Background

Accumulation of phenylalanine (Phe) due to deficiency in the enzyme phenylalanine hydroxylase (PAH), responsible for the conversion of Phe into tyrosine leads to Phenylketonuria (PKU), a rare autosomal recessive inborn error of metabolism with a mean prevalence of approximately 1:10,000 to 1:15,000 newborns. Physical, neurocognitive and psychiatric symptoms include neurodevelopmental disorder as intellectual disability and autism spectrum disorder. The most common treatments such as low-Phe diet and supplements may decrease blood Phe concentrations, but neuropsychological, behavioral and social issues still occur in some patients. This study aimed to better understand (i) the Brazilian population's knowledge about newborn screening (NBS), the main diagnostic method for PKU, as well as (ii) the impacts of phenylketonuria in the daily lives of patients and parents.

Methods

Two surveys in Real World Data format gathering of Brazilian residents by online questionnaires with (i) 1000 parents of children up to 5 years old between March and April 2019; (ii) 228 PKU patients and caregivers in March 2019. The survey was conducted in partnership with Abril Publisher and two Brazilian patient associations: Metabolic Mothers and SAFE Brasil, for families with rare diseases and PKU patients, respectively.

Results

The first questionnaire shows that 93% of parents recognize the importance of NBS and 92% report that their children have undergone the test. Still, two out of ten participants did not know what the exam is or what it is for. From the second questionnaire nine out of ten patients had their PKU diagnosis by NBS. Although strict dietary controls for PKU were claimed by 44% of respondents from second questionnaire, 55% assume not following all nutritionist recommendations and 52% did not maintain routinely Phe control levels. In addition, 53% said they had high spending on medical appointments, therapies and purchase of special foods.

Conclusions

Despite the lack of understanding, the awareness of NBS importance is present in the studied population. The early diagnosis of most PKU patients in the study corroborates with neonatal screening central role of PKU early detection. The difficulty in adhering to dietary adjustments and the possibility that current and new therapeutic strategies other than diet could be determinant to achieve the recommended Phe levels.

中文翻译：

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PKU 未满足的需求以及疾病对巴西日常生活的影响：对 228 名患者及其护理人员进行的调查结果。

背景

由于负责将 Phe 转化为酪氨酸的苯丙氨酸羟化酶 (PAH) 缺乏，导致苯丙氨酸 (Phe) 积累，导致苯丙酮尿症 (PKU)，这是一种罕见的常染色体隐性先天性代谢错误，平均患病率约为 1:10,000至 1:15,000 新生儿。身体、神经认知和精神症状包括神经发育障碍，如智力障碍和自闭症谱系障碍。最常见的治疗方法（例如低 Phe 饮食和补充剂）可能会降低血液 Phe 浓度，但一些患者仍然会出现神经心理、行为和社会问题。本研究旨在更好地了解（i）巴西民众对新生儿筛查（NBS）（PKU 的主要诊断方法）的了解，以及（ii）苯丙酮尿症对患者和家长日常生活的影响。

方法

两项以真实世界数据格式通过在线问卷收集巴西居民的调查：(i) 2019 年 3 月至 4 月期间，1000 名 5 岁以下儿童的家长；(ii) 2019 年 3 月，对 228 名 PKU 患者和护理人员进行了调查。该调查是与 Abril Publisher 和两个巴西患者协会（Metabolic Mothers 和 SAFE Brasil）合作开展的，分别针对罕见病家庭和 PKU 患者。

结果

第一份调查问卷显示，93%的家长认识到NBS的重要性，92%的家长表示他们的孩子已经接受了该测试。尽管如此，十分之二的参与者不知道考试是什么或它的目的是什么。从第二份问卷中，十分之九的患者得到了 NBS 的 PKU 诊断。尽管在第二份调查问卷中，44% 的受访者声称严格控制 PKU 饮食，但 55% 的受访者认为没有遵循所有营养师的建议，52% 的受访者没有维持常规的 Phe 控制水平。此外，53%的人表示他们在医疗预约、治疗和购买特殊食品方面的支出很高。

结论

尽管缺乏了解，但研究人群仍意识到 NBS 的重要性。研究中大多数 PKU 患者的早期诊断证实了新生儿筛查 PKU 早期检测的核心作用。坚持饮食调整的困难以及饮食以外的当前和新的治疗策略可能是达到推荐的 Phe 水平的决定因素。