Preliminary study of familial nonsyndromic tooth agenesis caused by ectodysplasin A mutation / 口腔疾病防治

Objective@# To explore the pathogenic genes in a Chinese family affected by nonsyndromic tooth agenesis so as to study the pathogenesis of oligodontia.@*Methods @# Hospital ethical approval and informed consent of the patients and family members were obtained. Clinical data of the proband and close family members were collected, peripheral venous blood was collected, and DNA was extracted. Gene sequencing was performed through whole-exome sequencing, and then the screened pathogenic genes were verified by Sanger sequencing. The three-dimensional structure of the mutant proteins was analyzed and compared with the wild-type using bioinformatics tools.@*Results@#The two patients with congenital majority tooth loss in this family were cousins, and there were no other patients with congenital majority tooth loss in the family. Besides congenital multiple tooth loss, the two patients had no obvious hair abnormalities, finger/toe abnormalities, sweating abnormalities or other abnormal manifestations of ectodermal tissue. We found a mutant gene that in this family by carrying out gene sequencing of the patients and their close family members. A novel EDA (ectodysplasin A) missense mutation c.983C>T (p. Pro328Leu) was identified, which changed the encoded amino acid from proline (Pro) to leucine (Leu). Analysis of the mutation site showed that the site was highly conserved, and three-dimensional structure modeling also found that it changed the structure of EDA. @* Conclusion@#A novel EDA missense variant (c.983C>T, p.Pro328Leu) was first identified in a Chinese family with nonsyndromic tooth agenesis, extending the mutation spectrum of the EDA gene.

Clinical and genetic analysis of a child with hyperekplexia / 中华神经科杂志

Objective:To analyze the clinical phenotype and gene sequencing results of a child with hyperekplexia, and to clarify her genetic etiology.Methods:The clinical information of the child was collected, and the whole exome sequencing of the child and her parents was performed. The suspected pathogenic variants were verified by Sanger sequencing and bioinformatics analysis.Results:There was a 12 years old girl, who was hospitalized in the Department of Pediatric Neurology of Linyi People′s Hospital because of "paroxysmal limb stiffness for more than 11 years and aggravated for half a month" on July 4, 2022. The girl showed exaggerated startle reflexes and generalized siffness in response to external sudden, unexpected stimuli, occasionally accompanied by apnea and cyanosis, frequent attacks occurred several times a day, lasting for 1-30 minutes, and early head and abdomen flexion can be relieved. She showed normal growth and development, no abnormality in brain magnetic resonance imaging and video electroencephalogram during seizure. The whole exome sequencing showed that there was a missense heterozygous mutation c.643T>C(p.W215R) in the SLC6A5 gene of the child. Neither of the parents carried this mutation, which was a novel and de novo variant. According to the guidelines of American College of Medical Genetics and Genomics, this variant was a likely pathogenic variant [PS2: de novo (both maternity and paternity confirmed) in the patient with the disease and no family history; PM2: undetected variants in the normal population; PP3: multiple softwares predicted that this mutation would have harmful effects on genes or gene products], and highly conserved. Swiss modeling found that the hydrogen bond of the modified amino acid also changed. Conclusions:Hyperekplexia is relatively rare and prone to misdiagnosis. The main clinical features are excessive startle reflexes (limb shaking, or jumping) to unexpected external stimuli, resulting in overall stiffness, normal growth and development, and normal video electroencephalogram during the seizure. The likely pathogenic heterozygous missense variant c.643T>C (p.W215R) of SLC6A5 gene is the genetic cause of this case.

