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Objective:To explore the characteristics and influencing factors of blood carnitine metabolism in premature infants.Methods:A retrospective analysis of 37 037 neonates with negative results of genetic metabolic disease screening at Guangxi Newborn Disease Screening Center from 2018 to 2021, of which 34 517 normal full-term infants were the control group and 2 520 preterm infants were the research group.According to gestational age, the preterm infants were further divided into three groups: extremely preterm group( n=232), moderately preterm group( n=324)and late preterm group( n=1 964). According to birth weight, they were divided into three groups: very low birth weight group( n=188), low birth weight group( n=1 276)and normal birth weight group( n=1 056). According to blood collection time, they were divided into three groups: 3~7 days group( n=1 990), 8~14 days group( n=342) and 15~28 days group( n=188). Tandem mass spectrometry was used to detect the levels of 31 carnitines in dried blood spots and analyze the differences in the levels of metabolic indicators in each group. Results:Carnitine levels in preterm infants are most affected by gestational age.Adjusting the physiological and pathological conditions of premature infants and other related factors, grouped by gestational age, there were differences in the levels of 31 carnitines among the groups(all P<0.05), the smaller the gestational age, the greater the difference in carnitine levels; grouped by blood collection time, there were statistically significant differences in carnitine levels between preterm infants with different blood collection age groups and full-term 3~7 days groups(all P<0.05), and showing age-related; there are differences among 31 carnitines grouped by body weight(all P<0.05), the smaller the body weight, the greater the difference in carnitine levels.Combined with the analysis of gestational age, birth weight and blood collection date, 17 indicators including C0, C2, C3, C4, C6DC, C10, C10∶1, C12, C12∶1, C14, C14∶1, C14OH, C16, C16∶1, C18, C18∶1 and C18∶1OH are important biomarkers of carnitine metabolism in premature infants. Conclusion:Carnitine in premature newborns has different metabolic differences at different gestational ages, birth weights and blood collection ages, which provides a strong basis for establishing reference standards and interpretation of preterm infants in the laboratory in this region, and provides reasonable and effective early diagnosis and treatment for clinical practice.Meanwhile, it provides an optimized program for timely detection of carnitine deficiency and carnitine supplementation to improve nutrition of premature infants.
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Objective:To study the incidence of glucose-6-phosphate dehydrogenase (G6PD) deficiency and the gene carrying status of newborns in Guangxi Zhuang Autonomous Region (Guangxi for short), so as to provide theoretical basis for clinical genetic counseling and accurate diagnosis.Methods:A total of 63 606 newborns who underwent G6PD screening in Guangxi Neonatal Disease Screening Center from January 2017 to December 2018 were selected as study subjects; heel blood was collected to prepare dry blood spots. Fluorescence quantitative analysis was used in the preliminary screening, and the newborns with positive preliminary screening were recalled by telephone; further diagnosis was carried out via the G6PD/6-phosphogluconate dehydrogenase (6PGD) ratio method and genetic testing, the diagnosis rate of the two methods of newborns with positive preliminary screening were compared and analyzed, and genetic mutation testing was conducted.Results:Among 63 606 newborns who underwent G6PD preliminary screening, 4 267 newborns with G6PD positive were detected, and the positive rate of preliminary screening was 6.7%. Among them, the positive rates of preliminary screening of males and females were 10.3% (3 508/33 988) and 2.6% (759/29 618), respectively. The positive rate of preliminary screening of males was significantly higher than that of females ( P < 0.01). A comparative analysis of 777 newborns (519 males and 258 females) that underwent G6PD/6PGD ratio method and genetic testing at the same time as the recall showed that the diagnosis rate of the two methods for male newborns was the same, both of which were 95.6% (496/519). Among female newborns, 168 and 236 confirmed cases were detected by G6PD/6PGD ratio method and genetic testing, respectively, and the diagnosis rates were 65.1% (168/258) and 91.5% (236/258), respectively. The results of genetic mutation testing showed that the five common genotypes in Guangxi were c.1388 G>A, c.1376 G>T, c.95 A>G, c.871 G>A, and c.1024 C>T, respectively. Conclusions:The positive rate of G6PD preliminary screening of newborns in Guangxi is relatively high. It is recommended that G6PD/6PGD ratio method and genetic testing should be performed at the same time for diagnosis of female newborns with positive preliminary screening to avoid missed diagnosis and misdiagnosis.
