over the lifespan; and (4) their willingness to test a normally developing child with a positive family history. Surveys were completed by 30% (273/894) of eligible GHP. Attitudes of geneticists and GC were mostly indistinguishable. The single most favored screening approaches were (1) preconception screening targeted at women with a positive family history (43%); and (2) universal preconception screening (29%). While only 6% and 11% declared universal prenatal and universal newborn screening (NBS) as the ideal time respectively, 73% and 60% respectively would support such programs. GHP would design a NBS program to test male and female infants and to identify both pre- and full mutations. Over half would agree to order FrX testing on some normally developing children with a positive family history. In expanding FrX testing and screening to low risk individuals, GHP prefer preconception screening as the single best time. The majority also support prenatal screening and NBS. If NBS were to be introduced, GHP prefer screening to identify boys and girls with both pre- and full mutations.

Pediatricians' knowledge of and attitudes toward fragile X syndrome screening

BACKGROUND

Fragile X syndrome (FXS) screening exemplifies the challenges of screening for rare genetic conditions, including the potential to detect carriers and the lack of evidence regarding the benefit of early intervention.

OBJECTIVES

The aim of this study was to evaluate knowledge, experience, and attitudes of pediatricians toward FXS screening, either as part of newborn screening or at the 12-month well-child visit.

METHODS

Responses to survey mailings to 400 general pediatricians were analyzed.

RESULTS

The response rate was 47%. Although most (98%) reported knowing that FXS causes intellectual disability, only half (53%) knew that females could be affected and 28% knew that carriers can have health problems as adults. Only 39% reported knowing enough about FXS to discuss the condition with the family of a child who might have the condition. Most respondents (78%) believed that newborn screening for FXS would be beneficial for children and families. About half (55%) believed that parents should be offered FXS screening as part of well-child care. Few (8%) reported that they would not support FXS newborn screening or screening during well-child care because of carrier detection.

CONCLUSIONS

Among respondents there is good support for FXS newborn screening and some support for FXS screening as part of well-child care. Prior to implementing screening, efforts are needed to educate pediatricians and assess their ability to inform parents about the implications of testing and provide care after the identification of FXS or carriers. These activities can serve as a model for how to introduce other genomic tests into the primary care setting.

A targeted population carrier screening program for severe and frequent genetic diseases in Israel

A national carrier screening program targeted at communities in which severe genetic diseases are present with a frequency higher than 1/1000 live births, has been in existence in Israel since 2002. Within the communities at risk, carrier screening is voluntary whereas genetic counseling and testing is provided free of charge. During the first 5 years of the program more than 13 000 tests were performed, and at the end of 2007 it was offered in 35 different localities/communities for a total of 36 diseases. Many of the couples identified to be at risk opted for prenatal diagnosis and in two cases an affected pregnancy was terminated. In some cases the couples declined prenatal diagnosis and two of those families gave birth to an affected child. Based on the experience learnt from this targeted screening program it appears that a knowledge-based, voluntary screening program operated within the community is an effective way to provide genetic services and test referrals. The community program directed toward couples in their reproductive period does not seem to have led to stigmatization at either the individual or the community level.

A model for offering carrier screening for fragile X syndrome to nonpregnant women: results from a pilot study

PURPOSE

To develop a model of offering population carrier screening for fragile X syndrome to nonpregnant women in primary care, using a program evaluation framework.

METHODS

A three-phase approach included: (I) needs assessment exploring staff and client attitudes, and informing development of educational materials, questionnaires and protocols; (II) offering screening to women, with questionnaires at baseline (Q1) and another (Q2) 1-month later; (III) genetic counseling for test-positive women and interviews with a subgroup of participants.

RESULTS

Of 338 volunteering for Phase II, 94% completed Q1, 59% completed Q2, and 20% (N = 65) chose testing revealing one premutation carrier and three gray zone results; 31 women were interviewed. Tested women had more positive attitudes toward screening (Q1: P < 0.001; Q2: P < 0.001) compared with untested, although there was no significant difference in mean knowledge scores or anxiety. Women generally supported being offered prepregnancy screening; however, reasons against being tested included: not currently planning a family; perceiving benefits of screening as unimportant; and having to return for testing.

CONCLUSION

This is the first prospective study exploring informed decision-making for fragile X syndrome carrier screening, using a thorough process of consultation, with no apparent harms identified. It provides a model for development of future genetic screening programs.

