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 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.

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.

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 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.

Objectives:To investigate the effect of fat suppression (FS) T 2WI on the interobserver agreement and diagnostic performance of clear cell likelihood score version 2.0 (ccLS v2.0) for clear cell renal cell carcinoma (ccRCC). Methods:In this retrospective study, the MR images of 111 patients with pathologically confirmed small renal masses (SRM) from January to December 2021 were analyzed in the First Medical Centre, Chinese PLA General Hospital. Of the 111 SRM, 82 cases were ccRCC and 29 cases were non-ccRCC. Two radiologists independently assessed ccLS scores based on T 2WI signal intensity (hypointense, isointense, hyperintense) and other MRI features (ccLS-T 2WI). After a one-month interval, the ccLS scores were independently evaluated utilizing the frequency-selective saturation FS-T 2WI and other MRI features (ccLS-FS-T 2WI). Fisher′s exact test was used to compare the difference in SRM signal intensity on T 2WI and FS-T 2WI. The weighted Kappa test was performed to assess the interobserver agreement of the two radiologists, and differences in the weighted Kappa coefficients were compared using the Gwet consistency coefficient. Receiver operating characteristic curves were drawn to evaluate the diagnostic performance of ccLS-T 2WI and ccLS-FS-T 2WI in diagnosing ccRCC, and the area under the curve (AUC) was compared utilizing the DeLong test. Results:The signal intensity of 111 SRM on T 2WI and FS-T 2WI had statistically significant difference (χ 2=126.33, P<0.001), consistent in 88 cases (79.3%) and varied in 23 cases (20.7%). The weighted Kappa coefficient of ccLS-T 2WI was 0.57 (95%CI 0.45-0.69) between the two radiologists, and the weighted Kappa coefficient of ccLS-FS-T 2WI was 0.55 (95%CI 0.42-0.67), and the difference was not statistically significant ( t=-0.65, P=0.520). The AUC of ccLS-T 2WI for ccRCC diagnosis was 0.92 (95%CI 0.86-0.97), while the AUC of ccLS-FS-T 2WI for ccRCC diagnosis was 0.91 (95%CI 0.85-0.96), and the difference was not statistically significant ( Z=1.50, P=0.133). Conclusions:The interobserver agreement and diagnostic performance of ccLS v2.0 based on T 2WI and FS-T 2WI sequences for ccRCC are comparable, and FS-T 2WI is applicable for the clinical application of ccLS v2.0.

Objective:To investigate the clinical and MRI features of the mixed epithelial and stromal tumor family (MESTF) of the kidney.Methods:From January 2009 to September 2021, 42 patients with pathologically-proven MESTF from the First Medical Center of Chinese PLA General Hospital were collected in this retrospective study. Clinical information, MRI features, and pathological results were documented. According to the Bosniak classification (BC) version 2019, all MESTFs were divided into cystic MESTFs (36 cases) and solid-cystic MESTFs (6 cases). The R.E.N.A.L. nephrometry score (RNS), lesion size, laterality, location, margin, shape, growth pattern, presence of protruding into renal sinus, hemorrhage, and enhancement pattern were evaluated and documented. Based on BC versions 2005 and 2019, all the cystic MESTFs were assessed and divided into low (Ⅰ, Ⅱ, ⅡF) and high (Ⅲ, Ⅳ) grades. The independent sample t test or Mann-Whitney U test were performed to compare age, RNS, and lesion size between cystic MESTFs and solid-cystic MESTFs. Pearson χ 2 test, continuity-adjusted χ 2 test or Fisher exact probability test were utilized to evaluated the differences of clinical and MRI features and the distribution of low or high grades in two versions of BC. Results:Forty-two MESTFs were unilateral and solitary masses, 25 males and 17 females, with a mean age of (41±13) years old. Compared to solid-cystic MESTFs, cystic MESTFs were prone to demonstrate endophytic growth pattern (χ 2=17.77, P<0.001), and no significant differences in other clinical and MRI features were observed between cystic and solid-cystic MESTFs (all P>0.05). There were 7 low-grade and 29 high-grade tumors in the BC version 2005, respectively. Meanwhile, 24 low-grade and 12 high-grade tumors in the BC version 2019, respectively. The distribution of low or high-grade tumors in the two versions of BC had a statistically significant difference (χ 2=16.37, P<0.001). Conclusion:MESTFs demonstrated middle-age onset and no gender predilection. Cystic MESTFs are more likely to exhibit endophytic growth pattern with low-grade classification in BC system version 2019.

