Objective To investigate the feasibility of DNA sequencing analysis in molecular diagnosis for spinal muscular atrophy (SMA). Methods Two pairs of primers were utilized to amplify the region including 5 different bases in SMA-causative gene SMN1 and its homologue copy SMN2 by polymerase chain reaction (PCR). The first primer amplified a fragment 501 bp long spanning from SMN intron 6 to intron 7 targeting four different bases (g.31957, 32006, 32154 and 32269). The second primer reversely amplified a 189 bp long fragment within SMN exon 8 including one base-pair differ-ence (g.32734). PCR procedure was followed by Sanger sequencing technique to identify the 5 different bases. SMA patients caused by SMN1 homozygous deletion were distinguished from carriers or normal controls by absence of SMN1 specific bas-es in sequence chromatograms. This assay was performed in 7 SMA suspected patients and their parents. The specimens were also detected by PCR- restriction fragment length polymorphism (RFLP) method. Results It was found that 6 of 7 SMA suspected patients showed only SMN2 specific bases at the 5 different base positions among the region from intron 6 to exon 8, which meant the patient displaying only SMN2-specific nucleotide a, T, g, g and A at g.31957, 32006, 32154, 32269 and 32734, while their parents (carriers) showed a/g, T/C, g/a, g/a and A/G at the same sites. SMN1 gene was deleted in the patient, and the deletion region was inferred from intron 6 to exon 8. Because carriers had both SMN1 and SMN2 genes, they can be discriminated from the SMN1 deleted patient. One of 7 patients yield an unique sequence chromatogram of a, T, g, g and A/G, indicating that exon 8 of SMN1 was not deleted in this patient. Conclusion DNA sequencing analysis is an alter-native simple method for detecting SMA caused by homozygous deletion of SMN1. We recommend to replace the widely used PCR-RFLP method with DNA sequencing assay.

Objective To explore pathogenic composition of hand,foot and mouth disease(HFMD),and the molecular typing of enterovirus in Tianjin Children′s Hospital in 2016.Methods Single center study.A total of 327 samples of HFMD cases which collected from Tianjin Children′s Hospital from March to November in 2016 were tested for nucleotide acid of enterovirus(EV),human enterovirus 71(EV71),Coxsackievirus A 16(CA16)by real-time reverse transcription polymerase chain reaction(RT-PCR),among which 104 sample of other EV positive were selected to amplify and sequence the whole VP1 region by using RT-PCR.Homology was analyzed and phylogenetic tree were constructed by comparison of the sequence with all subgenotype of EV by Chromas1.62 and MEGA6.06.EV positive rate in different age groups were compared by SPSS20.0.Results Of all the 327 HFMD cases tested,there were 272 EV positive cases,the constituent ratio of EV71,CA16 and other EV were 55.1％(150/272),6.6％(18/272)and 38.2％(104/272)respectively.The EV positive rates of different age groups(69.0％-90.9％)were different significantly(x2=15.897,P=0.044),the 3 years-old-group had the highest EV positive rate than that of the other age groups(90.9％,40/44).Of all 104 samples of other EV tested,34 were CA10(12.5％)and 14 were CA6(5.1％).Phylogenetic analysis of 11 EV71 VP1 and 20 CA10 VP1 showed that the EV71 and CA10 strains belonged to genotype C4a and genotype G,respectively.ConclusionsEV71 was still the predominant pathogen in spite of the constituent ratio of other EVs increased markedly in 2016 in Tianjin.It is important to enhance etiological monitoring for control and prevention of HFMD.

BACKGROUNDTo provide a simple, specific and early serodiagnostic technique for the patients with aseptic meningitis caused by echovirus.

METHODSAn indirect enzyme-linked immunosorbent assay (ELISA) has been developed to detect echovirus-IgM and the specificity and availability of the assay were also examined.

RESULTSIn 78 cerebrospinal fluid (CSF) specimens which came from the children with aseptic meningitis, the positive rate was 17.9(14/78). In 64 CSF collected from non-aseptic meningitis (bacterial meningitis and cerebral trauma), the positive rate was 1.56(1/64). In 5 CSF specimens which were ELISA positive, the positive rate of neutralization test (NT) was 4/5, all the specimens which were ELISA negative were NT negative. In this assay there was no cross-reaction with poliovirus, Coxsackie virus B type 1-6 and A type 7. By blocking and destructive test of specific IgM, all CSF specimens with ELISA positive became negative.

