Objective To observe the value of fetal MRI in diagnosis of duodenal obstruction(DO).Methods A total of 35 fetuses with suspected DO according to MRI were retrospectively included.The length and the maximum diameter of the dilated duodenum were measured,so as site(categorized in descending order from proximal to distal as descending segment,horizontal segment and ascending duodenum/proximal jejunum)and the degree of obstruction(complete or incomplete)were assessed.Taken findings of labor induction specimen,postnatal neonatal surgery or follow-up data as standards,the positive predictive value(PPV)of MRI for diagnosing fetal DO was calculated,while the correlations of the measured parameters of dilated duodenum and the confirmed obstruction site/degree were analyzed.Results Among 35 fetuses,DO was confirmed in 34 fetuses,yielding an overall PPV of 97.14％(34/35)for MRI.In 34 fetuses with confirmed DO,there were 23 with descending DO(DDO),4 with horizontal DO(HDO)and 7 with ascending DO/proximal jejunum obstruction(ADO/PJO),including 12 with complete DO and 22 with incomplete DO.PPV of MRI for diagnosing DDO,HDO and ADO/PJO was 87.50％(21/24),50.00％(2/4)and 100％(7/7),respectively,for diagnosing complete and incomplete DO was 90.00％(9/10)and 84.00％(21/25),respectively.Both the length and the maximum diameter of fetal proximal dilated duodenum showed on MRI were positively correlated with the actual obstruction site(from proximal to distal)(rs=0.736,P＜0.001;rs=0.424,P=0.011,respectively),but had no significant rank correlation with the degree of obstruction(rs=-0.216,P=0.212;rs=-0.285,P=0.097,respectively).Conclusion Fetal MRI could effectively evaluate the length and the maximum diameter of dilated duodenum hence indicating the level and degree of DO.

Objective To observe the value of fetal MRI in diagnosis of duodenal obstruction(DO).Methods A total of 35 fetuses with suspected DO according to MRI were retrospectively included.The length and the maximum diameter of the dilated duodenum were measured,so as site(categorized in descending order from proximal to distal as descending segment,horizontal segment and ascending duodenum/proximal jejunum)and the degree of obstruction(complete or incomplete)were assessed.Taken findings of labor induction specimen,postnatal neonatal surgery or follow-up data as standards,the positive predictive value(PPV)of MRI for diagnosing fetal DO was calculated,while the correlations of the measured parameters of dilated duodenum and the confirmed obstruction site/degree were analyzed.Results Among 35 fetuses,DO was confirmed in 34 fetuses,yielding an overall PPV of 97.14％(34/35)for MRI.In 34 fetuses with confirmed DO,there were 23 with descending DO(DDO),4 with horizontal DO(HDO)and 7 with ascending DO/proximal jejunum obstruction(ADO/PJO),including 12 with complete DO and 22 with incomplete DO.PPV of MRI for diagnosing DDO,HDO and ADO/PJO was 87.50％(21/24),50.00％(2/4)and 100％(7/7),respectively,for diagnosing complete and incomplete DO was 90.00％(9/10)and 84.00％(21/25),respectively.Both the length and the maximum diameter of fetal proximal dilated duodenum showed on MRI were positively correlated with the actual obstruction site(from proximal to distal)(rs=0.736,P＜0.001;rs=0.424,P=0.011,respectively),but had no significant rank correlation with the degree of obstruction(rs=-0.216,P=0.212;rs=-0.285,P=0.097,respectively).Conclusion Fetal MRI could effectively evaluate the length and the maximum diameter of dilated duodenum hence indicating the level and degree of DO.

Spinal muscular atrophy（SMA），an autosomal recessive genetic disease characterized by progressive weakness and atrophy of the proximal limbs caused by degeneration of motor neurons in the anterior horn of the spinal cord，can affect multiple systems such as respiratory，digestive，and skeletal systems. Untreated children with severe type 1 SMA usually die within 2 years of age. In recent years，the treatment of SMA has developed rapidly，and a variety of drugs have been approved to benefit patients. However，none of the existing therapeutic drugs or regimens can achieve a complete cure. Therefore，the combination of different therapeutic drugs and the research and development of new drugs may be the way forward for the treatment of SMA. The latest progress of therapeutic drugs and combination therapy in SMA are summarized in this review，which may be helpful for guiding the treatment of SMA.

