Introductory genetics courses often present recessive inheritance as
a simple "truth": if both parents carry one copy of a theoretical recessive
gene for blue eyes, each child has a 25% chance of being born with azure orbs.
If only it were that simple for cystic fibrosis.
In the 2 years since the American College of Obstetricians and Gynecologists
(ACOG) and the American College of Medical Genetics (ACMG) recommended widespread
genetic testing to determine if prospective parents carried mutations associated
with the disease, confusion over laboratory results has led some mothers to
undergo unnecessary amniocentesis. (Additional information about the ACOG
and ACMG recommendations is available at http://www.ama-assn.org/ama/pub/category/9181.html.) There have also been "unconfirmed anecdotal reports" of mothers aborting
fetuses based on bad information, said Michael Watson, PhD, at the annual
meeting of the ACMG in March.
Vastag B. Cystic Fibrosis Gene Testing a Challenge. JAMA. 2003;289(22):2923-2924. doi:10.1001/jama.289.22.2923