A case of developmental epileptic encephalopathy type 67 caused by CUX2 gene mutation and literature review / 中华神经科杂志

Objective:To summarize the clinical phenotype and CUX2 gene variation characteristics of developmental epileptic encephalopathy type 67 confirmed by whole exome sequencing. Methods:Clinical data of 1 case diagnosed as CUX2 gene mutations related developmental epileptic encephalopathy type 67 in the Children′s Hospital Affiliated to Zhengzhou University in January 2021 were collected, the patient′s clinical characteristics, genetic testing, head imaging, electroencephalogram results and treatment were summarized, and the patient was regularly followed-up every 3 months. At the same time, the domestic and foreign literatures on epileptic encephalopathy caused by CUX2 gene mutation were reviewed. Results:The proband was a 6 years and 4 months old girl. The main clinical manifestations included focal origin progression to bilateral tonic-clonic seizures, retardation of intellectual, language, and motor development, autistic behavior, hyperactivity disorder, and involuntary hand clapping. The video electroencephalogram showed extensive spiny slow wave and multi-spiny slow wave emission in waking and sleeping stages, and spiny slow wave and spiky slow wave emission in bilateral anterior head in sleeping stage. Brain magnetic resonance imaging (MRI) plain scan and T 2-fluid attenuated inversion recovery (T 2-FLAIR) thin layer scan showed that the signal of the left hippocampus was higher than that of the right, and the left hippocampus was slightly swollen. One month later, the brain MRI and T 2-FLAIR were reexamined. The left hippocampal signal was still slightly higher and decreased, and the hippocampal volume was slightly reduced. Whole exome sequencing showed the CUX2 gene with c.1768G>A(p.Glu590Lys) heterozygous missense variant, which was a reported de novo pathogenic variant and both of her parents were wild-type. A total of 10 cases of new heterozygous missense variants in CUX2 gene [c.1768G>A (p.Gelu590Lys)] were reported in 4 literatures. No relevant cases have been reported in China. Conclusions:Developmental epileptic encephalopathy type 67 is relatively rare. The main clinical features are seizures, global developmental delay, movement disorders, athetosis, autism and hyperactivity disorder. The heterozygous missense variant c.1768G>A (Glu590Lys) of CUX2 gene maybe the genetic cause of this case.

USH2A mutation and specific driver mutation subtypes are associated with clinical efficacy of immune checkpoint inhibitors in lung cancer / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

This study aimed to identify subtypes of genomic variants associated with the efficacy of immune checkpoint inhibitors (ICIs) by conducting systematic literature search in electronic databases up to May 31, 2021. The main outcomes including overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and durable clinical benefit (DCB) were correlated with tumor genomic features. A total of 1546 lung cancer patients with available genomic variation data were included from 14 studies. The Kirsten rat sarcoma viral oncogene homolog G12C (KRASG12C) mutation combined with tumor protein P53 (TP53) mutation revealed the promising efficacy of ICI therapy in these patients. Furthermore, patients with epidermal growth factor receptor (EGFR) classical activating mutations (including EGFRL858R and EGFRΔ19) exhibited worse outcomes to ICIs in OS (adjusted hazard ratio (HR), 1.40; 95% confidence interval (CI), 1.01‍‒‍1.95; P=0.0411) and PFS (adjusted HR, 1.98; 95% CI, 1.49‍‒‍2.63; P<0.0001), while classical activating mutations with EGFRT790M showed no difference compared to classical activating mutations without EGFRT790M in OS (adjusted HR, 0.96; 95% CI, 0.48‍‒‍1.94; P=0.9157) or PFS (adjusted HR, 0.72; 95% CI, 0.39‍‒‍1.35; P=0.3050). Of note, for patients harboring the Usher syndrome type-2A(USH2A) missense mutation, correspondingly better outcomes were observed in OS (adjusted HR, 0.52; 95% CI, 0.32‍‒‍0.82; P=0.0077), PFS (adjusted HR, 0.51; 95% CI, 0.38‍‒‍0.69; P<0.0001), DCB (adjusted odds ratio (OR), 4.74; 95% CI, 2.75‍‒‍8.17; P<0.0001), and ORR (adjusted OR, 3.45; 95% CI, 1.88‍‒‍6.33; P<0.0001). Our findings indicated that, USH2A missense mutations and the KRASG12Cmutation combined with TP53 mutation were associated with better efficacy and survival outcomes, but EGFR classical mutations irrespective of combination with EGFRT790M showed the opposite role in the ICI therapy among lung cancer patients. Our findings might guide the selection of precise targets for effective immunotherapy in the clinic.

