PhD Scientific Days 2018

Budapest, April 19–20, 2018

Cognitive functions in children with Phenylketonuria

Becsei, Dóra

Dora Becsei, Semmelweis University, 1st Department of Pediatrics, Budapest

Language of the presentation


Text of the abstract


Phenylketonuria is an inherited metabolic disorder caused by the failure of the phenylalanine-hydroxilase enzyme. Untreated or poorly treated PKU can lead to intellectual disability, seizures, behavioural problems and mental disorders.


The aim of our study was to examine the cognitive functions of children with PKU comparing them with age-related control patients. The control group doesn't have any disease associated with brain damage. We examined the correlation between cognitive functions and serum Phe.


Children were examined with 5 nonverbal tests of Cambridge Cambridge Neuropsychological Test Automated Battery including tests of working memory, learning and executive function; visual, verbal and episodic memory; attention, information processing and reaction time.
Data were analyzed using Microsoft Excel, Graphpad Prism and R statistical packages. Mann-Whitney test was used to compare the two groups. Results of each task were normalized and obtained a 0-10 score system to characterize the mean cognitive functions.

Patients and results

Data of 48 children with PKU and 99 controls were collected. We got the most explicit difference in SOC subsequent thinking time: the children with PKU were 3.2 times slower. Our results show a correlation between cognitive function with age and Phe. The mean normalized cognitive function was 5,77 in the group of children with PKU, and 7,52 in the control group.


Some CANTAB tests showed significant difference between PKU and control patients - most significant one: SOC subsequent thinking time.
According to our results, the nonverbal computer tests can be used very well to examine the fine cognitive dysfunctions caused by PKU, and it has correlation with the serum Phe. These results confirm the importance of the strict diet.

Data of the presenter

Doctoral School: Clinical Medicine
Program: Prevention of Chronic Diseases in Childhood
Supervisor: Janos Bokay, Petra Zsidegh
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