Exocrine pancreatic insufficiency is a commom complication after pancreatic operation with high morbidity.At present,surgeons have insufficient understanding of it,and there is no internationally normalized standard for the diagnosis and treatment of exocrine pancreatic insufficiency.Through systematic reviewing of the relevant literature,this review summarizes the research progress of exocrine pancreatic insufficiency after pancreatic operation,including the definition of exocrine pancreatic insufficiency,aetiological agent,diagnosis,treatment,prevention,and morbidity of pancreatic exocrine insufficiency in different surgical procedures,in order to provide a reference for the improvement of diagnosis and treatment of exocrine pancreatic insufficiency in the future.

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 investigate the impact of the interval period between biopsy and MR examination on tumor detection and extraprostatic extension (EPE) assessment for prostate cancer (PCa) using multi-parametric MRI (mpMRI).Methods:The study was cross-sectional and retrospectively included 130 patients with PCa who underwent RP and preoperative systematic biopsies followed by mpMRI between January 2021 and December 2022 in the First Medical Center of Chinese PLA General Hospital. Patients were divided into 3 groups according to interval following biopsy (group A,<3 weeks, 31 cases; group B, 3-6 weeks, 67 cases; group C,>6 weeks, 32 cases). The percentages of hemorrhage volume in the total prostate were drawn on T 1WI and calculated. The junior, senior and expert radiologists independently localized the index lesions and calculated the accuracy for tumor detection, in addition to assessing the probabilities of EPE according to EPE grade. The correlation between the hemorrhage extent and interval was analyzed using the Spearman correlation coefficient. The accuracy for tumor detection was compared using χ2 test among groups. The diagnostic performance of the radiologists for EPE prediction was assessed using the receiver operating characteristic curve, and the differences between the corresponding area under the curve (AUC) were compared using the DeLong test. Results:The percentage of hemorrhage was correlated with the interval between biopsy and MR examination ( r=-0.325, P<0.001). The detection accuracy of junior radiologist was 83.9% (26/31), 76.1% (51/67), and 78.1% (25/32) in group A, B and C, respectively; no differences were observed in the detection accuracy among three groups ( χ2=0.76, P=0.685). The detection accuracy of senior radiologist was 83.9% (26/31), 80.6% (54/67), and 71.9% (23/32) in 3 groups with no differences ( χ2=1.53, P=0.464). The detection accuracy of expert radiologist was 80.6% (25/31), 77.6% (52/67), and 93.8% (30/32) with no differences ( χ2=3.95, P=0.139). The AUC (95% CI) for predicting EPE were 0.830 (0.652-0.940), 0.704 (0.580-0.809), 0.800 (0.621-0.920) in the group A, B and C for junior radiologist; 0.876 (0.708-0.966), 0.768 (0.659-0.863), 0.896 (0.736-0.975) for senior radiologist; and 0.866 (0.695-0.961), 0.813 (0.699-0.895), 0.852 (0.682-0.952) for expert radiologist, respectively. No differences were observed among the subgroups in each radiologist ( P>0.05). Conclusion:The interval period does not significantly affect the detection accuracy and EPE assessment of PCa using mpMRI. There is probably no necessity for prolonged intervals following systematic biopsy to preserve the clarity of MRI interpretation for PCa.