CONCLUSIONSThe established indirect ELISA was specific and reliable. The te st was quick, simple and available, which is suitable for early and specific clinical diagnosis, and will be greatly significant to clinical treatment.

Adult ; Antibodies, Viral ; cerebrospinal fluid ; Child ; Child, Preschool ; Echovirus Infections ; diagnosis ; Enzyme-Linked Immunosorbent Assay ; methods ; Humans ; Immunoglobulin M ; cerebrospinal fluid ; Infant ; Infant, Newborn ; Meningitis, Aseptic ; diagnosis ; virology

OBJECTIVETo investigate the characteristics of the phenylalanine hydroxylase (PAH) gene mutations in patients with phenylketonuria (PKU) in Tianjin and surrounding area, in order to provide basic information for genetic counseling and prenatal gene diagnosis.

METHODSAll of the 13 exons and flanking introns of the PAH gene from 99 patients with PKU were amplified by polymerase chain reaction and analyzed by single strand conformation polymorphism (SSCP), denaturing high performance liquid chromatography (DHPLC) and DNA sequencing.

RESULTSMutations were found in all exons or flanking introns of the PAH gene except for exons 9 and 13. A total of 41 different mutations were identified which corresponded to 93.94% (186/198) of the PAH alleles, including 22 missense mutations (53.6%), 7 nonsense mutations (17.1%), 9 splicing junction mutations(22.0%), and 3 deletion mutations (7.3%). Six novel mutations (IVS3nt+1g--> a, A165D, Q301X, G344D, P362L and R413G) were identified and another 6 mutations (S16fsdelCT, R71H, IVS5nt+1g--> a, G239S, R243X and R261X) were reported in Chinese population for the first time according to the databases from http://www.pahdb.mcgill.ca. The most common mutations included 243Q (36/198,18.18%), V399V (22/198, 11.1%), R111X (19/198, 9.6%), E6nt-96A--> g (18/198, 9.1%), R413P (15/198, 7.6%) and Y356X (13/198, 6.6%). In addition, 4 silent mutations (except V399V) in exons and 8 variations in introns were found in this study. The IVS1nt+40t--> g and IVS10nt-31g--> a were confirmed as novel variations by international PAH databases and IVS5nt-54g--> a was the first report in China.

CONCLUSIONThe frequencies of six common mutations were close to that in Beijing area of China, but it was different in sequence. The extensive mutation spectrum of the PAH gene showed higher heterogeneity in Tianjin and surrounding areas of Northern China comparing with other reports. According to this report, exons 7 and 11 are the hot spots and should be detected first for PAH gene quick diagnosis in this area, then comes exons 3, 6 and 12, and finally exons 5, 10 and others.

Adolescent ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; China ; Exons ; Female ; Humans ; Infant ; Infant, Newborn ; Introns ; Male ; Molecular Sequence Data ; Mutation ; Phenylalanine Hydroxylase ; genetics ; Phenylketonurias ; enzymology ; genetics ; Sequence Analysis, DNA

OBJECTIVE To detect potential mutation in a Chinese family affected with beta-ureidopropinoase deficiency. METHODS Genomic DNA was extracted from peripheral blood samples. All exons and flanking intron regions of the UPB1 gene were amplified by PCR and detected by direct sequencing. RESULTS A homozygous mutation c.977G>A was identified in exon 9 of the UPB1 gene in the proband. Both parents of the proband had heterozygous change of the same site. CONCLUSION The c.977G>A mutation of the UPB1 gene is responsible for the pathogenesis of the disease in the infant.
Abnormalities, Multiple ; genetics ; Amidohydrolases ; deficiency ; genetics ; Brain Diseases ; genetics ; Exons ; Humans ; Infant ; Male ; Movement Disorders ; genetics ; Mutation ; Purine-Pyrimidine Metabolism, Inborn Errors ; genetics

OBJECTIVETo detect potential mutation in a Chinese family affected with succinic semialdehyde dehydrogenase deficiency.

METHODSGenomic DNA was extracted from the peripheral blood samples of the proband, her family members and 100 healthy controls. All exons and flanking intronic regions of the ALDH5A1 gene were amplified by PCR and subjected to direct sequencing.

RESULTSThe proband was found to have compound heterozygous mutations of the ALDH5A1 gene, namely c.398_399delAA (p.N134X) and c.638G>T (p.R213L), for which her parents were both heterozygous carriers. The same mutations were not found among the 100 healthy controls.

