Objective To perform PCR site-directed mutagenesis of nine novel PAH gene mutations (Y154H, R157I, Y206C, G247R, D282G, G346R, S349A, A389G, R400K) identified in northern Chinese and construct mutant recombinant plasmids of PAH gene. Methods 1) Every mutant recombinant plasmid was constructed according to the site of the mutation localized in functional domain of PAH gene and the related clinic phenotype of patients with the gene mutation. 2) Using the wild-type PAH expression vector as a templet, the mutant recombinant plasmids were directly amplified by PCR with Platinium Taq DNA polymerase and nine pairs of primers which were designed according to the human PAH cDNA sequence and the requirement for site-directed mutagenesis technology. 3) The positive strains were selected by Amp resistant test, PCR and restriction endonuclease analysis. The Mva Ⅰ, Mva Ⅰ, Hind Ⅲ, Rsa Ⅰ, Rsa Ⅰ sites exist in the sequences near the mutant sites of S349A, D282G, G247R, Y206C, Y154H, respectively, but not in the related sequence of wild-type PAH expression vector. Restriction endonuclease digestion could be directly used in identifying the mutant sites. However, the amplification created restriction site (ACRS) analysis was supplied in the followed identification of R157I, G346R, A389G, R400K. Finally the sequences of mutant recombinant plasmids of PAH gene were confirmed by DNA sequence analysis. Results Every sequence analysis showed that the mutant nucleic acids were introduced at the expected sites of PAH gene, suggesting that the mutant recombinant plasmids of PAH gene were constructed successfully. Conclusion PCR site-directed mutagenesis is accurate and highly efficient. The successfully mutagenized plasmids of PAH gene lay the foundation for the functional analysis of phenylalanine hydroxylase in mammalian cell system.

Objective:This study aimed to investigate the associations between single-nucleotide polymorphism (SNP) of IGF-1 and IGFBP-3 gene and risk of non-smoking female lung cancer in Chinese population. Methods:Genotyping was performed using the TaqMan method in 287 histologically confirmed non-smoking female lung cancer cases and 281 healthy controls. Results:The geno-type distributions of IGF-1 polymorphisms were significantly different between cases and controls (P<0.001). Analysis of multivariate logistic regression showed that the carriers of the CC genotype exhibited a significantly decreased risk of lung cancer in non-smoking female (adjusted OR=0.28, 95%CI:0.15-0.54). IGF-1 rs1520220 GG genotype may reduce the risk of advanced lung cancer incidence in nonsmoking female (adjusted OR=0.30, 95%CI:0.09-0.96). Log-rank test and Cox regression analyses revealed that variant geno-types of IGF-1 rs2946834 CT/TT had a significantly decreased lung cancer mortality risk compared with the homozygote CC in≥60 age group or patients with a lung tumor>3 cm. Conclusion:The IGF-1 polymorphism was associated with the risk of lung cancer and prognosis among non-smoking female. More rigorous laboratory studies of large sample population and functional studies are warrant-ed to confirm our findings.

Objective To perform mutation analysis of survival motor neuron gene 1 (SMN1 in two spinal muscular atrophy (SMA) patients and their parents to evaluate the effects of the two SMN1 gene mutations on the transcript levels of the gene and preliminarily predict their effects on the structure and function of SMN protein.Methods Mutation analysis of SMN1 gene was carried out by multiplex ligationdependent probe amplification,reverse transcript-polymerase chain reaction (RT-PCR) and cloning sequencing.Transmission of the mutations was confirmed by the mutation analysis in patients' parents.The full-length SMN1 (SMN1-fl) transcript levels of the patients carrying these subtle mutations were detected using quantitative RT-PCR.Results The two patients were diagnosed as SMA Ⅱ and SMA Ⅲ.They carried p.Val19GlyfsX21 and p.Ala2Gly SMN1 mutations in SMN1 gene,respectively.Both of the two mutations were originated from their fathers.Compared with the healthy individuals (23.5 ± 4.9),the two patients had a significant reduction in the level of SMN1-fl transcripts (t =3.322,P =0.011 (p.Ala2Gly) ;t =6.964,P =0.000 (p.Val19GlyfsX21)).However,compared with the healthy carriers (14.1 ±4.5),the patient with p.Ala2Gly mutation had no significant reduction in the level of SMN1-fl transcripts (13.9 ±3.6,t =0.058,P =0.955) ; however,the patient with p.Val19GlyfsX21 mutation had a significant reduction (4.9± 2.4,t =3.725,P =0.004).Conclusions Two SMN1 gene mutations are identified in our study.The mutation p.Val19GlyfsX21 is a novel mutation and p.Ala2Gly is firstly reported in Chinese SMA patients.p.Val19GlyfsX21 may possibly lead to decreased SMN1-fl mRNA by nonsense-mediated messenger RNA decay,however,p.Ala2Gly has no obvious effects on the amount of the SMN1-fl transcripts,indicating that its deleterious effect may be occurring at SMN protein level or the function of SMN protein.