Factors influencing neurodevelopmental disorders in children with SCN8A-related early-onset epilepsy: a follow-up study of 21 cases / 中华实用儿科临床杂志

Objective:To explore the influence factors of neurodevelopmental disorders in children with SCN8A-related early-onset epilepsy through analyzing their clinical characteristics and following up their neurodeve-lopmental status. Methods:A retrospective analysis was carried out on 21 children (13 males and 8 females, the age ranged from 4 months to 8 years, average 31.6 months)with SCN8A-related early-onset epilepsy treated in Guangzhou Women and Children′s Medical Center and Kunming Children′s Hospital between January 2017 and February 2021.All patients underwent whole-exome sequencing and Sanger sequencing.The pathogenicity was estimated according to the American College of Medical Genetics and Genomics guidelines.The clinical data of all patients were also collected, including the age of onset of the disease, forms of seizures, seizure frequency, neurological development at onset, electroencephalogram (EEG) and brain magnetic resonance imaging (MRI). Besides, the patients were followed up to acquire the effect of sodium channel blockers after the onset of seizures, the process or improvement of neurodeve-lopment, EEG evaluation and neurodevelopmental outcomes.Patients were grouped based on data analysis results.The Fisher′s exact test was conducted to measure the effect of various factors on the neurodevelopmental process and outcome, and corresponding coe-fficients were calculated. Results:The average onset age of 21 patients was 0-9 months.The follow-up duration was 4 months-8 years.Three cases died.Sixteen cases (76.2%) had early infantile epileptic encephalopathy (EIEE), 5 cases (23.8%) had epilepsy without encephalopathy, and 1 case had benign infantile epilepsy.Fourteen cases (66.7%) belonged to drug resistant epilepsy.Only one child showed normal neurodevelopment.Eleven children showed delayed neurodevelopment, but improvement was observed.Nine children were retrogressed and stagnated in terms of neurodevelopment.Small age at onset ( Fisher=9.517, P=0.020, r=0.571), high seizure frequency ( Fisher=10.512, P=0.003, r=0.572), EEG background ( Fisher=10.512, P=0.003, r=0.572), epileptic discharges ( Fisher=8.288, P=0.008, r=0.542), and EEG changes before and after treatment ( Fisher=10.437, P=0.009, r=0.586) were important factors affecting the neurodevelopmental process.Neurodevelopmental outcome was normal in only 1 case, 1 child belonged to mild mental retardation (MR), 7 children belonged to moderate MR, 3 children belonged to severe MR, and 9 children belonged to profound MR.Statistical analysis indicated that the clinical phenotype ( Fisher=10.059, P=0.004, r=0.739) and drug resistance ( Fisher=13.706, P=0.001, r=0.640) were significantly correlated with neurodevelopmental outcomes.However, the forms of seizures, EEG findings at onset and mutation sites were not related to neurodevelopmental disorders. Conclusions:Most children with SCN8A-related early-onset epilepsy are accompanied with neurodevelopmental retardation of varying degrees.Epileptic encephalopathy and poor response to drug treatment will lead to severe neurodevelopmental disorders.

Homozygous Fukutin Missense Mutation in Two Mexican Siblings with Dilated Cardiomyopathy

