{"id":7078,"date":"2025-06-12T08:58:38","date_gmt":"2025-06-12T08:58:38","guid":{"rendered":"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/?page_id=7078"},"modified":"2026-04-15T10:42:01","modified_gmt":"2026-04-15T10:42:01","slug":"pku-management","status":"publish","type":"page","link":"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/pku-management\/","title":{"rendered":"Challenges in PKU"},"content":{"rendered":"<div id=\"acf-block-684a96bee4df2\" class=\"wrapper hero-wrapper\">\n    <div class=\"hero hero-no-overlay\">\n                    <div class=\"hero-background-image hero-background-image-desktop\" style=\"background-image: url(https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2025\/06\/challenges-in-PKU.png?v=0.136);\"><\/div>\n            <div class=\"hero-background-image hero-background-image-mobile\" style=\"background-image: url(https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/HF1309633_Palynziq_Traveling_Hero_4C_FIN_w_bkgrnd_MOBILE-Resize-2-e1774282557121-492x800.png);\"><\/div>\n                <div class=\"overlay\"><\/div>\n        <div class=\"wrapper\">\n            <div class=\"inner-wrapper\">\n                <div class=\"hero-content\">\n                    \n                                                                                    <h1>BH4 THERAPIES AND<br \/>\nRESTRICTED DIETS<br \/>\n<span class=\"green\">MAY NOT BE THE RIGHT CHOICE FOR MANY PEOPLE WITH PKU<sup>1-4<\/sup><\/span>\n<\/h1>\n                                                                                                <\/div>\n            <\/div>\n        <\/div>\n    <\/div>\n    <\/div>\n\n\n<div id=\"acf-block-69a6ed6c388a1\" class=\"block bg-band pal-tabbed-block\">\n    <div class=\"wrapper\">\n        <div class=\"inner-wrapper\">\n            <div class=\"tabbed-box\">\n                <div class=\"block-tabs\">\n                    <div class=\"tabs-slider\">\n                        <div class=\"tab active\" data-tab=\"tab-one-content\">\n                            <p>Restricted diets are challenging<sup>1,2<\/sup>\n<\/p>\n                        <\/div>\n                        <div class=\"tab\" data-tab=\"tab-two-content\">\n                            <p>BH4 therapies are not always an option<sup>3,4<\/sup>\n<\/p>\n                        <\/div>\n                    <\/div>\n                <\/div>\n\n                <div class=\"tab-content\">\n                                                                                                        <div class=\"content tab-one-content active\">\n                                                                                                            <h2 class=\"ribboned\">PKU management that requires a restricted diet is often ineffective<sup>1,2<\/sup>\n<\/h2>\n                                                                                                                                                \n                                                                                                                        \n                                                                                                                            \n                                        <figure>\n                                            <div class=\"image image-responsive\">\n                                                                                                    <div class=\"image-desktop\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/88-green.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                    <div class=\"image-mobile\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/Group-1518.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                                                            <\/div>\n                                        <\/figure>\n\n                                                                                                                                                <h2 class=\"ribboned\">Dietary adherence becomes especially challenging as children reach adolescence and face:\n<\/h2>\n                                                                                                                                                \n                                                                                                                        \n                                                                                                                            \n                                        <figure>\n                                            <div class=\"image image-responsive\">\n                                                                                                    <div class=\"image-desktop\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/50-80.