Exome sequencing and functional analysis identifies a novel mutation in <em>EXT1</em> gene that causes multiple osteochondromas

Multiple osteochondromas (MO) is an inherited skeletal disorder, and the molecular mechanism of MO remains elusive. Exome sequencing has high chromosomal coverage and accuracy, and has recently been successfully used to identify pathogenic gene mutations. In this study, exome sequencing followed by Sanger sequencing validation was first used to screen gene mutations in two representative MO patients from a Chinese family. After filtering the data from the 1000 Genome Project and the dbSNP database (build 132), the detected candidate gene mutations were further validated via Sanger sequencing of four other members of the same MO family and 200 unrelated healthy subjects. Immunohistochemisty and multiple sequence alignment were performed to evaluate the importance of the identified causal mutation. A novel frameshift mutation, c.1457insG at codon 486 of exon 6 of EXT1 gene, was identified, which truncated the glycosyltransferase domain of EXT1 gene. Multiple sequence alignment showed that codon 486 of EXT1 gene was highly conserved across various vertebrates. Immunohistochemisty demonstrated that the chondrocytes with functional EXT1 in MO were less than those in extragenetic solitary chondromas. The novel c.1457insG deleterious mutation of EXT1 gene reported in this study expands the causal mutation spectrum of MO, and may be helpful for prenatal genetic screening and early diagnosis of MO

The coupling and coordination between food production security and agricultural ecological protection in main food-producing areas of China

Food production security (FPS) and agricultural ecological protection (AEP) are both among the paramount issues affecting the country. There are multiple nonlinear interactions between the two systems, while fewer studies have focused on the interaction patterns between them. To realize China's national strategic goals of food security and ecological protection, the interaction between FPS and AEP needs to be analyzed. Based on the evaluation index system of the coupling and coordination between the two systems, this article analyzes the spatio-temporal differentiation and influencing factors in 13 main food-producing regions in China from 2009 to 2021 using the state-space method and spatial econometric model. The following three conclusions were found: First, the overall development levels of both FPS and AEP show an increasing trend, but regional differences are obvious. Second, the coupling coordination degree and stage of the two systems present an upward trend, but the overall development level remains low, with obvious regional differences: Liaoning is still on the imminent disorder stage, while Heilongjiang has taken the lead into the intermediate coordination stage. Third, the total power of grain machinery and the soybean corn planting ratio have a significant positive impact on the coupling and coordination between FPS and AEP. The results make up for the lack of research on coupling and coordination between FPS and AEP, and provide a feasible development path for exploring coordinated development of FPS and AEP in China's main food-producing areas

Comparison of Two Algorithms for Multiline Bus Dynamic Dispatching

Dynamic bus scheduling refers to adjusting the departure time according to the latest time-varying information or adjusting bus speed in the process of operation. These control strategies can prevent bus bunching and alleviate traffic pressure. The paper studies the multiline bus dynamic scheduling with consideration of departure time and speed meanwhile. The hyperheuristic algorithm is proposed, and low-level heuristics (LLH) operators are designed. The simulation experiment is performed for the passenger flow distribution of different strengths and types of different scenarios. By comparing the experimental results of genetic algorithm (GA) and hyperheuristic algorithm in solving different scenarios, the results show that in smooth, increasing, decreasing, and multiconvex passenger flow mode, the performance of the hyperheuristic algorithm is higher than that of GA. The promotion rate reaches 18∼28%, and especially the average value of the hyperheuristic algorithm designed under multiconvex passenger flow is up to 28.62%, significantly reducing passengers’ waiting time. By comparing the stability of the three passenger flow modes, the results illustrate that the stability of the hyperheuristic algorithm is lower than that of GA. For the smooth passenger flow mode, the stability of medium and lower density of GA is higher than that of the hyperheuristic algorithm. In comparison, the high-density stability of the hyperheuristic algorithm is better than that of GA

A novel homozygous insertion and review of published mutations in the NNT gene causing familial glucocorticoid deficiency (FGD)

Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder characterized by low levels of cortisol despite high adrenocorticotropin (ACTH) levels, due to the reduced ability of the adrenal cortex to produce cortisol in response to stimulation by ACTH. FGD is a heterogeneous disorder for which causal mutations have been identified in MC2R, MRAP, MCM4 and TXNRD2. Also mutations in STAR and CYP11A1 can sometimes present with a phenotype resembling FGD. Recently, it has been indicated that FGD can also be caused by mutations in NNT (nicotinamide nucleotide transhydrogenase). We identified a 6.67 Mb homozygous region harboring the NNT gene by SNP haplotyping in a 1-year old Dutch boy presenting with FGD, but without mutations in MC2R and MRAP. Exome-sequencing revealed a novel homozygous mutation (NM_012343.3: c.1259dupG) in NNT that was predicted to be disease-causing. The mutation is located in exon 9 and creates a frameshift leading to a premature stopcodon (p.His421Serfs*4) that is known to result in FGD. Both parents were shown to be heterozygous carriers. We reviewed the literature for all the reported NNT mutations and their clinical presentation. The median age of disease onset in 23 reported patients, including the present patient, was 12 months (range 3 dayse39 months). There was no difference in age of disease onset between truncating and nontruncating NNT mutations. Based on recent literature, we advise to monitor patients with FGD due to NNT mutations for possible combined mineralocorticoid insufficiency and extra-adrenal manifestations. (C) 2015 Elsevier Masson SAS. All rights reserved

Identification of a frameshift mutation in codon 486 of <i>EXT1</i> gene.

<p>(a) Sanger sequencing detected the inserted base in the <i>EXT1</i> gene of all affected subjects. Red arrowhead denotes the mutation position; (b) intron-exon structure of <i>EXT1</i> gene. Mutated exon is indicated by red arrowhead; (c) comparison of the functional domains of EXT1 proteins encoded by mutated and normal <i>EXT1</i> genes; (d) multiple sequence alignment of codon 485 to codon 487. Codon 486 is highly conserved across various vertebrates.</p

Immunohistochemisty screening of chondrocytes with functional EXT1 in the superficial layers of cartilage caps of MO(a) and extragenetic solitary chondroma(b) (40×).

<p>The chondrocytes with functional EXT1 in MO are less than those in extragenetic solitary chondroma.</p

MMP13 mutations are the cause of recessive metaphyseal dysplasia, Spahr type

Metaphyseal dysplasia, Spahr type (MDST; OMIM 250400) was described in 1961 based on the observation of four children in one family who had rickets-like metaphyseal changes but normal blood chemistry and moderate short stature. Its molecular basis and nosologic status remained unknown. We followed up on those individuals and diagnosed the disorder in an additional member of the family. We used exome sequencing to ascertain the underlying mutation and explored its consequences on three-dimensional models of the affected protein. The MDST phenotype is associated with moderate short stature and knee pain in adults, while extra-skeletal complications are not observed. The sequencing showed that MDST segregated with a c.619T>G single nucleotide transversion in MMP13. The predicted non-conservative amino acid substitution, p. Trp207Gly, disrupts a crucial hydrogen bond in the calcium-binding region of the catalytic domain of the matrix metalloproteinase, MMP13. The MDST phenotype is associated with recessive MMP13 mutations, confirming the importance of this metalloproteinase in the metaphyseal growth plate. Dominant MMP13 mutations have been associated with metaphyseal anadysplasia (OMIM 602111), while a single child homozygous for a MMP13 mutation had been previously diagnosed as "recessive metaphyseal anadysplasia," that we conclude is the same nosologic entity as MDST. Molecular confirmation of MDST allows distinction of it from dominant conditions (e.g., metaphyseal dysplasia, Schmid type; OMIM # 156500) and from more severe multi-system conditions (such as cartilage-hair hypoplasia; OMIM # 250250) and to give precise recurrence risks and prognosis

Characteristics of study subjects in MO family.

<p>Characteristics of study subjects in MO family.</p