ABSTRACT Background: Fukuyama congenital muscular dystrophy (FCMD) is the most common form of a group of autosomal recessive disorders characterized by altered α-dystroglycan glycosylation and caused by FKTN gene mutations. However, mutations of this gene may cause a broad range of phenotypes, including Walker-Warburg syndrome, muscle-brain-eye disease, FCMD, limb-girdle muscular dystrophy without mental retardation, and cardiomyopathy with no or minimal skeletal muscle weakness. Objective: Our purpose was to describe two siblings who died at a young age with dilated cardiomyopathy (DCM), no muscle weakness, or atrophy, and were homozygous for a FKTN missense mutation. Methods: Site-directed next-generation sequencing (NGS) was performed. Pathogenicity of variants of interest was established according to the American College of Medical Genetics (ACMG) criteria, and all available first-degree relatives were screened for mutations by Sanger sequencing. Results: NGS revealed a homozygous FKTN variant in the index case (p.Gly424Ser, rs752358445), classified as likely pathogenic by ACMG criteria. Both parents and an unaffected brother were heterozygous carriers. Since the siblings had no apparent skeletal muscle weakness or central nervous system involvement, FKTN mutations were not initially suspected. Conclusions: This is the first report demonstrating that heterozygous individuals for the FKTN p.Gly424Ser mutation were healthy, while two homozygous brothers suffered severe DCM, strongly suggesting that this FKTN mutation is a rare cause of autosomal recessive DCM.

De novo ALX4 variant detected in child with non-syndromic craniosynostosis

Current understanding of the genetic factors contributing to the etiology of non-syndromic craniosynostosis (NSC) remains scarce. The present work investigated the presence of variants in ALX4, EFNA4, and TWIST1 genes in children with NSC to verify if variants within these genes may contribute to the occurrence of these abnormal phenotypes. A total of 101 children (aged 45.07±40.94 months) with NSC participated in this cross-sectional study. Parents and siblings of the probands were invited to participate. Medical and family history of craniosynostosis were documented. Biological samples were collected to obtain genomic DNA. Coding exons of human TWIST1, ALX4, and EFNA4 genes were amplified by polymerase chain reaction and Sanger sequenced. Five missense variants were identified in ALX4 in children with bilateral coronal, sagittal, and metopic synostosis. A de novo ALX4 variant, c.799G>A: p.Ala267Thr, was identified in a proband with sagittal synostosis. Three missense variants were identified in the EFNA4 gene in children with metopic and sagittal synostosis. A TWIST1 variant occurred in a child with unilateral coronal synostosis. Variants were predicted to be among the 0.1% (TWIST1, c.380C>A: p. Ala127Glu) and 1% (ALX4, c.769C>T: p.Arg257Cys, c.799G>A: p.Ala267Thr, c.929G>A: p.Gly310Asp; EFNA4, c.178C>T: p.His60Tyr, C.283A>G: p.Lys95Glu, c.349C>A: Pro117Thr) most deleterious variants in the human genome. With the exception of ALX4, c.799G>A: p.Ala267Thr, all other variants were present in at least one non-affected family member, suggesting incomplete penetrance. Thus, these variants may contribute to the development of craniosynostosis, and should not be discarded as potential candidate genes in the diagnosis of this condition.

Mutation analysis of SCN4A gene in a family with hypokalemic periodic paralysis / 中国医师杂志

Objective:To analyze the clinical features and SCN4A gentic background of a family with hypokalemic periodic paralysis.Methods:Peripheral blood samples and clinical data were collected from the proband, his brother and parents, and genomic DNA was extracted from these blood samples. Genome-wide exome sequencing was conducted to determine the mutation site in the proband and then allele-specific oligonucleotide primers were designed based on the mutation site. Polymerase chain reaction (PCR) was performed to detect the mutation site to further identify the causative gene in the family.Results:The patient was a 19-years-old male, Han nationality. The patient presented with periodic paralysis while hypokalemia at the same time. His father and grandpa have a similar medical history in the family. A hybrid missense variation (p.R672H) was identified in exon 12 of SCN4A gene in the proband. The same mutation was also detect in the proband's father.Conclusions:The heterozygous missense variation of SCN4A gene (p.R672H) found in this study resulted in familial hypokalemic periodic paralysis. Our research provided reference for the future genetic counseling of this patient and enriched the research data on the relationship between genotype and clinical manifestations.

