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

BackgroundNewborn 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.MethodsWe reviewed all of the carriers identified by NBS between 1991 and 2010 and registered the tests done in those families.ResultsNBS 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.ConclusionsCarriers detected by NBS appeared to be well managed in our area, and cascade testing that informs on genetic status seems relatively active.