Question

Patient Gender: Patient Age: Main Symptoms: Parental Genetic Mismatch Leading to Child’s Phenylketonuria Onset Time: Laboratory Test Results:

Answer

Phenylketonuria is not an issue of genetic compatibility but a congenital metabolic disorder. It is caused by chromosomal gene mutations that lead to a deficiency in the liver’s phenylalanine hydroxylase, thereby causing phenylalanine metabolism impairment and damaging the central nervous system. Phenylketonuria is one of the earliest treatable genetic metabolic diseases. Early diagnosis and prompt treatment can prevent intellectual impairment in children, allowing them to lead normal lives. The low-phenylalanine diet therapy is the only method for treating classic phenylketonuria, with the aim of preventing brain damage. The basic principle of dietary therapy is to ensure that the intake of phenylalanine meets the minimum requirements for growth and metabolism. Due to the lack of phenylalanine hydroxylase in the patient’s liver, phenylalanine accumulates in large quantities in the blood, causing the child’s urine to have a mouse-like smell. Phenylalanine is an essential amino acid, and insufficient intake can lead to growth and development delays, and in severe cases, even be life-threatening. Therefore, the intake of phenylalanine should neither be excessive nor insufficient. Since natural proteins contain 4-6% of phenylalanine, it is necessary to control the intake of natural proteins and use low or non-phenylalanine formula milk and proteins as the main sources of protein for children. In total protein intake, 80%