Related Experiment Video
Updated: Aug 2, 2026

Site-Directed Mutagenesis for In Vitro and In Vivo Experiments Exemplified with RNA Interactions in Escherichia Coli
Published on: February 5, 2019
Mutational and phenotypical spectrum of phenylalanine hydroxylase deficiency in Denmark
A Bayat1,2, S Yasmeen1, A Lund3
1Clinical Genetic Clinic, Kennedy Center, Copenhagen University Hospital, Glostrup, Denmark.
Abstract:
We describe the genotypes of the complete cohort, from 1967 to 2014, of phenylketonuria (PKU) patients in Denmark, in total 376 patients. A total of 752 independent alleles were investigated. Mutations were identified on 744 PKU alleles (98.9%). In total, 82 different mutations were present in the cohort. The most frequent mutation c.1315+1G>A (IVS12+1G>A) was found on 25.80% of the 744 alleles. Other very frequent mutations were c.1222C>T (p.R408W) (16.93%) and c.1241A>G (p.Y414C) (11.15%). Among the identified mutations, five mutations; c.532G>A (p.E178K), c.730C>T (p.P244S), c.925G>A (p.A309T), c.1228T>A (p.F410I), and c.1199+4A>G (IVS11+4A>G) have not been reported previously. The metabolic phenotypes of PKU are classified into four categories; 'classical PKU', 'moderate PKU', 'mild PKU' and 'mild hyperphenylalaninemia'. In this study, we assigned the phenotypic outcome of three of the five novel mutations and furthermore six not previously classified mutations to one of the four PKU categories.
Related Concept Videos
Genetic Lingo
Pedigree Analysis
Pleiotropy
Incomplete Dominance
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Inborn Errors of Metabolism

