Measurement of functional independence level and falls-risk in individuals with undiagnosed phenylketonuria

The aim of the study was to determine the level of functional independence in adult patients with previously undiagnosed or untreated phenylketonuria (PKU). The study was conducted among 400 intellectually impaired adult residents of Social Welfare Homes in South-Eastern Poland born prior to the introduction of neonatal PKU screening programs. PKU was screened by filter paper test using tandem mass spectrometry methods, and confirmed by gas chromatography-mass spectrometric analysis of PKU organic acids in urine. Degree of functional independence included the assessment of activities of daily living (Barthel Index) and measures of balance and gait (Tinetti scale). Eleven individuals with previously untreated PKU were identified whereby eight presented with moderate disability and three with mild disability. Six had a high risk of falls and five had a moderate risk of falls. This study indicates that there is considerable number of undiagnosed PKU patients within the Polish population who require assessment and management in order to reduce the impact of the neurological and neuropsychiatric problems associated with the condition. Appropriate therapy for those with undiagnosed PKU should, in particular, address the risk of falls.