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OBJECTIVE@#To analyze the metabolic profile and genetic variants for newborns with primary carnitine deficiency (PCD) from Guangxi, China.@*METHODS@#From January 2014 to December 2019, 400 575 newborns from the jurisdiction of Guangxi Zhuang Autonomous Region Newborn Screening Center were subjected to tandem mass spectrometry (MS/MS) analysis. Newborns with positive results for PCD and their mothers were recalled for retesting. Those who were still positive were subjected to sequencing of the SLC22A5 gene.@*RESULTS@#Twenty-two newborns and 9 mothers were diagnosed with PCD, which gave a prevalence rate of 1/18 208. Sequencing of 18 newborns and 4 mothers have identified 14 types of SLC22A5 gene variants, with the common ones including c.51C>G (10/44, 22.7%), c.1195C>T (9/44, 20.5%) and c.1400C>G (7/44, 15.9%), The c.517delC(p.L173Cfs*3) and c.1031C>T(p.T344I) were unreported previously and predicted to be pathogenic (PVS1+PM2_supporting+PM3+PP4) and likely pathogenic (PM1+PM2_supporting+PM3+PP3+PP4) based on the American College of Medical Genetics and Genomics standards and guidelines.@*CONCLUSION@#c.51C>G, c.1195C>T and c.1400C>G are the most common variants underlying PCD in Guangxi.
Subject(s)
Humans , Infant, Newborn , Cardiomyopathies , Carnitine/deficiency , China , Hyperammonemia , Metabolome , Muscular Diseases , Mutation , Solute Carrier Family 22 Member 5/genetics , Tandem Mass SpectrometryABSTRACT
Objective To analyze the effects of different thyroid stimulating hormone (TSH) cut-off values on the screening of congenital hypothyroidism (CH) in newborns in Guangxi.Methods The TSH results of 83 608 newborns tested by Genetic Screening Processor (GSP) from the Genetic Metabolism Center of the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from May 2017 to April 2018 were collected.Using the percentile method and the receiver operating characteristic (ROC) curve method,the TSH cut-off values were calculated and compared with the assumed cut-off values 9.00 or 10.00 mU/L,to analyze the effects of four different TSH cut-off values on CH screening.Results Using GSP,the TSH results of 83 608 newborns showed a positive skewed distribution,TSH cut-off value of the percentile method (P99) was 7.96 mU/L,836 cases were suspicious,43 cases were diagnosed with CH (6 cases were missed diagnosis),and 65 cases were high TSH (21 cases were missed diagnosis);TSH cut-off value of the ROC curve method was 6.45 mU/L,1 480 case were suspicious,49 cases were diagnosed with CH,and 86 cases were high TSH,both were no missed diagnosis;when TSH cut-off values were 9.00 or 10.00 mU/L,the suspicious were 478 and 305 cases,respectively,and the confirmed CH were 37 and 35 cases (missed diagnosis were 12 and 14 cases,respectively),high TSH were 46 and 33 cases (missed diagnosis were 40 and 53 cases,respectively).The CH incidence of the ROC curve method was compared with the percentile method and using the cut-off values 9.00 and 10.00 mU/L,the differences were statistically significant (P ＜ 0.05).Conclusions The GSP and ROC curve method were used to successfully establish the TSH cut-off value on the screening of CH in newborns in Guangxi.The cut-off value can not only ensure the accuracy of screening,but also avoid missed diagnosis and reduce birth defects.
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Objective To investigate the characteristics of the phenylalanine hydroxylase( PAH)gene muta﹣tions in patients With phenylketonuria(PKU)in Guangxi region,in order to provide clinical data for genetic counseling and prenatal gene diagnosis. Methods Thirty－seven children diagnosed as PKU in the Maternal and Children＇s Hos﹣pital of Guangxi Zhuang Autonomous Region Were enrolled in the study betWeen January 2009 and December 2017. Ve﹣nous blood Was collected and the PAH gene sequence Was determined by Sanger sequencing after amplification With the polymerase chain reaction technique. The neW gene mutations Were defined based on the national and international literature revieW and databases. MeanWhile,100 healthy individuals Were selected as the control group for gene sequen﹣cing to confirm Whether the mutation Was a neW one. Results Thirty－seven cases of PKU Were detected for 68 muta﹣tions,With the detection rate being 91. 89%(68／74). Six mutations Were identified in exon 7,Which accounted for 31. 08% of all,exon 12(18. 92%),exon 8(10. 81%)and exon 6(10. 81%)folloWed. A total of 25 different muta﹣tions Were identified Which including 14 missense mutations(56. 00%),7 nonsense mutations(28. 00%),3 splicing junction mutations(12. 00%),and 1 deletion mutation(4. 00%). The most common mutations included c. 1223G＞A (p. R408Q),c. 728G＞A(p. R243Q)and c. 721C＞T( p. R241C),accounting for 14. 86%,13. 51%,and 10. 81%, respectively. After querying international databases,including PAH mutation database and Human Gene Mutation Data﹣base and forecasting softWare,three kinds of mutations c. 314C＞ T(p. T105I),c. 583A＞ G(p. K195E),c . 851G＞A(p. C284Y)Were verified as novel PAH gene mutations. Conclusions The mutation spectrum of the PAH gene in Guangxi has been identified. And 3 kinds of mutations have been identified. This may accumulate valuable information for gene diagnosis and prenatal diagnosis of PKU in Guangxi region.
