Final answer:
The U.S. and Canada screen for PKU through Routine Newborn Screening, critical for early dietary management to mitigate severe symptoms. Genetic counseling can guide expectant parents on prenatal testing for genetic disorders.
Step-by-step explanation:
The correct answer to how the United States and Canada screen for those with Phenylketonuria (PKU) is B) Routine Newborn Screening. PKU is a genetic disorder where individuals lack the enzyme needed to process phenylalanine, which leads to toxic levels in the body if not managed with a strict diet. Newborn screening is essential since early intervention with a modified diet can significantly reduce the severity of symptoms associated with PKU. In the context of genetic testing and prenatal care, procedures like amniocentesis and chorionic villus sampling allow for the detection of genetic disorders before birth, and genetic counselors play a critical role in guiding expectant parents through these processes.