Prenatal genetic carrier testing using triple disease screening
C. M. Eng, C. Schechter, J. Robinowitz, G. Fulop, T. Burgert, B. Levy, R. Zinberg and R. J. Desnick
Department of Human Genetics, Mount Sinai School of Medicine, New York, NY 10029, USA. ceng@smtplink.mssm.edu
CONTEXT: Rapid progress in gene discovery has dramatically increased
diagnostic capabilities for carrier screening and prenatal testing for
genetic diseases. However, simultaneous prenatal carrier screening for
prevalent genetic disease has not been evaluated, and patient acceptance
and attitudes toward this testing strategy remain undefined. OBJECTIVE: To
evaluate an educational, counseling, and carrier testing program for 3
genetic disorders: Tay-Sachs disease (TSD), type 1 Gaucher disease (GD),
and cystic fibrosis (CF) that differ in detectability, severity, and
availability of therapy. DESIGN: Potential participants received education
and genetic counseling, gave informed consent, chose screening tests, and
completed pre-education and posteducation questionnaires that assessed
knowledge, attitudes toward genetic testing, and disease testing
preferences. SETTING: Medical genetics referral center. PATIENTS: Volunteer
sample of 2824 Ashkenazi Jewish individuals enrolled as couples who were
referred for TSD testing. INTERVENTION: Genetic counseling, education, and
if chosen, genetic testing for any or all 3 disorders. MAIN OUTCOME
MEASURE: Acceptance of screening for each of the 3 disorders. Secondary
outcomes include attitudes toward genetic testing and reproductive
considerations. RESULTS: Of the 2824 individuals tested for TSD, 97% and
95% also chose testing for CF and GD, respectively. The frequency of
detected carriers was 1:21 for TSD, 1 :25 for CF, and 1:18 for GD.
Twenty-one carriercoupleswere identified, counseled, and all postconception
couples opted for prenatal diagnosis. Pre-education and posteducation
questionnaires revealed that patients initially knew little about the
diseases, but acquired disease information and increased knowledge of
genetic concepts. Education and genetic counseling increased understanding
and retention of genetic concepts and disease-related information, and
minimized test-related anxiety. Although individuals sought screening for
all 3 diseases, reproductive attitudes and decisions varied directly with
disease severity and treatability. CONCLUSIONS: These findings emphasize
the importance of genetic counseling for prenatal carrier testing and may
improve understanding, acceptance, and informed decision making for
prenatal carrier screening for multiple genetic diseases.