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Objective@#To investigate the clinical, biochemical and genetic features of four carnitine-acylcarnitine translocase deficiency cases.@*Methods@#Four cases diagnosed with carnitine-acylcarnitine translocase deficiency from Guangxi Maternal and Child Health Hospital were studied. DNA was extracted from dry blood filter for gene analysis. SLC25A20 gene analysis was performed in 1 case and the whole exon sequence analysis was performed in 3 cases.@*Results@#Retrospective study on unrelated carnitine-acylcarnitine translocase deficiency patients, the age of onset was 1-28 d, the age of death were 1.5-30 d, main clinical features were hypoglycemia (4 cases), arrhythmia (2 cases), sudden death (2 cases). Biochemical test showed hypoglycemia (1.2-2.0 mmol/L) , elevated creatine kinase (955-8 361 U/L) and creatine kinase isozyme(199-360 U/L), normal or decreased free carnitine level (3.70-27.07 μmol/L) , elevated long-chain acylcarnitine (palmityl carnitine 1.85-14.84 μmol/L). The gene tests showed that all 4 cases carried SLC25A20 gene c.199-10T> G homozygous mutation, inherited from their parents. By analyzing the haplotype, we found that the mutation loci of C. 199-10T> G were all in the same haplotype.@*Conclusion@#The c.199-10T> G mutation is an important molecular cause of carnitine-acylcarnitine translocase deficiency, which has relatively high frequency in Guangxi population, and is related to the founder effect.
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Objective To use the matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) technique for detecting the mutation gene of neonatal non-syndromic hereditary hearing impairment gene in Guangxi and to investigate its effectiveness and feasibility in clinical application.Methods A total of 7 100 newborns were performed the hearing preliminary screening and secondary screening by adopting AABR.The genomic DNA was extracted by the heel blood spot.Twenty mutation characteristics of 4 deaf predisposing genes were detected by MALDI-TOF-MS.Results The pass rate of hearing screening in 7 100 newborns was 97.11％ (6 895/7 100),the positive rate of neonatal gene mutation was 3.54％ (251/7 100),in which the GJB2 gene mutation was in 131 cases,the carrying rate was 1.84％,235delC heterozygous mutation was in 108 cases.SLC26A4 gene mutation was in 93 cases,which dominated by 1229C＞T heterozygous mutation and IVS7-2A＞G heterozygous mutation,mtDNA12SRNA gene mutation was in 16 cases and GJB3 gene mutation was in 11 cases.Conclusion Adopting the MALDI-TOF-MS screening technique can increase the detection rate of hot point mutation in common deaf related genes and discover neonatal genetic NSHI from molecular level and provides the corresponding geneticconsulting guidance for early finding and predicting deaf occurrence,and formulating the interventional measures.
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Objective To analyze blood Met、 Phe 、Tyr、 Arg、 Cit、 Orn、 Ser、 Thr、 C0、 C2、 C3、 C14、C14 ∶ 1 , C16 , C16 ∶ 1 , C18 , C18 ∶ 1 and urine 4-OH-PHPLA , 4-OH-PHPPA level of NICCD patient and discuss the application value of diagnosis NICCD. Methods From May 2011 to May 2015, 21 NICCD patient were diagnose in Guangxi Newborn Screening Center. Meanwhile, 100 normal children were selected as the control group. Blood Met, Phe, Tyr and other factors and urine 4-OH-PHPLA, 4-OH-PHPPA level were analyzed by SPSS. Results In the experimental group, blood Met, Phe, Tyr and many other indexes and urine 4-OH-PHPLA, 4-OH-PHPPA level were higher and blood Orn/Cit were lower than the control group(P 0.05). Conclusion NICCD patient has abnormal biochemical index. Blood test by TMS and urine test by GC-MS are very important in NICCD diagnosis.