title: Twenty-year outcome analysis of genetic screening programs for Tay-Sachs and beta-thalassemia disease carriers in high schools.
abstract: Programs for education, screening, and counseling of senior-high-school students, in populations at high risk for Tay-Sachs and beta-thalassemia diseases, have existed for >20 years in Montreal. Four process and outcome variables are reported here: (i) voluntary participation rates in the high-school cohort; (ii) uptake rates for the screening test; (iii) origin of carrier couples seeking the prenatal diagnosis option in the programs; and (iv) change in incidence of the two diseases. Between 1972 and 1992, we screened 14,844 Ashkenazi-Jewish students, identified 521 HexA-deficient carriers (frequency 1:28), reached 89% of the demographic cohort in the educational component of the program, and achieved 67% voluntary participation in the subsequent screening phase. The corresponding data for the beta-thalassemia program are 25,274 students (mainly of Mediterranean origin) representing 67% of the cohort with 61% voluntary participation in the screening phase (693 carriers; frequency 1:36). From demographic data, we deduce that virtually all the carriers identified in the high-school screening program remembered their status, had their partner tested if they did not already know they were a carrier couple, and took up the options for reproductive counseling/prenatal diagnosis. In Montreal, the current origin of all couples using prenatal diagnosis for Tay-Sachs and beta-thalassemia diseases is the corresponding genetic screening/testing program, whereas, at the beginning of the programs, it was always because there was a history of an affected person in the family. Incidence of the two diseases has fallen by 90%-95% over 20 years; the rare new cases are born (with two exceptions) outside the target communities or to nonscreened couples.
authors.affiliation: The DeBelle Laboratory for Biochemical Genetics and Department of Human Genetics, McGill University, Montreal, Canada.
authors.forename: J J
authors.initials: JJ
authors.lastname: Mitchell
authors.forename: A
authors.initials: A
authors.lastname: Capua
authors.forename: C
authors.initials: C
authors.lastname: Clow
authors.forename: C R
authors.initials: CR
authors.lastname: Scriver
mesh_terms: D000293:Adolescent; D005260:Female; D006580:Genetic Carrier Screening; D005817:Genetic Counseling; D005820:Genetic Testing; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D033282:Parental Consent; D011296:Prenatal Diagnosis; D011792:Quebec; D013661:Tay-Sachs Disease / Q000235:genetics*; D035141:Voluntary Programs; D017086:beta-Thalassemia / Q000235:genetics*