What might indicate that a newborn has inherited a genetic condition like PKU?

Failure to thrive is a critical indicator that a newborn may have inherited a genetic condition such as phenylketonuria (PKU). PKU is a metabolic disorder that results from the inability to properly break down the amino acid phenylalanine, which can accumulate to toxic levels if not managed. This can lead to a range of health issues, including developmental delays and cognitive impairment.

In newborns with PKU, the failure to thrive manifests as poor weight gain and an inability to achieve normal growth patterns. If the condition is not diagnosed and treated promptly through dietary management that restricts phenylalanine, affected infants may exhibit significant health concerns that impact their overall development. Thus, monitoring for failure to thrive can be a crucial part of early detection and intervention for genetic disorders like PKU.

While low birth weight, delayed developmental milestones, and behavioral issues can also be associated with various conditions, they are not specific indicators of PKU. Failure to thrive, specifically in the context of metabolic disorders, aligns closely with the characteristics seen in infants affected by this genetic condition.