Scripties UMCG - Rijksuniversiteit Groningen
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Social cognition, mental health, and quality of life and the relation to metabolic control in NTBC treated Tyrosinemia type 1 patients

(2017) Vliet, K. van (Kimber)

Tyrosinemia type 1 (HT1) is a very rare inborn error of metabolism, caused by a deficiency of the enzyme fumarylacetoacetate hydrolase in the tyrosine degradation pathway. Because of this deficiency, toxic products will accumulate, especially causing liver failure and/or liver cancer. Treatment consists of 2-(2-nitro-trifluoromethylbenoyl)-1,3-cyclohexanedione (NTBC) and a phenylalanine and tyrosine restricted diet, which diminishes these problems. Recently, however, neurocognitive deficits are reported in NTBC-dietary treated patients. This study investigated whether the problems extended to social cognition, mental health and quality of life (QoL), and the possible correlation with phenylalanine and tyrosine concentrations. 24 HT1 patients and 23 age and gender matched controls were included in this study. All participants performed the Amsterdam Neuropsychological Tasks and filled out questionnaires regarding mental health and QoL, and for each patient phenylalanine and tyrosine concentrations were collected. Results showed that HT1 patients make more mistakes on the social cognition tasks, and reported mental health problems and a lower QoL. Furthermore, several correlations were observed between social cognition scales, mental health and behavioral problems, and QoL problems. To investigate a possible cause for the neurocognitive deficits, we assessed associations between different measures of metabolic control and the previously investigated neurocognitive outcomes. Results showed correlations with both percentages of low phenylalanine and high tyrosine concentrations in the first year and throughout life. These results implicate that metabolic control, mainly in the first year of life, might contribute to the neurocognitive impairments as seen in HT1 patients.

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