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                    <div class=\"image-mobile\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/Group-1519.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                                                            <\/div>\n                                        <\/figure>\n\n                                                                                                                                                <h2 class=\"ribboned\">When dietary adherence is lost early, it can be hard to regain later<sup>10,11<\/sup>\n<\/h2>\n                                                                                                                                                \n                                                                                                                        \n                                                                                                                            \n                                        <figure>\n                                            <div class=\"image image-responsive\">\n                                                                                                    <div class=\"image-desktop\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/Group-15162.png?v=0.136\" alt=\"When dietary adherence is lost it&#039;s hard to regain\" \/>                                                    <\/div>\n                                                    <div class=\"image-mobile\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/compliance-mob.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                                                            <\/div>\n                                        <\/figure>\n\n                                                                                                                                                <div class=\"boxed\">\n                                            <h3>PKU management decisions made during adolescence <span class=\"alt\">can set the tone for long-term Phe control.<sup>6,10,14<\/sup><\/span><\/h3>\n                                        <\/div>\n                                                                                                    <\/div>\n                                                        \n                                                            <div class=\"content tab-two-content\">\n                                                                                                            <h2 class=\"ribboned\">BH4 therapies are not an option for some people with classical PKU<sup>3,4<\/sup>\n<\/h2>\n                                                                                                                                                \n                                                                                                                        \n                                                                                                                            \n                                        <figure>\n                                            <div class=\"image image-responsive\">\n                                                                                                    <div class=\"image-desktop\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/Group-1545.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                    <div class=\"image-mobile\">\n                                                        <img decoding=\"async\" class=\"\" src=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/wp-content\/uploads\/sites\/3\/2026\/03\/Group-1546.png?v=0.136\" alt=\"\" \/>                                                    <\/div>\n                                                                                            <\/div>\n                                        <\/figure>\n\n                                                                                                                                                <ul>\n<li><strong>BH4 therapies rely on some PAH activity,<\/strong> which is minimal or absent in people with classical PKU<sup>4,15<\/sup><\/li>\n<li><strong>The requirement of a long-term restricted diet<\/strong> will continue to present challenges<sup>4<\/sup><\/li>\n<\/ul>\n                                                                                                    <\/div>\n                                                                                        <\/div>\n            <\/div>\n\n                        <div class=\"bottom-text\">\n                                    <h3>Patients need flexibility to meet their PKU treatment goals.