Research Of The Phenylalanine Determination In Neonatal Heel Blood

Objectives To design a diagnostic procedure for neonatal phenylketonuria screening to further implement of the national neonatal disease screening policy,and to standardize the process steps.Methods The data and information were collected from medical records and phone calls,neonatal heel blood samples of Tangshan were collected for experiment.The samples were to detect phenylalanine content by ninhydrin fluorescence method.PAH gene mutations screening were explored by DNA sequencing.Results The comparison between multiple samples used the χ2 test.Comparing the positive rates of different gestational ages,the difference did not have statistically significant.By comparing the false positive rates of different gestational ages,the difference had statistically significant(P<0.05).The comparison between groups was obtained by using two independent samples U test,the data showed that the false positive rate of the premature infant group and the term group was higher than that of the expired infant group.The detection value of the premature infant group had decline after two weeks(P<0.05).Gestational age factors had an impact on the accuracy of the test results.The Phe test value of central group,center edge 1/2 group and edge group were respectively 1.84±0.25 mg/d L,1.87±0.25 mg/d L and 1.67±0.22 mg/d L.According to t test analysis,the difference between the center to edge 1/2 group and the edge group was significant(P<0.05).The difference between the central group and the marginal group was also significant(P<0.05).There was no significant difference in the diagnosis rate of PKU in every season(P>0.05),but seasonal factors had effect on the accuracy of the test results between the coastal area and the mountains.There were twelve mutations detected in the PAH gene.Among these mutations detected here,R243Q(29.03%),R111X(16.13%) and R261Q(16.13%)were the main.Conclusions It is necessary to design a practical protocol of screening neonatal phenyl acetone urine for the national neonatal disease screening policy.The process specification is as follows:1 premature heel blood should be taken after the 2 w;2 speck should be expanded to 10 mm with a central location.Punch position was be suggested on the edge of the central to 1/2;3 the cold-chain transportation should be used,so as to keep the temperature and humidity constantly;4 high frequency gene should be detect for genetic testing,such as 728 G > A and 331C> T,782 G > A and 611 A > G,755 G > A and 721 C > T.Figure 11;Table24;Reference 159...