Objective To analyze the distribution of common chromosomal karyotypes of patients with Turner syndrome (TS), and to explore the correlation between the age and height standard deviation scores (HSDS) on diagnosis.Methods Retrospective investigation was performed for the data of age and HSDS on diagnosis in 273 TS girls(≤ 18.0 years old)diagnosed by chromosomal karyotypes.The main statistical methods were analyzed with t-test and Pearson correlation test by using the SPSS 18.0 statistical software.Results (1) There were 4 kinds of common chromosomal karyotypes in the TS :45, X (87/273 cases,31.9％),46, X, i (Xq) (43/273 cases, 15.7％) ,45, X/46, X, i (Xq) (36/273 cases, 13.2％) and 45, X/46, XX (23/273 cases, 8.4％), respectively, the adolescent TS all had delayed puberty.For the cases with 45, X karyotypes ,3 cases presented mental retardation and 2 cases with organs deformity.(2)The patients with 45 ,X/46,X,i(Xq) karyotypes or with 46,X,i(Xq) karyotypes had the maximum(12.56 age) or the minimum(9.70 age) mean age on diagnosis, respectively, there was a significant difference between 2 groups (t =3.019, P =0.004).The maximum deviation from normal height was found in the patients with karyotypes of 46, X,i (Xq) (HSDS =-4.04), and the minimum deviation was in the patients with karyotypes of 45,X/46, XX (HSDS =-3.16), and there was a significant difference between 2 groups (t =-2.95, P =0.004).(3) More than 75.7％ of TS patients was diagnosed when their heights deviated above 3 SD,and their mean age on diagnosis was 12.10 age,which was 3 years later than those patients within 2 SD.(4) There was a significant negative correlation between the age and HSDS on diagnosis in the groups of common chromosomal karyotypes[45,X、46,X,i(Xq) and 45,X/46,XX] (r =-0.551,-0.560,-0.622,all P ＜ 0.01), except for the group with the 45, X/46, X, i (Xq).Conclusions (1) In this study, the consti-tuent ratios of these 4 common chromosomal karyotypes were different from those in Europe and America's.(2)Patients with 45 ,X may have more severe symptoms than others.(3)The mean age on diagnosis was at least 3.0 years earlier when considered HSDS below-2.00 as an indicator for chromosomal karyotype screening,which would facilitate earlier diagnosis.

OBJECTIVETo establish a hyperphenylalaninemia related genes screening method using Ion Torrent Personal Genome Machine (PGM) for early detection and differential diagnosis of hyperphenylalaninemia (HPA).

METHODSThree children with known HPA mutations and a healthy control were used for setting up the method. Ten children with HPA with known mutations were recruited for validating the method. Ion Ampliseq PCR was used to amplify the 5' and 3' untranslated region, coding sequence, and flanking introns of PAH, GCH1, PTS, QDPR, and PCBD1 genes. After the enrichment with the Ion OneTouch system, the products were sequenced by PGM. Data from the PGM were processed with Torrent Suite v2.2 software package. All variations were confirmed by Sanger sequencing.

RESULTSFor the 4 samples, the PGM output was 94.22 Mb, with approximately 99.5% of reads mapping to the target regions. Among these samples, we detected 74 variations (28 positions) including 6 known mutations. Compared with database and results of Sanger sequencing, 55 (18 positions) polymorphisms and 13 (4 positions) false positive calls were confirmed. For the 10 samples, all the known mutations were successfully identified.

CONCLUSIONIon Torrent PGM sequencing is suitable for screening genetic mutation underlying HPA from the perspective of metabolic pathways, which can meet the clinical demand for individualized diagnosis and treatment.

Objective To explore the clinical effect of nasal intermittent positive pressure ventilation combined with caffeine on the prevention and treatment of premature infants with extubation failure.Methods Totally 50 infants with neonatal respiratory distress syndrome (NRDS) with gestational age less than 32 weeks were divided into control group (nasal continuous airway positive pressure ventilationplus aminophylline treatment) and observation group (nasal intermittent positive pressure ventilation combined with caffeine treatment).Clinical effect was compared between two groups.Results The incidence rate of complications in the observation group was 16％,which was significantly lower than 32％ in the control group (P ＜ 0.05).There was no significant difference in blood gas indexes between the two groups after treatment of one hour,and the blood gas indexes after treatment of 12 hours in the observation group were significantly better than the control group (P ＜ 0.05).Conclusion Nasal intermittent positive pressure ventilation combined with caffeine can significantly improve the blood gas indexes and reduce the incidence rate of complications in premature infants with extubation failure.