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.

Objective:To investigate clinical characteristics of and genetic variants in the NF1 gene in children with neurofibromatosis type 1 (NF1) .Methods:Clinical data were collected from 22 children with NF1, who were admitted to the Department of Dermatology, Children's Hospital, Capital Institute of Pediatrics from January 2022 to September 2023, and were analyzed. Next-generation sequencing was performed to detect NF1 mutations in the probands, and the variants were verified in the family members by Sanger sequencing. A homology modeling software was used to predict the three-dimensional protein structure, and analyze the characteristics of gene mutations.Results:Among the 22 children with NF1, there were 14 males and 8 females, and they were aged from 3 months to 12 years at the clinic visit. All the 22 children presented with multiple café-au-lait spots, and their age at onset ranged from birth to 2 years. Nine patients were accompanied by freckles in the axillary or inguinal regions, 2 by cutaneous neurofibromas, 2 by juvenile xanthogranuloma, 2 by learning disabilities, and Lisch nodules of the iris, central precocious puberty and scoliosis occurred in 1 case each; 5 cases showed characteristic manifestations of neurofibroma on brain magnetic resonance imaging. A total of 5 types of NF1 gene variants were identified in the 22 patients, including complete heterozygous deletion of the NF1 gene (1 patient), missense variants (4 patients, one of whom carried 2 types of missense variants), frameshift variants (8 patients), nonsense variants (6 patients), and classical splicing variants (3 patients). Among the 22 variants, 7 were unreported variants, including c.758T>A (p.Val253Glu), c.2360dupC (p.Thr788Asnfs*5), c.5513T>G (p.Leu1838*), c.2774dupT (p.Leu925Phefs*11), c.6894dupT (p.Val2299Cysfs*7), c.6882_6883delCT (p.Phe2295Leufs*10), and c.6448A>T (p.Lys2150*). Of the unreported variants, 6 were frameshift or nonsense variants leading to different degrees of truncated protein expression, and severely affecting protein function; based on the three-dimensional protein structure prediction analysis, it was uncertain if the missense variant c.758T>A (p.Val253Glu) affected protein conformation. In 2 children, the NF1 variants were inherited from their mothers; 1 child carried 2 NF1 missense variants, 1 of which was a spontaneous mutation potentially causing the disease, while the other one with unknown pathogenicity was inherited from the phenotypically normal father; the remaining 19 children all carried spontaneous mutations.Conclusions:Children with NF1 mainly present with multiple café-au-lait spots at the early stage, and some characteristic manifestations such as cutaneous neurofibroma, juvenile xanthogranuloma, and Lisch nodules of the iris can also occur. NF1 gene pathogenic variants are complex and diverse, and 22 variants were identified in this study, enriching the spectrum of NF1 gene variants.

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.

Antisense oligonucleotides(ASOs)are small sequences of DNA or RNA able to target mRNA transcripts resulting in change or reduction in the expression of target genes, and became an emerging class of therapeutic drugs.With its high specific, adaptable, and low side effects, ASO drugs are widely used in rare diseases, tumor, inflammatory diseases, cardiovascular disease, and infectious diseases.Recent numerous advancements in ASO sequence design, chemical modifications and delivery methods, significant breakthroughs have been made in the treatment and ASOs become an ideal candidate therapies for neurodegenerative diseases.