CONCLUSIONThe novel mutations of the ALDH5A1 gene probably underlie the pathogenesis of the disease in the infant, which also enriched the mutation spectrum of the ALDH5A1 gene.

Amino Acid Metabolism, Inborn Errors ; ethnology ; genetics ; Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; DNA Mutational Analysis ; methods ; Developmental Disabilities ; ethnology ; genetics ; Exons ; genetics ; Family Health ; Female ; Heterozygote ; Humans ; Infant ; Introns ; genetics ; Male ; Mutation ; Sequence Homology, Amino Acid ; Succinate-Semialdehyde Dehydrogenase ; deficiency ; genetics

Objective To find out a method that is simple and reliable for screening phenylketonuria(PKU) heterzygotes.Methods Detecting and analyzing plasma phenylalanine(Phe) and tyrosine(Tyr) from 101 known-PKU heterozygotes and 2023 married people by means of a high performance liquid chromatograph.Results Significant differences were observed between known-PKU heterozygotes and screening population in plasma Phe, Phe/Tyr and Phe2/Tyr. The values of plasma Phe, Phe/Tyr and Phe2/Tyr from 94.1% known-PKU heterozygotes were higher than +2s of those values from screening population. According to the limits of +2s,81 cases were screened out from the 2023 married people. It was the first time to get the actual heterozygote frequency of 4% from population.Conculsion The biochemical method mentioned above is available for use in screening PKU heterozygotes.

OBJECTIVE: To explore the molecular etiology for a Chinese family affected with beta-ureidopropinoase deficiency. METHODS: Genomic DNA was extracted from the peripheral blood samples of family members. All exons and flanking intron regions of the UPB1 gene were amplified by PCR and detected by direct sequencing. The pathogenicity of identified mutation was analyzed using Polyphen2 and SIFT software. RESULTS: Compound heterozygous mutations of the UPB1 gene, including c.853G>A (p.A285T) and c.917-1G>A, were discovered in the proband, which were inherited respectively from his mother and father. Bioinformatics analysis suggested that this novel mutation was damaging. CONCLUSION The compound heterozygous mutations of the UPB1 gene probably underlie the beta-ureidopropinoase deficiency in the infant. Discovery of c.853G>A also enriched the mutation spectrum of the UPB1 gene.
Abnormalities, Multiple ; genetics ; Amidohydrolases ; deficiency ; genetics ; Asian Continental Ancestry Group ; Brain Diseases ; genetics ; China ; Exons ; Humans ; Infant ; Introns ; Movement Disorders ; genetics ; Mutation ; Pedigree ; Purine-Pyrimidine Metabolism, Inborn Errors ; genetics

Objective To investigate the spectrum of CYP21A2 gene mutation and the correlation between genotype and phenotype in patients with 21-hydroxylase deficiency in Tianjin and surrounding areas.Methods Genomic DNA was extracted from the peripheral blood samples of the proband.Locus-specific PCR,direct sequencing of PCR amplification products,and multiplex ligation-dependent probe amplification were applied to detect pathogenic gene CYP21A2 and the relationship between genotypes and phenotypes was analyzed.Results (1) Of 35 patients with 21-hydroxylase deficiency,25 were classified as salt-wasting phenotype and 10 were simple virilizing phenotype.(2) 69 mutant alleles were detected in a total of 70 alleles in 35 patients.Only one mutant allele was detected in one patient.Two mutant alleles were detected in all other patients,with the mutation detection rate 98.6％.(3) A total of 6 types of mutations were detected,of which c.293-13C/A＞G (I2G) was the most common,accounting for 57.1％ (40/70),followed by 18.6％ (13/70) for large gene deletion or conversion,and 14.3％ (10/70) for p.I173N.In addition,a novel mutation,c.949C＞T (p.R317X),which has not been reported previously,was detected as a pathogenic mutation.(4) Correlation analysis of genotype and phenotype in 35 children showed that the phenotype predicted by genotype was consistent with the actual salt-wasting phenotype in 31 children,and those in three children were inconsistent with the actual clinical phenotype.Conclusion The mutation characteristics of CYP21A2 gene in patients with 21-hydroxylase deficiency in Tianjin and surrounding areas are slightly different from those reported in other regions in China.A mutation c.949C＞T has not been reported,which enriches the mutation spectrum of CYP21A2 gene and provide the foundation for genetic counseling and prenatal diagnosis.

Objective:Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province.Methods:The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared.Results:A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M( P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant ( P=0.003). Conclusion:COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.