A novel splice site mutation of CRYBA3/A 1 gene associated with congenital cataract in a Chinese family

AIM： To identify the disease-causing mutation responsible for the presence of congenital cataract in a Chinese family. METHODS： The study recruited a four-generation Chinese pedigree affected by autosomal dominant congenital cataract （ADCC）. Family history and the history of cataract extraction were recorded. Blood samples were collected from individuals for DNA extraction. Direct sequencing of congenital cataract-associated genes was performed. Single-strand conformational polymorphism and bioinformatic analysis were conducted to further study the mutation. RESULTS： Direct sequencing revealed a novel splice site mutation of c.30-2 A〉G in the CRYBA3/A1 gene. The mutation co-segregated within all affected individuals in the family and was not found in unaffected members or 100 unrelated normal controls. These results were further confirmed by single-strand conformational polymorphism and bioinformatic analysis using the Human Splicing Finder and MaxEnt online software and Annovar computer software. CONCLUSION： c,30-2 A〉G mutation of CRYBA3/A1 gene is a novel mutation and broadens the genetic spectrum of ADCC, KEYWORDS： splice site mutation; congenital cataract; CRYBA3/A1 gene

Phylogenetic and epidemiological characteristics of H9N2 avian influenza viruses in Shandong Province, China from 2019 to 2021

H9N2 avian influenza virus(AIV) has widely circulated in poultry worldwide and sporadic infections in humans and mammals. During our surveillance of chicken from 2019 to 2021 in Shandong Province, China, we isolated 11 H9N2AIVs. Phylogenetic analyses showed that the eight gene segments of the 11 isolates were closely related to several sublineages of Eurasian lineage: BJ/94-like clades(HA and NA genes), G1-like clades(PB2 and M genes), and SH/F/98-like clades(PB1, PA, NP and NS genes). The isolates showed mutation sites that preferentially bind to humanlike receptors(HA) and mammalian fitness sites(PB2, PB1 and PA), as well as mutations in antigen and drug resistance sites. Moreover, studies with mice revealed four isolates with varying levels of pathogenicity. The average antibody titer of the H9N2 AIVs was 8.60 log2. Based on our results, the epidemiological surveillance of H9N2 AIVs should be strengthened.

Rapid Detection of rpoB Gene Mutations in Rif-resistant M.tuberculosis Isolates by Oligonucleotide Microarray

Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DNA of M. tuberculosis was amplified by PCR, hybridized and scanned. Direct sequencing was performed to verify the results of oligonucleotide microarray Results Of the 102 rifampin-resistant strains 98 （96.1%） had mutations in the rpoB genes. Conclusion Oligonucleotide microarray with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of rifampin resistance in M. tuberculosis isolates.

Bilateral papilledema caused by chronic infantile neurological cutaneous and articular syndrome in a child with a novel (p. D305N) mutation in NLRP3 gene: a case report

The rare disease of chronic infantile neurological cutaneous and articular(CINCA)syndrome,is caused by the over-secretion of interleukin(IL)-1βdue to a gain-of-function NLRP3 gene mutation in the autosomal chromosome which often involves in eyes.In this report,we studied a 9-year-old girl with CINCA.The eyes were also involved and presented bilateral papilledema.Genetic testing revealed that the symptoms were caused by a novel gene mutation site(c.913G>A,p.D305N)in conservative domain exon-3 of NLRP3 which is gain-function gene of CINCA.The patient had the characteristic facial features,frontal fossa and saddle nose,manifested the generalized urticaria-like skin rash at two weeks after birth,periodic fever 6 months after birth,sensorineural deafness at 7 years old,and bilateral papilledema,aseptic meningitis and knee arthropathy at 9 years old.White cell counts,C-reactive protein increased and intracranial pressure raised to 300 mmH2O.The meningeal thickening enhanced by gadolinium in magnetic resonance imaging(MRI).Based on clinical features and genetic test,the girl was diagnosed bilateral papilledema secondary to CINCA and administered prednisone and lowered intracranial pressure medicine to resolve symptoms.With 3-year follow-up,patient had no inflammatory flare-up with visual acuity improvement.The finding of novel genetic mutation site(p.D305N)in NLRP3 gene expanded genotype spectrum associated with CINCA.This case also expanded the cause spectrum of papilledema and it highlighted systemic disease history for patients with bilateral papilledema.

