Fragile X syndrome: examination of issues pertaining to population-based screening

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.

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.

Women's attitudes toward testing for fragile X carrier status: a qualitative analysis

Fragile X syndrome (FXS) is primarily due to a repeat expansion mutation found in the FMR1 X-linked gene. We have conducted a qualitative analysis of responses from women concerning their attitudes toward testing for carrier status of the fragile X mutation among reproductive-age women. We obtained responses from focus groups including women with and without FXS in their families. We found the following themes: (1) mothers of children with FXS have difficulty formulating their opinions on population screening because of their unique experiences surrounding their own carrier diagnosis and their relationship with their children with FXS, (2) the motivation for carrier testing and need for information differ by family history of FXS and parental status, and (3) the timing of carrier testing with respect to a woman's life stage dictates whether carrier information will be viewed as beneficial or detrimental. There was evidence that non-carrier women from the general population would be wholly unprepared for positive carrier results. These findings have significant implications for genetic counseling as well as for population screening.