Genetic study on a consanguineous Chinese family with premature ovarian insufficiency caused by a missense mutation of PSMC3IP gene / 中国医师杂志

Objective:To explore the genetic etiology for a premature ovarian insufficiency (POI) patient from a consanguineous Chinese family, and to provide basis for genetic counseling and fertility counseling.Methods:Whole-exome sequencing was performed using DNA extracted from the blood sample of POI patient. Suspected pathogenic mutation was analyzed by bioinformatics methods and verified by Sanger sequencing. The pathogenicity of the variation was assessed according to the ACMG genetic variation classification criteria and guidelines.Results:A homozygous variation, c. 32G>T (p.G11V), of PSMC3IP was identified in the patient. Bioinformatics analysis revealed that the variation was conserved in different animal species, and this variation was classified as possible pathogenic variation according to the ACMG genetic variation classification criteria and guidelines.Conclusions:The homozygous missense variation of PSMC3IP is the cause of the POI patient in this family. We are reporting for the first time the missense variation in PSMC3IP gene caused POI, which enriched the mutation spectrum of PSMC3IP and provided the basis for genetic counseling and fertility guidance of this family.

Novel compound heterozygous mutation in NPC1 gene cause Niemann–Pick disease type C with juvenile onset

Niemann–Pick disease type C (NPC) is a progressive lysosomal storage disorder caused by mutations in the NPC1 (in 95% of cases) or NPC2 (in *5% of cases) genes, inherited in an autosomal recessive manner. We report the case of a 38-year-old woman with learning disorder from her first year of schooling, and could notice slow progressed cognitive impairment, social withdrawal, apathy, handwriting alterations, deterioration of language skills and dysphagia. Brain magnetic resonance imaging showed severe cerebellar atrophy, hypoplasia of the corpus callosum, asymmetric lateral ventricular enlargement, and severe enlargement of frontal and parietal subarachnoid spaces. Next generation sequencing for NPC genes (NPC1 and NPC2) detected compound heterozygous mutations in NPC1 gene, including c.1553G [A (p.Arg518Gln), paternally inherited, and c.1270C [ T (p.Pro424Ser) maternally inherited. The first mutation has been already described in literature and correlated to NPC, while the second mutation is still unknown. Moreover, filipin test and quantification of plasma oxysterols confirmed NPC diagnosis. We can suggest the missense mutation c.1270C [ T (p.Pro424Ser) as a new causative mutation of NPC

ARHGEF16 variants screening and mutation function analysis for children with total anomalous pulmonary venous connection / 上海交通大学学报（医学版）

Objective:To investigate the pathogenesis of total anomalous pulmonary venous connection (TAPVC), and to identify ARHGEF16 gene through full exon sequencing screening and analyze its mutation function. Methods:The blood, clinical data and auxiliary examination results of 78 children with TAPVC and 100 healthy controls were collected, and the genomic DNA was extracted for ARHGEF16 mutation screening. ARHGEF16 wild-type and mutant expression plasmids were constructed and transfected into 293T cells. mRNA and protein expression levels were detected by quantitative real-time PCR (RT-qPCR) and Western blotting, respectively. Protein-protein interaction exploration was performed by Cytoscape software. Results:Two novel variants c.C236>T (A79V) and c.G619>C (G207R) were found in TAPVC patients and were not found in healthy controls. Compared with the wild type, the mutants ARHGEF16 were up-regulated in both mRNA and protein expression levels. Protein interaction analysis showed that ARHGEF16 and RAC1 were directly associated; RAC1 expression was up-regulated in HEK293 cells with ARHGEF16 overexpression through RT-qPCR. Conclusion:The missense mutations of ARHGEF16 affect the mRNA and protein expression levels of ARHGEF16. Overexpression of ARHGEF16 up-regulates the expression of RAC1, suggesting that it may participate in the development and formation of TAPVC by regulating RAC1.