Objective To explore the clinical effect of nasal intermittent positive pressure ventilation combined with caffeine on the prevention and treatment of premature infants with extubation failure.Methods Totally 50 infants with neonatal respiratory distress syndrome (NRDS) with gestational age less than 32 weeks were divided into control group (nasal continuous airway positive pressure ventilationplus aminophylline treatment) and observation group (nasal intermittent positive pressure ventilation combined with caffeine treatment).Clinical effect was compared between two groups.Results The incidence rate of complications in the observation group was 16％,which was significantly lower than 32％ in the control group (P ＜ 0.05).There was no significant difference in blood gas indexes between the two groups after treatment of one hour,and the blood gas indexes after treatment of 12 hours in the observation group were significantly better than the control group (P ＜ 0.05).Conclusion Nasal intermittent positive pressure ventilation combined with caffeine can significantly improve the blood gas indexes and reduce the incidence rate of complications in premature infants with extubation failure.

Objective:To explore the distribution of the copy number of survival motor neuron gene 2 ( SMN2) and the transcript level of the full-length SMN2 ( fl-SMN2) transcript level in patients with type 1-3 spinal muscular atrophy (SMA), and to evaluate their influences on disease severity, progression, and prognosis. Methods:It was a retrospective study involving 78 therapy-naive SMA patients with SMN1 gene homozygous deletion who were diagnosed and treated in the Capital Institute of Pediatrics from January 2019 to December 2021.Cross-sectional clinical data, including age at onset, motor milestones, and complications were recorded.They were followed up for monitoring motor function degeneration and survival.The copy number of SMN2 and the transcript level of fl-SMN2 were detected.Differences between groups were compared by the Student′s t-test or One- Way ANOVA or Chi- square test.Kaplan-Meier analysis was used for survival analysis, and Kendall′ s tau- c was performed to assess the correlation of these two biomarkers with SMA phenotypes, age at onset, motor milestones, and survival. Results:Of the 78 SMA patients, there were 17 cases (21.8%) of type 1, 34 cases(43.6%) of type 2, and 27 cases(34.6%) of type 3.Seven cases(41.2%) type 1 SMA patients died, with a median survival time of 11 months, and no deaths were observed in type 2 and type 3 SMA patients.There was a significant difference in the median age at onset among SMA patients with 2, 3, and 4 copies of SMN2 (1.8, 12.0, and 24.0 months, respectively; F=4.943, P=0.01). The mean transcript level of fl-SMN2 in type 1, 2 and 3 SMA patients were 196.25±68.79, 331.21±108.79 and 455.69±122.27, respectively ( F=37.154, P<0.001). The survival rate of SMA with 2 SMN2 copies at 1, 2, and 5 years were 50.5%, 0, and 0, respectively, and their median survival age was 7 months.The survival rate of SMA with 3 and 4 SMN2 copies at 5 years were 97.4% and 100.0%, respectively.Moreover, a negative correlation was observed between the transcript level of fl-SMN2 and phenotype severity ( Kendall′ s tau- c=-0.444, P<0.001), and the transcript level of fl-SMN2 of the survival group was much higher than that of the death group (342.93±125.74 vs.212.14±92.31). More copies of SMN2 and higher transcript level of fl- SMN2 indicated more motor function acquisitions (head control, sitting and walking) ( P<0.001). In addition, there was a significant difference in the transcription level of fl-SMN2 between the undegenerated group and the degenerated group in sitting and standing ( F=5.432, P=0.023 and F=4.315, P=0.047, respectively). Conclusions:Both the copy number of SMN2 and the transcript level of fl-SMN2 are correlated with SMA severity, survival, and motor milestones, serving as valuable biomarkers for evaluating phenotypic severity of SMA.The transcript level of fl-SMN2 s may play an important role in the degeneration of sitting and standing.