From new screens to discovered genes: the successful past and promising present of single gene disorders

Prenatal screening for single gene disorders, which include over 10,000 diverse diseases, presents a great challenge. The major approach to identifying high-risk groups for diseases, from Tay Sachs Disease to sickle cell disease, has historically centered on ethnic-based screening. A major concern in an ethnic-based approach is that carriers belonging to less-traditionally considered populations will be missed. In the United States, the paradigm for a more modern pan-ethnic approach has become exemplified by cystic fibrosis (CF), although considerable debate about future directions remains. CF screening brings several additional issues to the forefront, including that the largest molecular prenatal genetic screening program is based on a single gene disorder that is not necessarily severely disabling. On the other hand, several devastating disorders where screening is indeed available remain relatively inaccessible to prenatal patients in the general population. Future candidates to consider for broad-based screening programs include spinal muscular atrophy (SMA), fragile X, and inborn errors of metabolism. As prenatal screening for single gene disorders expands, issues to consider include inclusion criteria and risk versus benefit.

Recommendations from Multi-disciplinary Focus Groups on Cascade Testing and Genetic Counseling for Fragile X-associated Disorders

The purpose of this paper is to report the outcome of a collaborative project between the Fragile X Research and Treatment Center at the Medical Investigation of Neurodevelopmental Disorders (M.I.N.D.) Institute at the University of California at Davis, the National Fragile X Foundation (NFXF), and the Centers for Disease Control and Prevention (CDC). The objective of this collaboration was to develop and disseminate protocols for genetic counseling and cascade testing for the multiple disorders associated with the fragile X mental retardation 1 (FMR1) mutation. Over the last several years, there has been increasing insight into the phenotypic range associated with both the premutation and the full mutation of the FMR1 gene. To help develop recommendations related to screening for fragile X-associated disorders, four, two day advisory focus group meetings were conducted, each with a different theme. The four themes were: (1) fragile X-associated tremor/ataxia syndrome (FXTAS); (2) premature ovarian failure (POF) and reproductive endocrinology; (3) psychiatric, behavioral and psychological issues; and (4) population screening and related ethical issues.

Attitudes toward fragile X mutation carrier testing from women identified in a general population survey

Fragile X syndrome is primarily due to a CGG repeat expansion found in the FMR1 X-linked gene. In a previous study, we conducted focus groups with women to assess their attitudes towards fragile X carrier screening. In this follow-up study, we conducted in-depth interviews of general population reproductive-age women who were identified as carriers. We explored their attitudes toward testing for carrier status of the fragile X mutation. These women underwent screening primarily to participate in a research project rather than in search of a diagnosis for specific symptoms. As such, these women were wholly unprepared for positive carrier results. Their responses about their results and carrier screening, in many cases, were being worked out over the course of the interview itself. The most salient finding of this work is the apparent lack of relevance of carrier status to these women. Many expressed that although the information could be relevant in the future, it is not relevant at this stage of their lives in terms of family planning (either with respect to having unaffected offspring or to premature ovarian failure) and personal relationships. Although issues of abortion seemed prominent in the focus groups, we found that carrier status did not have an apparent effect on women's attitudes about termination. We hypothesize this may be related to the fact that women had not processed their new carrier status and had not related it to previously-formed personal opinions. The findings of this work have significant implications for genetic counseling and population screening. Genetic counselors should be mindful that general population women may not recognize the immediate importance of their carrier status even when literature is provided and discussed prior to providing a sample. As part of comprehensive genetic counseling, counselors should identify the reproductive life stage of the woman receiving the new information and help her identify when this information would be more meaningful in her life. Counselors can assist in setting up a personalized road map with specific types of services that will be more applicable to the woman as her carrier status becomes more relevant.

The FMR1 premutation and reproduction

OBJECTIVE

To update clinicians on the reproductive implications of premutations in FMR1 (fragile X mental retardation 1). Fragile X syndrome, a cause of mental retardation and autism, is due to a full mutation (>200 CGG repeats). Initially, individuals who carried the premutation (defined as more than 55 but less than 200 CGG repeats) were not considered at risk for any clinical disorders. It is now recognized that this was incorrect, specifically with respect to female reproduction.

DESIGN AND SETTING

Literature review and consensus building at two multidisciplinary scientific workshops.

CONCLUSION(S)

Convincing evidence now relates the FMR1 premutation to altered ovarian function and loss of fertility. An FMR1 mRNA gain-of-function toxicity may underlie this altered ovarian function. There are major gaps in knowledge regarding the natural history of the altered ovarian function in women who carry the FMR1 premutation, making counseling about reproductive plans a challenge. Women with premature ovarian failure are at increased risk of having an FMR1 premutation and should be informed of the availability of fragile X testing. Specialists in reproductive medicine can provide a supportive environment in which to explain the implications of FMR1 premutation testing, facilitate access to testing, and make appropriate referral to genetic counselors.