Evaluation of newborn hearing screening results of infants with phenylketonuria

Objective: The purpose of this study is comparing the newborn hearing screening failure rate between phenylketonuria (PKU) infants and matched healthy control infants. Patients and methods: Between April 2021 and April 2023, data obtained from the national newborn hearing screening program were examined for patients who presented to the pediatric metabolism clinic of Konya City Hospital with a clinical and genetic diagnosis of PKU. A healthy control group, matched for age and gender, was established. The newborn hearing screening test results, demographic information, and pregnancy data of infants with PKU and the control group were compared to assess risk factors. Results: In the initial screening test, 23 out of 73 PKU infants (31.5%) and 12 out of 73 infants in the control group (16.4%) failed the test (p = 0.033). Among the 23 PKU infants who did not pass the first test, 9 (35%) also failed the second test and were referred. In contrast, all 12 infants in the control group who did not pass the first test passed the second test. The failure rate in the second test was significantly higher in PKU infants compared to the control group (p = 0.003). It was observed that the maternal age of PKU infants who underwent the second test was significantly higher than that of the control group (p < 0.029). Diagnostic hearing test results were found to be normal in all nine PKU patients who failed the secondary screening test and were referred to a tertiary center. Conclusion: In our study, it was determined that infants with phenylketonuria (PKU) who did not have any risk factors for hearing loss failed the hearing screening test significantly more than healthy infants.