Study on MRI changes in phenylketonuria in patients referred to mofid hospital/iran.

[phenylketonuria]

Phenylketonuria is one of the most common metabolic disorders and the first known cause of mental retardation in pediatrics . As Screening for phenylketonuria (PKU ) is not a routine neurometabolic screening test for neonates in Iran , many PKU cases may be diagnosed after developing the clinical symptoms . One of the findings of PKU is myelination disorders , which is seen as hypersignal regions in T 2 -weighted (T 2 W ) and FLAIR sequences of brain MRI . The aim of our study was to assess MRI changes in PKU patients referred to Mofid Children 's Hospital , 2010 -2011 .We studied all PKU cases referred to our clinic as a referral neurometabolic center in Iran for brain MRI and assessed the phenylalanine level at the time of Imaging . The mean phenylalanine level (in one year ), clinical manifestations , and MRI pattern based on Thompson scoring , were evaluated .The mean age of our study group was 155 ±99 months and the mean diagnosis age was 37 ±27 .85 months . There were 15 patients with positive and 15 with negative family history . The mean phenylalanine level at the time of imaging was 9 .75 ±6 .28 and the mean 1 year phenylalanine level was 10 .28 ±4 .82 . Seventy percent of our patients had MRI involvement , in whom 20 % showed atrophic changes , in addition to white matter involvement . Based on modified Thompson scoring , the score for our study group was 4 .84 . The maximum involvement in MRI was in occipital region , followed by parietal , frontal , and temporal zones . There was not any correlation between MRI score and patients ' age . But we found significant relationship between MRI score and the age of regimen cessation . No correlation was seen between phenylalanine level (at the time of Imaging ) and MRI score . But there was a relationship between mean 1 year phenylalanine level and MRI score .According to the results of this study , brain MRI and white matter involvement can be used for evaluation of long -term control of phenylalanine level in PKU cases .