Mr. and Mrs. B have four children. All were seemingly healthy pregnancies, without complications. When the last child was tested for PKU shortly after birth (as required by law), the results indicated toxic levels of phenylalanine breakdown products in the blood.
- Define PKU and list several clinical manifestations.
- Describe the screening test(s) for PKU.
- Explain how dietary changes can affect the expression of PKU.
- Discuss the cause of the disease and the probable percentages of inheritance of the disease in children the couple might have in the future.