Introduction

Phenylketonuria (PKU) is an inborn error of metabolism characterized by pathogenic variants of the phenylalanine hydroxylase (PAH) gene with a resulting accumulation of phenylalanine (Phe) to neurotoxic levels. Diagnosis of PKU in the Latvian population began in 1985 and the present study's aim was to evaluate the available data on all PKU patients in Latvia.

Materials and methods

The medical records of 116 - DNA sample was available in 110 patients (102 nonrelated individuals) diagnosed with PKU in Latvia were obtained. Phe concentrations were measured in dried blood spots. Genomic DNA was analyzed for pathogenic variants in the PAH gene. Biochemical data were available through follow-up visits of the 83 patients.

Results

In 97% of patients (99 of 102), pathogenic variants were detected on both alleles. With an occurrence of 69.6%%, the most common pathogenic variant was the severe pathogenic variant p.Arg408Trp. The available data for 83 patients revealed that metabolic control was better in younger age groups and worse in adults.

Conclusion

Latvia exhibits a relatively homogeneous pool of disease-causing PKU alleles with a high prevalence of the classical severe form of PKU. Dietary compliance in all patients' groups is lower than expected, especially it is poor in adult age group.

中文翻译：

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拉脱维亚人群的苯丙酮尿​​症：分子基础、苯丙氨酸水平和患者依从性

介绍

苯丙酮尿症 (PKU) 是一种先天性代谢错误，其特征是苯丙氨酸羟化酶 ( PAH ) 基因的致病性变异，导致苯丙氨酸 (Phe) 积累达到神经毒性水平。拉脱维亚人群中 PKU 的诊断始于 1985 年，本研究的目的是评估拉脱维亚所有 PKU 患者的可用数据。

材料和方法

获得了拉脱维亚诊断为 PKU 的 110 名患者（102 名无关个体）的 116 - DNA 样本的医疗记录。在干血斑中测量 Phe 浓度。分析基因组 DNA 中PAH基因的致病变异。生化数据可通过对 83 名患者的随访获得。

结果

在 97% 的患者（102 名中的 99 名）中，在两个等位基因上都检测到了致病变异。发生率为 69.6%%，最常见的致病性变异是严重的致病性变异 p.Arg408Trp。83 名患者的可用数据显示，年轻组的代谢控制更好，而成年人的代谢控制更差。

结论

拉脱维亚表现出相对同质的致病 PKU 等位基因库，其中经典的严重形式的 PKU 患病率很高。所有患者组的饮食依从性均低于预期，尤其是成人年龄组更差。