Objective:To investigate the coverage rate and the adverse reactions of National Immunization Program vaccines in children with spinal muscular atrophy (SMA).Methods:A cross-sectional retrospective cohort study was carried out from July 2016 to June 2019, 192 children (116 boys and 76 girls) with SMA registered by Capital Institute of Pediatrics and 191 healthy children (115 boys and 76 girls) vaccinated in Chaoyang Olympic Village Community Health Service Center from July 2016 to December 2018 were included. Questionnaire survey was designed to investigate the vaccination coverage rate and associated adverse events. The t-test and χ 2 test were used to compare the difference between SMA patients and healthy children. Results:The coverage rate of age-appropriate immunization in SMA children was 62.0% (119/192) in general, and were 52.2% (12/23), 55.7% (68/122), and 83.0% (39/47) for SMA type 1-3 patients, respectively (χ 2=12.23, P=0.002). The vaccination coverage rates of Bacillus Calmette-Guerin (BCG) vaccine, the 3 rd dose of hepatitis B, the 3 rd dose of polio, the 3 rd dose of diphtheria-pertussis-tetanus, the 1 st dose of meningococcal polysaccharide group A, the 1 st dose of measles or measles and rubella vaccine, the 1 st dose of Japanese encephalitis vaccine, hepatitis A, measles-mumps-rubella, and group A+C meningococcal polysaccharide vaccine were 100.0% (192 cases), 94.3% (181 cases), 81.8% (157 cases), 88.5% (170 cases), 83.9% (161 cases), 76.6% (147 cases), 80.2% (154 cases), 68.2% (131 cases), 69.8% (134 cases), 54.7% (105 cases), respectively. Among the 73 patients who did not have their planned immunization completed, 57 cases (78.1%) gave up the vaccination due to parents′ concern of potential aggravation of their disease, and 16 cases (21.9%) had the plan discontinued by the immunization department because of the disease. Fever, local redness and swelling were the most common side-effects after vaccination both in SMA patients and healthy children (19.8% (38/192) vs. 18.8% (36/191) , χ 2=0.055, P=0.815). The main abnormal reactions of vaccination were rash and neurovascular edema, without significant difference between these two groups (2.6% (5/192) vs. 3.7% (7/191), χ 2=0.355, P=0.551). The coverage rate of Influenza and pneumococcal vaccine in SMA patients were 22.4% (43 cases) and 31.8% (61 cases), respectively. The incidence of pneumonia in the SMA patients decreased from 59.0% (23/39) to 41.0% (16/39) after vaccination. And none of the Influenza vaccinated patients had the flu in the year of vaccination. Conclusions:The coverage rate of National Immunization Program vaccines in the SMA children is low, especially in type 1 SMA patients, which is mainly due to their guardians′ concern of potential adverse events, even though the incidence of adverse reactions is similar in SMA patients and healthy children. Influenza and pneumococcal vaccine can reduce the risk of pneumonia and flu in children with SMA effectively.

Objective:To analyze the effect of comprehensive health management on the prognosis of children with type Ⅰ spinal muscular atrophy (SMA).Methods:Eighty patients with type Ⅰ SMA (39 males and 41 females) visited-Capital Institute of Pediatrics from January 2003 to December 2017, were enrolled in this case-control study retrospectively. They were divided into the health management group and the natural history group. Main statistical parameter, including demographic indicators, survival time, 2-year survival rate and incidence of complications were compared and analyzed. Patients were evaluated every 3-6 months. All data were processed by SPSS 19.0. Differences between the two groups were compared using rank sum test or chi square test. Survival analysis was performed by using Kaplan-Meier method, and survival difference test was performed by log-rank method.Results:Among 80 SMA patients, 14 cases (7 males and 7 females) were in the health management group and 66 cases (32 males and 34 females) in the natural history group. There was no statistically significant difference in gender ratio between the two groups (χ 2=0.01, P=0.918) . The ages of onset and death in the two groups were 2 (0-8) and 1 (0-14) month, 11 (5-17) and 6 (1-60) months, without statistically significant difference ( Z=0.91, 1.19; P=0.386, 0.116) . As of the follow-up date (June 2019) , 10 patients died and 4 survived in the health management group, while 62 (93.9%) died and 4 (6.1%) survived in the natural history group (χ 2=6.50, P=0.011) . The median survival time in the health management group was 12 months, and the 1, 2 and 3-year survival rates were 77.9%, 54.5% and 34.1%, respectively. The median survival time of the natural history group was 6 months, and the 1, 2 and 3-year survival rates were 48.5%, 15.2% and 7.6%, respectively. For the two groups, the difference in survival rates was statistically significant (χ 2=9.11 P=0.003). The incidence rate of pneumonia combined with respiratory failure in the health management group was lower than that in the natural history group. Conclusion:Active health management can improve the survival rate of type Ⅰ SMA patients, reduce the incidence of complications, and also improve the prognosis of patients.