Class III Malocclusion: Missense Mutations in DUSP6 Gene

Objective: To determine the DUSP6 gene mutation in three generations of Malaysian Malay subjects having Class III malocclusion. Material and Methods: Genetic analyses of DUSP6 gene were carried out in 30 subjects by selecting three individuals representing three generations, respectively, from ten Malaysian Malay families having Class III malocclusion and 30 healthy controls. They were submitted Clinical Evaluation to clinical examination, lateral cephalometric radiographs, dental casts, and/ or facial and intra-oral photographs. Buccal cell was taken from each participant of Class III malocclusion and control groups. DNA extractions from buccal cell were carried out using Gentra puregene buccal cell kit. Bio Edit Sequence Alignment Editor software was used to see the sequencing result. Results: A heterozygous missense mutation c.1094C>T (p. Thr 365 Ile) was identified in DUSP6 gene in three members of one family with Class III malocclusion, whereas no mutation was found in the control group. Conclusion: Current study successfully identified a missense mutation in DUSP6 gene among one Malaysian Malay family affected by Class III malocclusion. The outcome of this study broadened the mutation spectrum of Class III malocclusion and the importance of DUSP6 gene in skeletal functions.

Genetic study of a pedigree affected with oculodentodigital dysplasia / 中华医学遗传学杂志

Objective@#To explore the genetic basis of a pedigree affected with oculodentodigital dysplasia.@*Methods@#Genomic DNA was extracted from peripheral blood or amniotic fluid samples derived from the pedigree. Exon 2 of the GJA1 gene was amplified for sequencing.@*Results@#Two pedigree members were found to carry heterozygous missense variation of the GJA1 gene, c. 221A>C (p.H74P).@*Conclusion@#The missense c. 221A>C variation of the GJA1 gene probably underlies the oculodentodigital dysplasia in this pedigree.

Screening of pathogenic mutation in a Chinese family with congenital pulverulent cataract / 中华实验眼科杂志

Objective@#To analysis the pathogenic mutation and the clinical characteristics of a three generation family with congenital pulverulent cataract.@*Methods@#A congenital cataract family was chosen from the First Affiliated Hospital of AnHui Medical University, 5 ml peripheral blood was obtained from each family member to extract genomic DNA.Next generation sequencing was used to detect the mutation in proband (Ⅱ5), Ⅱ6 and Ⅲ8, and Sanger sequencing was applied to verify pathogenic mutation in the whole family members.The mutation site was compared with the gene sequence of 10 000 normal Chinese.PolyPhen-2 and SIFT were applied to analysis the alteration on the protein structure and function and its possible pathogenesis.This study followed the Declaration of Helsinki and was approved by the Ethics Committee of AnHui Medical University (NO.PJ2017-5-17). All patients signed informed consent.@*Results@#The pedigree consisted of 19 members of three generations, including 10 patients and 9 normal family members.Heterozygous mutation of GJA3 gene c. 427G>A (p.G143R) was detected in all patients of the pedigree, but was not found in normal members of the pedigree and 10 000 normal Chinese.The score calculated from SIFT and PolyPhen-2 indicated that the mutation probably had malignant effect on normal protein structure, Swiss-model website analysis showed that the mutation likely altered the secondary structure of the protein CX 46 by reducing an α-helix between 107-115 amino acids.Meanwhile, c.1325-1G>T mutation of HSF4 gene were detected in Ⅱ5 and Ⅲ8, which was not found in other family members and 10 000 normal Chinese.HSF and MaxEntScan results showed that the mutation probably had serious effect on the splicing of mRNA.The cataract development rates of Ⅱ5 and Ⅲ8 were faster than that of the same age in the same generation of the pedigree, and the morphology of lens opacity was changed.@*Conclusions@#The heterozygous c. 427G>A mutation in GJA3 gene is responsible for pulverulent cataract in this family, meanwhile the c. 1325-1G>T mutation in HSF4 gene may change the type of phacoscotasmus and accelerate the progress of disease.

