PREVENTION OF HOMOZYGOUS BETA-THALASSEMIA BY CARRIER SCREENING AND PRENATAL-DIAGNOSIS IN SARDINIA

Abstract

A 3 yr pilot voluntary diagnosis screening program took 2 approaches: outreach community testing and hospital testing on request after a period of sensibilization. The outreach testing was very effective as, taking into account the already known number of couples at risk with an affected proband (20), 74% of the couples at risk expected (61) on the basis of the carrier rate were identified. Less effective was the hospital testing in which half of the couples at risk expected were detected (502 with and 199 without an affected proband). After nondirective genetic counseling, approximately 85% of the couples at risk, which had a pregnancy, with no statistically significant difference between those with and those without a proband, requested prenatal testing. This figure showed a steady increase from the beginning in 1977 to 1980. All the pregnancies (42), but 2 carrying homozygous fetuses, were terminated on parental request. A continuous hospital survey of thal-major admissions in the counties showed a steady decline in the incidence figure at birth from 1976 (1213) to 1978 (1290). Even in a medium-developed, rural, Catholic population screening coupled with prenatal diagnosis can be successful in the control of a fatal, recessively inherited disorder.