Cascade testing in families of carriers identified through newborn screening in Western Brittany (France).

ABSTRACT

BACKGROUND: Newborn screening (NBS) for cystic fibrosis (CF) can lead to the detection of healthy carriers. We report a unique assessment of family testing following the identification of carriers by NBS for over 20 years, in an area where CF is frequent. METHODS: We reviewed all of the carriers identified by NBS between 1991 and 2010 and registered the tests done in those families. RESULTS: NBS identified 0.1% of the newborns as carriers, which correspond only to 2.6% of the expected carriers born within the period, and 1/3 of those with an increased IRT level. Of the 195 families, 75.9% requested testing (2.5 tests per family). We identified 183 carriers and five 1-in-4 risk couples. Reassurance about genetic status was provided to 96% of the couples. CONCLUSIONS: Carriers detected by NBS appeared to be well managed in our area, and cascade testing that informs on genetic status seems relatively active.