BackgroundThe outcome of preterm infants has been varied in different hospitals and regions in developing countries. Regular clinical monitor are needed to know the effects of health care. This study aimed to describe the survival and morbidity rates of extreme to very preterm infants in 15 neonatal-intensive care hospitals in China.MethodsData were collected from January 1, 2013 to December 31, 2014 for preterm neonates with gestational age (GA) between 24 and 31 complete weeks born in hospitals from our collaborative study group. The primary outcomes were survival and major morbidities prior to hospital discharge. Major morbidities included bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), patent ductus arteriosus (PDA) and sepsis. Mutivariate logistic regression was used to analyze the risk factor influencing on the outcomes.ResultsThe preterm birth rate was 9.9 % (13 701/138 240). The proportion of extreme to very preterm infants was 1.1 % and 11.8 % respectively. The survival rate prior to discharge was increased with increasing GA (0, 24 weeks; 28 %, 25 weeks; 84.8 %, 26 weeks; 83.5 %, 27 weeks; 87.4 %, 28 weeks; 90.7 %, 29 weeks; 93.9 %, 30 weeks; 96 %, 31 weeks). Rate of survival and without severe morbidity according to GA were 0 at 24 weeks, 8 % at 25 weeks, 60.6 % at 26 weeks; 53.2 % at 27 weeks; 62.3 % at 28 weeks; 67.9 % at 29 weeks; 79.1 % at 30 weeks, 85.8 % at 31 weeks respectively. Rate of antenatal steroid use was 56 %. The antenatal steroid use was lower in GA < 28 weeks infants than that in GA between 28 and 32 weeks (28–44.3 % vs 49.7–60.1 %, P < 0.05). Infants at the lowest GAs had a highest incidence of morbidities. Overall, 58.5 % had respiratory distress syndrome, 12.5 % bronchopulmonary dysplasia, 3.9 % necrotizing enterocolitis, 15.4 % intraventricular hemorrhage, 5.4 % retinopathy of prematurity, 28.4 % patent ductus arteriosus, and 9.7 % sepsis. Mortality and morbidity were influenced by gestational age (OR = 0.891, 95 % CI: 0.796–0.999, p = 0.0047 and OR = 0.666, 95 % CI: 0.645–0.688, p = 0.000 respectively), birth weight (OR = 0.520, 95 % CI: 0.420–0.643, p = 0.000 and OR = 0.921, 95 % CI: 0.851–0.997, p = 0.041 respectively), SGA (OR = 1.861, 95 % CI: 1.148–3.017, p = 0.012 and OR = 1.511, 95 % CI: 1.300–1.755, p = 0.000 respectively), Apgar score <7 at 5 min (OR = 1.947, 95 % CI: 1.269–2.987, p = 0.002 and OR = 2.262, 95 % CI: 1.950–2.624, p = 0.000 respectively). The survival rate was increased with more prenatal steroid use (OR = 1.615, 95 % CI: 1.233–1.901, p = 0.033).ConclusionAlthough most of the preterm infants with GAs ≥26 weeks survived, a high complication in survivors still can be observed. Rate of survival of GAs less than 26 weeks was still low, and quality improvement methods should be used to look into increasing the use of antenatal steroids in the very preterm births.

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Background Duchenne Muscular Dystrophy (DMD) is the most common muscle disease in children, and there are no effective therapies for DMD or Becker Muscular Dystrophy (BMD). Currently, targeted gene therapy treatments have emerged. As a result, genetic diagnosis is the basis of treatment. In addition, genetic and prenatal diagnosis significantly reduces their incidence rates. This study combines the application of multiplex ligation-dependent probe amplification technology (MLPA) and “next-generation” sequencing technology (NGS) as the most economical and efficient method of diagnosis. Therefore, in the diagnosis of DMD/BMD, patients’ MLPA data are first used to detect DMD gene deletions or duplications, and NGS and Sanger sequencing are then applied to exclude MLPA-negative samples. Meanwhile, polymerase chain reaction (PCR) is used to detect single exon deletions to exclude false-positives in MLPA caused by point mutations. Methods In this study, we recruited 1051 proband families of DMD from 2016 to 2018 and had access to information that could identify individual participants during or after data collection. Patients who were diagnosed with DMD were first tested by MLPA. MLPA results with single exon deletions were validated with PCR amplification and Sanger sequencing. The negative results of MLPA were further analysed with NGS and validated by Sanger sequencing. For novel missense mutations, phenotype-genotype correlations were analysed using PolyPhen2 and mutation taster. All methods were performed in accordance with the relevant guidelines and regulations. Results DMD mutations were identified in 1029 families (97.91%, 1029/1051). Large deletions, duplications, and small mutations accounted for 70.41% (740/1051), 8.28% (87/1051), and 19.12% (201/1051) of all cases, respectively. There were 205 small mutation types, 53 of which were novel. The rate of de novo mutations was 39.45% (187/474) and was higher in large duplications (49.53%, 157/317). Among 68 asymptomatic patients (< 3 years old) with unexplained persistent hyperCKaemia upon conventional physical examination, 63 were diagnosed as DMD/BMD according to genetic diagnosis. Conclusion Our results expand the spectrum of DMD mutations, which could contribute to the treatment of DMD/BMD and provide an effective diagnosis method. Thus, the combination of MLPA, NGS and Sanger sequencing is of great significance for family analysis, gene diagnosis and gene therapy.

