Screening And Diagnosis Model For Neonatal Inherited Metabolic Disease And Jene Analysis

Part 1 Screening and Diagnosis Model for Neonatal Inherited metabolic disease by tandemmassObjective:Neonatal screening is widely accepted as one of the tertiary prevention measures in the prevention of birth defects with the most value. At present, there are only 2 to 4 kinds of newborn screening for inherited metabolic diseases in China. And the number of inherited metabolic diseases which result in disability is increasing day by day. In the current system, we could establish a variety of screening methods and cutoff of amino fatty acids and acids’ metabolic diseases by the use of the most advanced tandem mass spectrometry, expand screening diseases to dozens, and definite diagnosis processes we also explore treatments of these diseases. Through epidemiological and genetic analysis, we study the disease incidence, clinical characteristics and intervention means of inherited metabolic in this region. To complete screening network and set up informational management, to analyze the profound significance of this work from the perspective of health economics. Comparing whether there are differences in neonatal morbidity between normal and high-risk newborns would provide clinical evidences for the increasing screening diseases and standards of genetic metabolic disease diagnosis and treatment.Method:From December 2010 to December 2015, in accordance with the principle of informed consent, Jinan newborn disease screening center used the tandem mass spectrometry technology to screen newborns’ blood samples. Screening diseases include 37 kinds of amino acids, organic acids, fatty acids and metabolic diseases, as well as the calculation of single disease and positive rates of disease classification screening. We collect clinical high-risk children and suspected inherited metabolic disease children at the same period, clarify the diagnosis by mass spectrometry technology platform, calculate the incidence of diseases diagnosed, and compare with the newborn screening sample spectrum and incidence.Result:Through mass spectrometry platforms, we have screened 61,702 cases of newborn,1170 positive cases, positive rate of 1.8%, and diagnosed 40 cases of positive infants. The positive rate of diagnosis screening is 1:1542 (0.65‰), which contains 23 cases of two kinds of organic acid metabolic diseases,10 cases of three kinds of amino acid metabolic diseases,8 cases of three kinds of fatty acid metabolism diseases. The center undertakes diagnosis of tandem mass spectrometry screening in suspicious children in Shandong province and its neighboring provinces. Therefore it accepts more children of referral positive screening from many regions. Additionally, it includes the screening of clinical high-risk children. From December 2010 to December 2015, there are a total of 2948 cases that cover 145 diagnosed cases of 19 kinds of amino acids and fatty acids metabolic diseases, the positive rate of 5%. the positive rate of inherited metabolic diseases of mass spectrometry in newborn screening is 1:1500, the rate of the clinical diagnosis of high-risk children in a variety of inherited metabolic diseases is 1:15. The most diagnosed diseases are methylmalonic acid disorders, hyperphenylalaninemia, primary carnitine deficiency and 3-methyl-crotonic coenzyme A carboxylase deficiency. The most diagnosed diseases with high-risk clinical are methylmalonic academia and hyperphenylalaninemia.Conclusion:Mass spectrometry for newborns’ screening for inherited metabolic diseases can greatly extend the screening kinds of diseases. Jinan has the high incidence of genetic and metabolic diseases, thus there is a need to screen neonatal babies generally. Comparing clinical common diseases with screening positive diseases, we have confirmed that having the maximum incidence and the most harmful diseases in this local are methylmalonic academia and hyperphenylalaninemia.Part Two:The genetic analysis of screening diseasesObjective:According to the positive cases diagnosed by tandem mass spectrometry screening technology, we establish a genetic diagnosis platform. We also explore treatments of these diseases. Through epidemiological and genetic analysis, we study the disease incidence, clinical characteristics and intervention means of inherited metabolic in this region.Method:As to the positive diagnosed newborns screened by genetic metabolic diseases, by the DNA analysis of mass genetic testing, we take 4 drops of peripheral blood specimens from children with clinical diagnosis of congenital hypothyroidism, hyperphenylalaninemia, congenital adrenal hyperplasia, glucose-6 phosphate dehydrogenase deficiency, and diagnosis by 37 kinds of tandem mass spectrometry screening. We extract DNA from dried blood spots using the DNA kit and quantative with Nanodrop. Using the designing software of Sequenom’s Typer 4.0, PCR amplification test mutations and a single base primer extension primer, and on the basis of documents indexed and public gene mutations inclusion criteria of NCBI PubMed, OMIM and HGMD databases, we screen 11 common kinds of amino acid metabolism gene mutations with 451 kinds and 23 common kinds of organic acid metabolism and fatty acid oxidation metabolism gene with 491 kinds of mutations.Result:In the detection of 355 cases of children with congenital hypothyroidism, the majority have no related gene mutation, and only one child has Pax8 gene mutation c.155G/C, p.Arg52Pro, but parents of the child do not carry the mutant gene, so it’s proved to be a new generation of mutation. In the gene detection of hyperphenylalaninemia of 140 cases, gene mutation sites are detected in 132 cases, consistent with clinical diagnosis; gene mutation sites are not detected in 10 cases. After Sanger sequencing, mutation sites are detected in 7 cases, of which 5 mutation sites are new mutations that are not reported; according to the protein analysis, these new mutations are likely to cause diseases. In the gene detection of 70 cases of children with congenital adrenal hyperplasia, gene mutation sites are not detected in 10 cases, a single monoallelic mutation site is detected in 5 cases, and 1 case of child has three mutation sites derived from the father. Among these children with diseases, 6 cases are excluded from the diagnosis in the follow-up, and the rest are still being followed up. The remaining 54 cases are detected to have two mutation sites derived from the father and mother; Among 35 children with diseases in the detection of glucose-6-phosphate dehydrogenase deficiency, mutation sites are not found in 6 children, while the rest children are detected to have mutation sites and detection on their mothers is conducted to confirm whether their mothers carry the diseases. The mutation site in one case is the new mutation that has not been reported.Through the tandem mass spectrum screening, it is confirmed that the diseases of 145 children are positive, in whom mutation sites are detected. Gene detection shows the positive results and common mutation sites.Conclusion:Gene detection of inherited metabolic diseases is highly valuable to the diagnosis of diseases, and it is necessary to detect parents to ensure the pathogenicity of detected gene mutation. Diseases screening in this region has common mutation sites. The genotype and phenotype of genetic metabolic disease is closely related.