The relationship between serum phenylalanine levels, genotype, and developmental assessment test results in non-phenylketonuria mild hyperphenylalaninemia patients


İlgüy M., Kılıç Yıldırım G., Eyüboğlu D., Çarman K. B., Yarar C.

EUROPEAN JOURNAL OF PEDIATRICS, cilt.184, sa.1, 2024 (SCI-Expanded, Scopus) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 184 Sayı: 1
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1007/s00431-024-05929-1
  • Dergi Adı: EUROPEAN JOURNAL OF PEDIATRICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: Ankara Developmental Screening Inventory, Denver Developmental Screening Test-II, Electroencephalogram, Non-PKU mild hyperphenylalaninemia
  • Eskişehir Osmangazi Üniversitesi Adresli: Evet

Özet

Phenylalanine (PA) levels below 360 mu mol/L do not require treatment; however, cognitive deficits have been observed in patients with elevated PA levels, necessitating a safe upper limit for treatment and therapeutic objectives. The main purpose of this study is to evaluate the correlation between developmental assessments (Denver Developmental Screening Test-II [DDST-II] and Ankara Developmental Screening Inventory [ADSI]) and electroencephalogram (EEG) findings with blood PA levels and genotypic data in non-phenylketonuria mild Hyperphenylalaninemia (HPA) patients, to re-evaluate their treatment status based on potential adverse outcomes. This study encompassed 40 patients aged 1-5 years diagnosed with HPA and not on treatment, identified through initial blood PA levels, and monitored for a minimum of 1 year on an unrestricted diet. Data on demographics, serum PA levels during presentation and follow-up, and genetic mutations were retrieved from hospital records. Patients were categorized into two groups as well-controlled (120-240 mu mol/L) and at-risk (240-360 mu mol/L) based on average PA levels. Sleep-activated EEGs and developmental assessments using the DDST-II and ADSI were conducted to compare outcomes with PA levels and genetic findings. Developmental delays in the DDST-II were observed across language, gross motor, fine motor, and personal-social domains, predominantly in males. No significant difference in delays was noted between the well-controlled and at-risk groups based on PA levels. The ADSI revealed delays in similar developmental areas, with fine motor skills being particularly prominently affected in the at-risk group. Only a well-controlled patient showed abnormal EEG results deemed unrelated to HPA. Conclusion: Our findings indicate that children with untreated PA levels above 240 mu mol/L are particularly susceptible to fine motor skill impairments, suggesting a need to reassess the PA level thresholds for initiating treatment. This study highlights the potential requirement for amending current guidelines to ensure early and appropriate intervention in non-PKU mild HPA patients, thereby mitigating the risk of developmental delays.