Abundant decidual natural killer (dNK) cells at the maternal-fetal interface are important during early pregnancy. However, functional subsets of dNK cells remain poorly understood. We describe a CD49a+PBX homeobox 1 (PBX1)+ dNK cell subset that promotes fetal development in humans and mice. The expression of PBX1 in dNK cells is up-regulated via the activated AKT1 pathway through the interaction of major histocompatibility complex G with the immunoglobulin-like transcript 2 receptor. PBX1 drives pleiotrophin and osteoglycin transcription in dNK cells, further promoting fetal development. Decreased PBX1 expression or the PBX1G21S mutant correlated with fetal growth restriction and pregnancy failure in patients with unexplained recurrent spontaneous abortion (URSA). Inactivation of Pbx1 in mouse dNK cells impairs fetal development by decreasing growth-promoting factors from CD49a+PBX1+ dNK cells. Impairment of PBX1 in dNK cells has positive correlation with URSA pathogenesis and may provide a potential marker for this condition.

BackgroundTargeted next-generation sequencing (NGS) is a cost-effective approach for rapid and accurate detection of genetic mutations in patients with suspected genetic disorders, which can facilitate effective diagnosis.Methodology/Principal FindingsWe designed a capture array to mainly capture all the coding sequence (CDS) of 2,181 genes associated with 561 Mendelian diseases and conducted NGS to detect mutations. The accuracy of NGS was 99.95%, which was obtained by comparing the genotypes of selected loci between our method and SNP Array in four samples from normal human adults. We also tested the stability of the method using a sample from normal human adults. The results showed that an average of 97.79% and 96.72% of single-nucleotide variants (SNVs) in the sample could be detected stably in a batch and different batches respectively. In addition, the method could detect various types of mutations. Some disease-causing mutations were detected in 69 clinical cases, including 62 SNVs, 14 insertions and deletions (Indels), 1 copy number variant (CNV), 1 microdeletion and 2 microduplications of chromosomes, of which 35 mutations were novel. Mutations were confirmed by Sanger sequencing or real-time polymerase chain reaction (PCR).Conclusions/SignificanceResults of the evaluation showed that targeted NGS enabled to detect disease-causing mutations with high accuracy, stability, speed and throughput. Thus, the technology can be used for the clinical diagnosis of 561 Mendelian diseases.

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Background Alport syndrome (AS) is an inherited progressive renal disease caused by mutations in COL4A3, COL4A4, and COL4A5 genes. The large sizes of these genes and the absence of mutation hot spots have complicated mutational analysis by routine PCR‐based approaches. In recent years, the development of next‐generation sequencing (NGS) has made possible the time‐ and cost‐effective and accurate analysis of the three genes in a single step. Methods Here, we analyze COL4A3, COL4A4, and COL4A5 simultaneously in 29 AS patients using NGS. Candidate mutations were validated by classic Sanger sequencing and Real‐time PCR. Results Twenty two new mutations and 10 known mutations were detected. Of those novel mutations, 18, 3, and 1 mutations were detected in COL4A5, COL4A4, and COL4A3, respectively. Twenty six patients showed X‐linked inheritance, one showed autosomal recessive inheritance and two showed digenic inheritance (DI). Conclusion A comparison of the clinical manifestations caused by different types of mutations in COL4A5 suggested that large fragment mutations are relatively more severe than the other missense mutations and AS by some mutations may show inter‐ and intra‐familial phenotypic variability. It is important to consider these transmission patterns in the clinical evaluation according to the results of genetic testing, especially for DI. Twenty two new mutations can expand the genotypic spectrum of AS.

BackgroundPhenylketonuria (PKU), which primarily results from a deficiency of phenylalanine hydroxylase (PAH), is one of the most common inherited inborn errors of metabolism that impairs postnatal cognitive development. The incidence of various PAH variations differs by race and ethnicity. The aim of the present study was to characterize the PAH gene variants of a Han population from Northern China.MethodsIn total, 655 PKU patients and their families were recruited for this study; each proband was diagnosed both clinically and biochemically with phenylketonuria. Subjects were sequentially screened for single-base variants and exon deletions or duplications within PAH via direct Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA).ResultsA spectrum of 174 distinct PAH variants was identified: 152 previously documented variants and 22 novel variants. While single-base variants were distributed throughout the 13 exons, they were particularly concentrated in exons 7 (33.3%), 11 (14.2%), 6 (13.2%), 12 (11.0%), 3 (10.4%), and 5 (4.4%). The predominant variant was p.Arg243Gln (17.7%), followed by Ex6-96A > G (8.3%), p.Val399 = (6.4%), p.Arg53His (4.7%), p.Tyr356* (4.7%), p.Arg241Cys (4.6%), p.Arg413Pro (4.6%), p.Arg111* (4.4%), and c.442-1G > A (3.4%). Notably, two patients were also identified as carrying de novo variants.ConclusionThe composition of PAH gene variants in this Han population from Northern China was distinct from those of other ethnic groups. As such, the construction of a PAH gene variant database for Northern China is necessary to lay a foundation for genetic-based diagnoses, prenatal diagnoses, and population screening.Electronic supplementary materialThe online version of this article (10.1186/s12881-017-0467-7) contains supplementary material, which is available to authorized users.