Unmet needs in phenylketonuria: an exploratory Italian survey among patients and caregivers.

ABSTRACT

OBJECTIVE: Patients with phenylketonuria (PKU) require a strict diet to maintain phenylalanine (Phe) levels within the desired range. However, the diet can be onerous, resulting in poor adherence. We carried out the first online national survey in Italy to better understand the perceptions, knowledge, and experiences of both patients with PKU and caregivers with the goal of improving patient outcomes. METHODS: An online survey of 35 questions to patients and 36 questions to caregivers was distributed in September 2022 through physicians and relevant Italian associations. The information collected included knowledge and impact of PKU, unmet needs, knowledge of available drugs, and satisfaction with therapy. RESULTS: Overall, 241 questionnaires were completed by 85 patients and 156 caregivers (96.0% were parents). Knowledge of the pathogenic basis of PKU was generally high. The most common patient-reported symptoms were agitation/anxiety (48.8%), fatigue (41.1%), mood disorders (39.8%), and difficulty concentrating (33.4%). Different perspectives on adherence to a low-Phe diet were observed (22.9% of patients reported strict adherence vs. 47.0% of caregivers). Drugs that allow more freedom were needed by 49.4% of patients and 61.7% of caregivers, along with a wider range of choices of non-dietary treatments (48.2% and 60.0%, respectively). Unmet informational needs of patients included PKU and pregnancy, complications, travel, sports, and transition into adult care. CONCLUSIONS: Our data showed that patients with PKU and their caregivers reported difficulties in adherence to diet therapy and indicated interest in new therapeutic approaches. Apparent differences between patient and caregiver perspectives were identified. More informational resources on PKU are needed.

Some people are born with an abnormality in a gene called phenylalanine (Phe) hydroxylase, which controls the production of an enzyme that helps convert Phe (an important amino acid that forms proteins) to tyrosine. When Phe cannot be converted to tyrosine, it builds up in the body and becomes toxic. Phenylketone bodies then form and accumulate in the blood, resulting in a disease called phenylketonuria (PKU), which can lead to intellectual disability and epilepsy. People with PKU should follow a strict low-Phe diet so that Phe levels can remain low. However, following this diet is often difficult, resulting in poor control of PKU. We carried out the first online survey in Italy to better understand the perceptions, knowledge, and experiences of patients with PKU and their caregivers. The questionnaire was distributed in Italy in September 2022. The information collected included knowledge and impact of PKU, unmet needs of patients, knowledge of available drugs, and satisfaction with therapy. Overall, 241 questionnaires were completed by 85 patients and 156 caregivers (most were parents). Knowledge of the serious consequences of PKU was generally high. The most common symptoms were agitation/anxiety (48.8%), fatigue (41.1%), mood disorders (39.8%), and difficulty concentrating (33.4%). Our data showed that patients and caregivers reported difficulties in following the strict low-Phe diet and showed interest in treatments that allowed more freedom. There were notable differences between some patient and caregiver perspectives. More informational resources on PKU and pregnancy, complications, travel, sports, and transition from child to adult care are needed.