Phenylketonuria (PKU): Research Activities and Scientific Advances

The NICHD's PKU-related portfolio is maintained largely through the Intellectual and Developmental Disabilities Branch (IDDB). The Institute supports diverse projects, including research on pregnancy and PKU, gene therapy, improved screening, and pathophysiology of the disorder.

Institute Activities and Advances

Since its establishment, the NICHD has played a major role in PKU-related research. In the 1960s, federal Children's Bureau-supported researchers demonstrated the effectiveness of a PKU screening test that could easily and inexpensively screen for the disorder on a mass basis. Soon after, the NICHD led research on the safety and effectiveness of a restricted diet to treat PKU among newborns who had been identified using the screening test. As a result of the test and the Institute's follow-up research, PKU has been nearly eliminated as a cause of intellectual disabilities in the United States.

The NICHD continues to address newborn screening for PKU and other disorders through the Hunter Kelly Newborn Screening Research Program. The program is authorized to conduct, coordinate, and expand research in a number of screening-related areas. The topics of study include:

  • Identifying new screening methods and technologies
  • Educating the workforce of health care providers about screening
  • Developing and implementing information systems for parents and providers

  • Establishing a network of state programs for screening newborns

Other NICHD projects look at the psychosocial aspects of screening, such as how family members respond to, share, and use information gained when a newborn is diagnosed.

NICHD-supported researchers also have explored other issues central to understanding PKU and improving the lives of people who live with the disorder. One particularly significant focus has been maternal PKU. A collaborative study of women with PKU, which was initiated by the NICHD, found that women who followed a low-phenylalanine diet before and during pregnancy prevented intellectual disabilities in their offspring. The largest and most definitive clinical study of maternal PKU to date, the project also demonstrated the efficacy of dietary treatment in reducing the incidence of microcephaly, intrauterine growth retardation, and congenital heart disease among offspring.

Other Institute research focuses on aspects of PKU dietary treatments. For example, NICHD-supported researchers found that adults and adolescents on a PKU diet often had low blood levels of important fatty acids. As a result, they recommended adding supplements that provided key fatty acids as appropriate for patients.

NICHD-supported research also explores emerging treatments for PKU, such as gene therapy. For example, some researchers are studying mice to better understand the expression of the phenylalanine metabolizing system in muscles.

Other Activities and Advances

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