The parents of a child diagnosed with cystic fibrosis ask the nurse what caused this disorder. What ...

ANS: B
Inborn errors of metabolism include a number of inherited diseases that affect body chemistry. There may be an absence or a deficiency of a substance necessary for cell metabolism. The deficient substance is usually an enzyme. Almost any organ of the body may be damaged. Examples of inborn errors of metabolism include cystic fibrosis and phenylketonuria (PKU). In disorders of the blood, there is a reduced or missing blood component or an inability of a component to function adequately. Sickle cell disease, thalassemia, and hemophilia fall into this category. Chromosomal abnormalities number in the thousands. Most involve some type of mental retardation, and others are incompatible with life. The newborn with Turner's syndrome or Klinefelter's syndrome may have impaired physical growth and sexual development. Malformations at birth include several types of structural defects.