<\/h3>\n                \n                                    <a href=\"https:\/\/hcp.biomarin.com\/en-us\/palynziq\/trial-results-design\/\" class=\"button button-arrow\" target=\"\">Explore PALYNZIQ trials<\/a>\n                            <\/div>\n                    <\/div>\n    <\/div>\n<\/div>\n\n<div id=\"acf-block-684a9a3152291\" class=\"block wrapped-content bg-band bg-band-gradient block-zero-top block-zero-bottom block-remove-top-padding\">\n    <div class=\"wrapper\">\n        <div class=\"inner-wrapper\">\n                \n<div id=\"acf-block-684a9a31522c3\" class=\"block-wysiwyg references\">\n            <p>&nbsp;<\/p>\n<p><small>BH4, tetrahydrobiopterin; PAH, phenylalanine hydroxylase enzyme.<\/small><\/p>\n<p><small><br \/>\n<strong>References:<\/strong> <strong>1.<\/strong> Enns GM, Koch R, Brumm V, Blakely E, Suter R, Jurecki E. Suboptimal outcomes in patients with PKU treated early with diet alone: revisiting the evidence. <em>Mol Genet Metab<\/em>. 2010;101(2-3):99-109. doi:10.1016\/j.ymgme.2010.05.017 <strong>2.<\/strong> Ashe K, Kelso W, Farrand S, et al. Psychiatric and cognitive aspects of phenylketonuria: the limitations of diet and promise of new treatments. <em>Front Psychiatry<\/em>. 2019;10:561. doi:10.3389\/fpsyt.2019.00561 <strong>3.<\/strong> Rocha JC, Ahring KK, Bausell H, et al. Expert consensus on the long-term effectiveness of medical nutrition therapy and its impact on the outcomes of adults with phenylketonuria. <em>Nutrients<\/em>. 2023;15(18):3940. doi:10.3390\/nu15183940 <strong>4.<\/strong> Sp\u00e9cola N, Chiesa A. Alternative therapies for PKU. <em>J Inborn Errors Metab Screening<\/em>. 2017;5:1-5. doi:10.1177\/2326409816685734 <strong>5.<\/strong> Smith WE, Berry SA, Bloom K, et al. Phenylalanine hydroxylase deficiency diagnosis and management: a 2023 evidence-based clinical guideline of the American College of Medical Genetics and Genomics (ACMG). <em>Genet Med<\/em>. 2025;27(1):101289. doi:10.1016\/j.gim.2024.101289 <strong>6.<\/strong> Burton BK, Hermida \u00c1, B\u00e9langer-Quintana A, et al. Management of early treated adolescents and young adults with phenylketonuria: development of international consensus recommendations using a modified delphi approach. <em>Mol Genet Metab<\/em>. 2022;137(1-2):114-126. doi:10.1016\/j.ymgme.2022.07.012 <strong>7.<\/strong> Remor E, Gabe KM, Teruya KI, Schwartz IVD. What is known about patients\u2019 quality of life with phenylketonuria and their caregivers? A scoping review. <em>Orphanet J Rare Dis<\/em>. 2024;19(1):402. doi:10.1186\/s13023-024-03422-4 <strong>8.<\/strong> Cazzorla C, Gaiga G, Medici S, et al. Transitioning into adulthood with PKU: the role of diet, coping strategies, and quality of life in adolescents and young adults. <em>Psychol Int<\/em>. 2025;7(2):45. doi:10.3390\/psycholint7020045 <strong>9. <\/strong>Pinto A, Daly A, Evans S, Ashmore C, MacDonald A. Navigating adolescence with PKU: adherence, metabolic control, and wellbeing in a UK clinical centre. <em>Nutrients.<\/em> 2025;17(21):3409. doi:10.3390\/nu17213409<\/small><small>\u00a0<strong>10.<\/strong> Beghini M, Pichler M, Tinnefeld FC, et al. Poor adherence during adolescence is a risk factor for becoming lost to follow-up in patients with phenylketonuria. <em>Mol Genet Metab Rep<\/em>. 2024;39:101087. doi:10.1016\/j.ymgmr.2024.101087 <strong>11.<\/strong> Ford S, O\u2019Driscoll M, MacDonald A. Living with phenylketonuria: lessons from the PKU community. <em>Mol Genet Metab Rep<\/em>. 2018;17:57-63. doi:10.1016\/j.ymgmr.2018.10.002 <strong>12.<\/strong> Cazzorla C, Bensi G, Biasucci G. Living with phenylketonuria in adulthood: the PKU ATTITUDE study. <em>Mol Genet Metab Rep<\/em>. 2018;16:39-45. doi:10.1016\/j.ymgmr.2018.06.007 <strong>13.<\/strong> Anton-Paduraru DT, Trofin F, Chis A. Current insights into nutritional management of phenylketonuria: an update for children and adolescents. <em>Children<\/em>. 2025;12(2):199. doi:10.3390\/children12020199 <strong>14.<\/strong> Romani C, Manti F, Nardecchia F, et al. Adult cognitive outcomes in phenylketonuria: explaining causes of variability beyond average Phe levels. <em>Orphanet J<\/em> <em>Rare Dis<\/em>. 2019;14(1):273. doi:10.1186\/s13023-019-1225-z <strong>15.<\/strong> Blau N, Hennermann JB, Langenbeck U, Lichter-Konecki U. Diagnosis, classification, and genetics of phenylketonuria and tetrahydrobiopterin (BH4) deficiencies. <em>Mol Genet Metab<\/em>. 2011;104(suppl):S2-S9. doi:10.1016\/j.ymgme.2011.08.017<\/small><\/p>\n    <\/div>\n        <\/div>\n    <\/div>\n        <\/div>","protected":false},"excerpt":{"rendered":"","protected":false},"author":5,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"class_list":["post-7078","page","type-page","status-publish","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>PKU Treatment Challenges | Diet &amp; BH4 Limitations<\/title>\n<meta name=\"description\" content=\"Understand the challenges of a restricted diet and limitations of BH4 therapies in classical PKU.\" \/>\n<meta name=\"robots\" content=\"index, follow, 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