Fragile X syndrome carrier screening in the prenatal genetic counseling setting

Abstract

Purpose: To document our experience with fragile X carrier screening. Methods: In this study, 29,103 women with no known or suspected family history of fragile X syndrome were offered fragile X carrier screening during their prenatal genetic counseling visit. Screening acceptance was analyzed by referral indication, carrier frequencies documented, and prenatal outcome data presented. Results: Overall, 7.9% accepted carrier screening. The premutation frequency was 1 in 382, and the intermediate allele frequency was 1 in 143. Conclusions: Fragile X screening is a desirable option for some women seeking prenatal genetic counseling and should be made available to this population. Genet Med 2005:7(4):246 -250.

Carrier screening in preconception consultation in primary care

“…The majority were with pregnant women (Berkenstadt et al 2007;Cronister et al 2005;Fanos et al 2006;Huang et al 2003;Pesso et al 2000;Spence et al 1996;Ryynanen et al 1999;Toledano-Alhadef et al 2001;Kallinen et al 2001), while some included relatively smaller numbers of nonpregnant women (Pesso et al 2000;Spence et al 1996;Toledano-Alhadef et al 2001;Berkenstadt et al 2007;Geva et al 2000). Most studies essentially focused on the uptake of testing, with rates varying between 7.9% ) and 21% (Spence et al 1996) in the USA, 80% in Israel (Pesso et al 2000), and 85% (Ryynanen et al 1999) and 92% respectively in two Finnish studies (Kallinen et al 2001).…”

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

“…2 Considering the severity of the syndrome, the frequency of the carrier status and the potential long-term benefits to the daughters knowing about their mother's screening result, the installment of population-based screening programs has been advocated repeatedly. [3][4][5] In addition, carrier status testing would also enable women into timely reproductive planning. 6 Even in the absence of a family history of the fragile X syndrome, the cost-effectiveness of prenatal genetic testing programs identifying the carrier status of women has been demonstrated.…”

ACMG Standards and Guidelines for fragile X testing: a revision to the disease-specific supplements to the Standards and Guidelines for Clinical Genetics Laboratories of the American College of Medical Genetics and Genomics

“…42 In the largest US study to date (of over 119,000 tested), the overall carrier frequency among US females was 1.3% (0.61% for full mutation and 1.7% for premutation). 43 A recent large-scale study of 21,411 anonymous Canadian females (mothers of newborns) identified 1 in 549 as carriers.…”