Evidence map›Paper›PMID 41723557›Full record

ArticleHuman genomics2026

Genotype-phenotype correlations in phenylketonuria: PAH variants and BH4 responsiveness for treatment design.

Meryem Karaca, Asuman Gedikbasi, Arzu Selamioğlu, Alihan Yesil, Guven Toksoy, Cagri Gulec, Mehmet Cihan Balci, Dilek Güneş, Behiye Tuğçe Yıldırım, Gizem Kına and 6 more

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Article in Human genomics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

16 authors.

Meryem KaracaDivision of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Turgut Özal Millet street Fatih, 34093, Istanbul, Türkiye. meryem.karaca@istanbul.edu.tr.
Asuman GedikbasiDepartment of Pediatric Basic Sciences, Institute of Child Health, Istanbul University, Fatih, 34452, Istanbul, Türkiye.
Arzu SelamioğluDepartment of Rare Diseases, Institute of Graduate Studies in Health Sciences, Istanbul University, Istanbul, Türkiye.
Alihan YesilDivision of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Turgut Özal Millet street Fatih, 34093, Istanbul, Türkiye.
Guven ToksoyDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Cagri GulecDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Mehmet Cihan BalciDivision of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Turgut Özal Millet street Fatih, 34093, Istanbul, Türkiye.
Dilek GüneşDivision of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Turgut Özal Millet street Fatih, 34093, Istanbul, Türkiye.
Behiye Tuğçe YıldırımDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Gizem KınaDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Volkan KaramanDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Ayca Dilruba AslangerDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Birsen KaramanDepartment of Pediatric Basic Sciences, Institute of Child Health, Istanbul University, Fatih, 34452, Istanbul, Türkiye.
Mubeccel DemirkolDivision of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Turgut Özal Millet street Fatih, 34093, Istanbul, Türkiye.
Zehra Oya UygunerDepartment of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Gulden Fatma GokcayDivision of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Turgut Özal Millet street Fatih, 34093, Istanbul, Türkiye.

Funding

Scientific Research Projects Coordination Unit of Istanbul University TSA-2021-37976
6 · The paper itself

Abstract

backgroundPhenylketonuria (PKU) is an autosomal recessive disorder caused by PAH alterations, leading to elevated phenylalanine (Phe) and neurotoxicity. Newborn screening (NBS) and early therapy improve outcomes. This study aimed to characterize the molecular and phenotypic spectrum of PKU, explore genotype–phenotype correlations, and evaluate the relationship between PAH variants and BH4 responsiveness to guide personalized treatment.

methodsMedical and genetic records of 171 patients diagnosed with hyperphenylalaninemia via NBS were reviewed. Demographic data, diagnostic Phe and tyrosine (Tyr) levels, BH4 loading test results, and genetic analyses including Sanger sequencing, MLPA, and array CGH were assessed. Allelic and genotype–phenotype values were used to estimate variant severity.

results168 carried ≥ 1 PAH variant; three had BH4 metabolism disorders. A total of 63 distinct PAH variants were identified; MLPA detected large deletions in three patients. Five variants (c.1066-11G > A, c.782G > A, c.143T > C, c.898G > T, c.1208 C > T) accounted for > 50% of the cohort. Among 100 patients tested, 41% responded to BH4, with c.782G > A most common (21%). Overall, 68.5% received dietary and/or BH4 therapy.

conclusionThis study contributes to our understanding of PKU’s molecular and phenotypic landscape, highlighting the importance of utilising both genotype and response to the BH4 loading test in the design of personalised treatments, beyond the initial Phe level.

Indexed as

BiopterinsGenetic Association StudiesPhenylalanine HydroxylasePhenylketonuriasChildChild, PreschoolFemaleGenotypeHumansInfantInfant, NewbornMaleMutationNeonatal ScreeningPhenotypePhenylalanineBiopterinsPhenylalaninePhenylalanine HydroxylasesapropterinBH4 loading testBH4 treatmentMLPANewborn screeningPAH genePhenylketonuria

Identifiers

PMID41723557
PMCPMC13081264

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.