Objective:To explore application status and development trend of spinal muscular atrophy (SMA) genetic diagnosis technology based on the national rare diseases registry system of China.Method:A total of 200 SMA children registered at the Capital Institute of Pediatrics from July 2016 to December 2018 were included in this retrospective cross-sectional survey. The basic data, clinical subtypes, genotypes, and related genetic testing information of SMA children were obtained by checking SMA registration information, genetic testing reports, and also by telephone follow-up. The patient number and the composition of different genetic diagnosis technologies were analyzed by the stratification of genetic testing at various time. The correlation between the proportion of genetic diagnosis technology and genetic testing time was analyzed with Pearson correlation analysis.Result:There were 3 SMA cases with incomplete data, the remaining 197 SMA cases were included in this study. There were 37 (18.8%), 115 (58.4%) and 45 (22.8%) patients with type Ⅰ, Ⅱ and Ⅲ SMA, respectively. There were 185 cases of SMN1 homozygous deletion (93.9%), and 12 cases with compound heterozygotes (6.1%). Seven SMA-related genetic technologies were used from 2004 to 2017. MLPA accounted for 54.1% (100/185) used approach, followed by PCR-RFLP and first-generation sequencing, which accounted for 22.7% (42/185) and 10.3% (19/185), respectively. Nine, 6, 5 and 4 cases were tested with AS-PCR, qPCR, WES and DHPLC, respectively (2.2%-4.9%). The proportion of MLPA increased gradually since 2010 ( r=0.95, P<0.05), while PCR-RFLP declined gradually since 2004 ( r=-0.99, P<0.05). No correlation was found between technology and testing time for other genetic testing technologies ( P>0.05). The proportion of quantitative genetic technologies (MLPA, qPCR and DHPLC) increased gradually since 2010 ( r=0.94, P<0.05), and qualitative genetic technologies (PCR-RFLP, first-generation sequencing, AS-PCR and WES) decreased gradually since 2004 ( r=-0.94, P<0.05). The duplication detection rates of homozygous deletion and compound heterozygous mutation were 12.4% (23/185) and 41.7% (5/12), respectively (χ 2=5.86, P<0.05). During 2008-2015, the proportion of "the reports of both copy numbers of SMN1 gene and SMN2 gene" increased from 56.8% (21/37) in 2008-2015 to 69.1% (56/81) in 2016-2017. Conclusion:Genetic diagnosis of SMA has gradually developed from qualitative detection technology to quantitative detection technology, such as MLPA and qPCR, in China. In more and more SMA quantitative test reports, quantitative results of SMN2 gene are also provided in addition to quantitative results of SMN1 gene.

Objective:To explore the characteristics of SMN1 gene variants and carry out functional verification for two children with Spinal muscular atrophy (SMA). Methods:Two male children with complicated SMA diagnosed at the Children′s Hospital Affiliated to Capital Institute of Pediatrics respectively in July 2021 and April 2022 due to delayed or retrograde motor development were selected as the study subjects. Clinical data of the children were collected. Primary culture of skin fibroblasts was carried out, and peripheral blood samples were collected from both children and their parents. Multiplex ligation-dependent probe amplification, combined long-range PCR and nested PCR, and Sanger sequencing were carried out to detect the copy number and variants of the SMN1 gene. Absolute quantitative real-time PCR, Western blotting and immunofluorescence were used to determine the transcriptional level of the SMN gene, expression of the SMN protein, and the number of functional SMN protein complexes (gems body), respectively. This study was approved by Medical Ethics Committee of the Children′s Hospital Affiliated to Capital Institute of Pediatrics (Ethics No. SHERLLM2021009). Results:Child 1, a 1-year-old boy, was clinically diagnosed with type 1 SMA. Child 2, a 2-and-a-half-year-old boy, was clinically diagnosed with type 3 SMA. Both children were found to harbor a paternally derived SMN1 deletion and a maternally derived SMN1 gene variant, namely c. 824G>T (p.Gly275Val) and c. 884A>T (p.*295Leu). Compared with the normal controls and carriers, the levels of full-length SMN1 transcripts in their peripheral blood and skin fibroblast cell lines were significantly decreased ( P<0.05), and the levels of SMN protein normalized to that of β-actin, and the numbers of gems bodies in the primary fibroblast cells were also significantly lower ( P<0.05). Based on the guidelines from the American College of Medical Genetics and Genomics, both variants were classified as likely pathogenic (PS3+ PM3+ PM5+ PP3; PS3+ PM3+ PM4+ PP3). Following the diagnosis, both children had received nusinersen treatment. Although their motor function was improved, child 1 still died at the age of 2 due to severe pulmonary infection. The walking ability of child 2 was significantly improved, and his prognosis appeared to be good. Conclusion:Two cases of clinically complicated SMA have been confirmed by genetic testing and experimental studies, which has provided a reference for their accurate treatment.