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.

b-thalassaemia is one of the most common single-gene inherited conditions in the world, and thalassaemia carrier screening is the most widely performed genetic screening test, occurring in many different countries. b-thalassaemia carrier screening programmes provide a unique opportunity to compare the delivery of carrier screening programmes carried out in different cultural, religious and social contexts. This review compares the key characteristics of b-thalassaemia carrier screening programmes implemented in countries across the world so that the differences and similarities between the programmes can be assessed. The manner in which thalassaemia carrier screening programmes are structured among different populations varies greatly in several aspects, including whether the programmes are mandatory or voluntary, the education and counselling provided and whether screening is offered pre-pregnancy or antenatally. National and international guidelines make recommendations on the most appropriate ways in which genetic carrier screening programmes should be conducted; however, these recommendations are not followed in many programmes. We discuss the implications for the ethical and acceptable implementation of population carrier screening and identify a paucity of research into the outcomes of thalassaemia screening programmes, despite the fact that thalassaemia screening is so commonly conducted.

Most patients with intersex had positive psychosocial and psychosexual outcomes, although some problems were reported with sexual activity. These results overall suggest that a model of care including early genital surgery carried out at a centre of excellence with a multidisciplinary team can minimize long-term complication rates.

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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. Genet Med 2010:12(7):396 -410.Key Words: attitudes, carrier screening, fragile X syndrome, newborn screening, psychosocial P opulation-based screening programs for a number of genetic conditions have been established in newborn, prenatal, and preconception settings. Specific criteria, such as those developed by the World Health Organization, 1,2 are available to provide guidance on which conditions are suitable for screening. 3 Fragile X syndrome (FXS) is an X-linked genetic condition for which possible inclusion in population-based screening programs has been discussed and debated for many years. 4 -7 FXS is the most common known cause of inherited intellectual and developmental disability. It has a serious adverse impact on individuals and their families that is equivalent to that of other disabilities such as Down syndrome and autism. Most FXS cases are caused by the silencing of the FMR1 gene, which is located on the X chromosome. In these cases, the FMR1 gene is switched off as a result of an increase in the number of hypermethylated trinucleotide (CGG) repeats in the 5Ј untranslated region of the gene. Current definitions describe the normal range of CGG repeats as 6 -44, the "gray zone" range as 45-54 repeats, and the premutation range as 55-199 repeats. 8 Those affected by FXS have Ͼ200 repeats (full mutation). The length of the CGG repeat is unstable over a certain size, such that a premutation can expand to a full mutation when passed onto offspring through female, but not male, premutation carriers. 9 -11 Similarly, a gray zone allele can increase to a premutation allele when transmitted to offspring, such that a grandchild could be affected with FXS.The full mutation is associated with intell...

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Carrier screening for cystic fibrosis has been recommended for pregnant women and their partners, individuals and couples prior to conception, and for people with a family history. Many pilot programmes offering cystic fibrosis carrier screening, most commonly in the prenatal setting, have shown that uptake and acceptability are high. This article explores perspectives of the Victorian community regarding carrier screening for cystic fibrosis prior to offering screening. In particular whether or not such carrier screening should be offered, the best time for offering carrier screening, the information required for making a decision about carrier screening, and how this information can best be provided. A qualitative approach was taken to enable exploration of the views of stakeholders. Four focus groups and 32 interviews were conducted with a total of 68 participants. Participants were in agreement that cystic fibrosis carrier screening should be made available to everyone. However, potential consumers viewed cystic fibrosis carrier screening as 'not in my world' and were unlikely to request such screening unless it was offered by a health professional, or they had a family history. The best time for carrier screening was seen to be an individual preference and an information brochure was perceived to be useful when considering carrier screening. Lack of knowledge around the irrelevance of family history is a barrier to cystic fibrosis carrier screening. This study highlights the importance of community consultation, with stakeholders, prior to implementation of carrier screening programmes.