6R-tetrahydrobiopterin treated PKU patients below 4 years of age: Physical outcomes, nutrition and genotype.
Mol Genet Metab
; 115(1): 10-6, 2015 May.
Article
em En
| MEDLINE
| ID: mdl-25882749
ABSTRACT
BACKGROUND AND AIMS:
Phenylalanine-restricted diets have proven effective in treating phenylketonuria. However, such diets have occasionally been reported to hinder normal development. Our study aimed to assess whether treating 0-4-year-old phenylketonuric patients with 6R-tetrahydrobiopterin might prevent growth retardation later in life.METHODS:
We conducted a longitudinal retrospective study which examined anthropometric characteristics of phenylketonuric patients on 6R-tetrahydrobiopterin therapy (22 subjects), and compared them with a group of phenylketonuric patients on protein-restricted diets (44 subjects). Nutritional issues were also considered. We further explored possible relationships between mutations in the PAH gene, BH4 responsiveness and growth outcome.RESULTS:
No significant growth improvements were observed in either the group on 6R-tetrahydrobiopterin treatment (height Z-score initial= -0.57 ± 1.54; final=-0.52 ± 1.29; BMI Z-score initial=0.17 ± 1.05; final=0.18 ± 1.00) or the diet-only group (height Z-score initial=-0.92 ± 0.96; final= -0.78 ± 1.08; BMI Z-score initial=0.17 ± 0.97; final=-0.07 ± 1.03) over the 1-year observation period. Furthermore, we found no significant differences (p>0.05) between the two groups at any of the time points considered (0, 6 and 12 months). Patients on 6R-tetrahydrobiopterin increased their phenylalanine intake (from 49.1 [25.6-60.3] to 56.5 [39.8-68.3] mgkg(-1)day(-1)) and natural protein intake (from 1.0 [0.8-1.7] to 1.5 [1.0-1.8] g kg(-1)day(-1)), and some patients managed to adopt normal diets. Higher phenylalanine and natural protein intakes were positively correlated with better physical outcomes in the diet-only group (p<0.05). No correlation was found between patient genotype and physical outcomes, results being similar regardless of the nutritional approach used. We did not detect any side effects due to 6R-tetrahydrobiopterin administration.CONCLUSIONS:
Our study indicates that treating 0-4-year-old phenylketonuric patients with 6R-tetrahydrobiopterin is safe. However, poor developmental outcomes were observed, despite increasing the intake of natural proteins. Genotype could be a valid predictor of tetrahydrobiopterin-responsiveness, since patients who carried the same genotype responded similarly to the 6R-tetrahydrobiopterin loading test. On the other hand, harbouring 6R-tetrahydrobiopterin responsive genotypes did not predispose patients to better physical outcomes.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenilcetonúrias
/
Biopterinas
/
Estatura
/
Peso Corporal
/
Estado Nutricional
Tipo de estudo:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Child, preschool
/
Female
/
Humans
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Infant
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Male
/
Newborn
País/Região como assunto:
Europa
Idioma:
En
Revista:
Mol Genet Metab
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
/
METABOLISMO
Ano de publicação:
2015
Tipo de documento:
Article