Final answer:
Infants are affected by MCAD deficiency because they rely on fatty acids for energy and have limited glucose stores. MCAD deficiency impairs the body's ability to break down fatty acids, leading to hypoglycemia and potential health complications.
Step-by-step explanation:
Infants are particularly affected by MCAD deficiency because they have limited stores of glucose and rely heavily on fatty acids for energy. MCAD deficiency is a genetic disorder that impairs the body's ability to break down fatty acids for fuel. When infants with MCAD deficiency are unable to use fats as an energy source, their blood sugar levels drop rapidly, leading to a dangerous condition called hypoglycemia. This can cause seizures, organ damage, and even death if not promptly treated.