A novel splice mutation of HERG in a Chinese family with long QT syndrome

Congenital long QT syndrome (LQTS) is a genetically heterogeneous disease in which six ion-channel genes have been identified. The phenotype-genotype relationships of the HERG (human ether-a-go-go-related gene) mutations are not fully understood. The objective of this study is to identify the underlying genetic basis of a Chinese family with LQTS and to characterize the clinical manifestations properties of the mutation. Single strand conformation polymorphism (SSCP) analyses were conducted on DNA fragments amplified by polymerase chain reaction from five LQT-related genes. Aberrant conformers were analyzed by DNA sequencing. A novel splice mutation in C-terminus of HERG was identified in this Chinese LQTS family,leading to the deletion of 11-bp at the acceptor splice site of Exon9 [Exon9 IVS del (-12→-2)]. The mutation might affect,through deficient splicing, the putative cyclic nucleotide binding domain (CNBD) of the HERG K+ channel. This mutation resulted in a mildly affected phenotype. Only the proband had a history of syncopes, while the other three individuals with long QT interval had no symptoms. Two other mutation carriers displayed normal phenotype. No sudden death occurred in the family. The 4 affected individuals and the two silent mutation carriers were all heterozygous for the mutation. It is the first splice mutation of HERG reported in Chinese LQTS families. Clinical data suggest that the CNBD mutation may be less malignant than mutations occurring in the pore region and be partially dominant over wild-type function.

Small Ubiquitin-Like Modifier Conjugating Enzyme with Active Site Mutation Acts as Dominant Negative Inhibitor of SUMO Conjugation in Arabidopsis

Small ubiquitin-like modifier （SUMO） conjugation affects a broad range of processes in plants, including growth, flower initiation, pathogen defense, and responses to abiotic stress. Here, we investigate in vivo and in vitro a SUMO conjugating enzyme with a Cys to Ser change in the active site, and show that it has a dominant negative effect. In planta expression significantly perturbs normal development, leading to growth retardation, early flowering and gene expression changes. We suggest that the mutant protein can serve as a probe to investigate sumoylation, also in plants for which poor genetic infrastructure precludes analysis via loss-of-function mutants.

Comprehensive genetic diagnosis of patients with Duchenne/Becker muscular dystrophy(DMD/BMD) and pathogenicity analysis of splice site variants in the DMD gene

Duchenne muscular dystrophy(DMD)and Becker muscular dystrophy(BMD)are caused by mutations in the DMD gene.The aim of this study is to identify pathogenic DMD variants in probands and reduce the risk of recurrence of the disease in affected families.Variations in 100 unrelated DMD/BMD patients were detected by multiplex ligation-dependent probe amplification(MLPA)and next-generation sequencing(NGS).Pathogenic variants in DMD were successfully identified in all cases,and 11 of them were novel.The most common mutations were intragenic deletions(69%),with two hotspots located in the 5'end(exons 2–19)and the central of the DMD gene(exons 45–55),while point mutations were observed in 22%patients.Further,c.1149+1G>A and c.1150?2A>G were confirmed by hybrid minigene splicing assay(HMSA).This two splice site mutations would lead to two aberrant DMD isoforms which give rise to severely truncated protein.Therefore,the clinical use of MLPA,NGS,and HMSA is an effective strategy to identify variants.Importantly,eight embryos were terminated pregnancies according to prenatal diagnosis and a healthy boy was successfully delivered by preimplantation genetic diagnosis(PGD).Early and accurate genetic diagnosis is essential for prenatal diagnosis/PGD to reduce the risk of recurrence of DMD in affected families.

Frequencies and mechanisms of pesticide resistance in Tetranychus urticae field populations in China

The two-spotted spider mite Tetranychus urticate is an important agricultural pest worldwide.It is extremely polyphagous and has developed resistance to many pesticides.Here,we assessed the pesticide resistance of seven field populations of T.urticae in China,their target site mutations and the activities of their detoxification enzymes.The results showed that abamectin and the traditional pesticides pyridaben,profenofos and bifenthrin had higher resistance or lower toxicity than more recently developed pesticides including chlorfenapyr,spinetoram,cyflumetofen,cyenopyrafen,bifenazate and B-azolemiteacrylic.The frequency of point mutations related to abamectin resistance,G314D in the glutamate-gated chloride channel 1(GluCl1)and G326E in GluC13,ranged 47%-70%and 0%-97%,respectively.The frequency of point mutations in A1215D and F1538I of the voltage-gated sodium channel gene(VGSC),which may increase resistance to pyrethroids,ranged 88%-100%and 10%-100%,respectively.For target sites related to organophosphate resistance,mutation frequencies ranged 25%-92%for G119S and 0%-23%for A201S in the acetycholinesterase gene(Ace).Mutation G126S in the bifenazate resistance-related cytochrome b gene(Cytb)was observed in three of the seven T.urticae populations.Higher activities of detoxification enzymes(P450,GST,CarEs and UGTs)were observed in two T.urticae populations,with significant difference in the XY-SX population.These results provide useful information on the status of pesticide resistance of T.urticae in China and suggest that T.urticae field populations may have multiple resistance mechanisms.