Mutations analysis of FRMD7 gene in idiopathic congenital nystagmus families / 中华实验眼科杂志

Objective@#To reveal the pathogenic mutations in Chinese families with idiopathic congenital nystagmus(ICN)@*Methods@#Six families with ICN were recruited from Subei People's Hospital.DNA was extracted from peripheral blood samples of all participants.All coding and exon-intronic boundary regions of the targeted gene FRMD7 were amplified with PCR and sequenced using Sanger sequencing to detect potential pathogenic mutations.This study followed the Helsinki Declaration and was approved by the Ethics Committee of Subei People's Hospital (NO.2015KY-126). All patients or their guardians signed informed consent.@*Results@#Three mutations (c.902A>G, c.1944T>A and 1945G>T) were screened in two families after co-segregation validation of intrafamilial genotype-phenotype, c.1944T>A and 1945G>T were newly detected mutations which were not detected in 100 normal controls.No significant mutations were found in the FRMD7 coding region and adjacent splicing sites in the probands of the other four families.@*Conclusions@#Two novel pathogenic mutations of FRMD7 are discovered, which expands the pathogenic mutational spectrum of FRMD7 gene causing ICN.

Screening of pathogenic mutation in a Chinese family with congenital pulverulent cataract / 中华实验眼科杂志

Objective To analysis the pathogenic mutation and the clinical characteristics of a three generation family with congenital pulverulent cataract. Methods A congenital cataract family was chosen from the First Affiliated Hospital of AnHui Medical University,5 ml peripheral blood was obtained from each family member to extract genomic DNA. Next generation sequencing was used to detect the mutation in proband (Ⅱ5),Ⅱ6 and Ⅲ8, and Sanger sequencing was applied to verify pathogenic mutation in the whole family members. The mutation site was compared with the gene sequence of 10000 normal Chinese. PolyPhen-2 and SIFT were applied to analysis the alteration on the protein structure and function and its possible pathogenesis. This study followed the Declaration of Helsinki and was approved by the Ethics Committee of AnHui Medical University ( NO. PJ2017-5-17 ) . All patients signed informed consent. Results The pedigree consisted of 19 members of three generations,including 10 patients and 9 normal family members. Heterozygous mutation of GJA3 gene c. 427G>A ( p. G143R) was detected in all patients of the pedigree,but was not found in normal members of the pedigree and 10000 normal Chinese. The score calculated from SIFT and PolyPhen-2 indicated that the mutation probably had malignant effect on normal protein structure,Swiss-model website analysis showed that the mutation likely altered the secondary structure of the protein CX 46 by reducing anα-helix between 107-115 amino acids. Meanwhile,c. 1325-1G>T mutation of HSF4 gene were detected in Ⅱ5 and Ⅲ8, which was not found in other family members and 10000 normal Chinese. HSF and MaxEntScan results showed that the mutation probably had serious effect on the splicing of mRNA. The cataract development rates of Ⅱ5 andⅢ8 were faster than that of the same age in the same generation of the pedigree,and the morphology of lens opacity was changed. Conclusions The heterozygous c. 427G>A mutation in GJA3 gene is responsible for pulverulent cataract in this family,meanwhile the c. 1325-1G>T mutation in HSF4 gene may change the type of phacoscotasmus and accelerate the progress of disease.

Mutations analysis of FRMD7 gene in idiopathic congenital nystagmus families / 中华实验眼科杂志

Objective To reveal the pathogenic mutations in Chinese families with idiopathic congenital nystagmus(ICN) Methods Six families with ICN were recruited from Subei People's Hospital. DNA was extracted from peripheral blood samples of all participants. All coding and exon-intronic boundary regions of the targeted gene FRMD7 were amplified with PCR and sequenced using Sanger sequencing to detect potential pathogenic mutations. This study followed the Helsinki Declaration and was approved by the Ethics Committee of Subei People's Hospital (NO. 2015KY-126). All patients or their guardians signed informed consent. Results Three mutations (c. 902A>G, c. 1944T>A and 1945G>T) were screened in two families after co-segregation validation of intrafamilial genotype-phenotype,c. 1944T>A and 1945G>T were newly detected mutations which were not detected in 100 normal controls. No significant mutations were found in the FRMD7 coding region and adjacent splicing sites in the probands of the other four families. Conclusions Two novel pathogenic mutations of FRMD7 are discovered,which expands the pathogenic mutational spectrum of FRMD7 gene causing ICN.

Pedigree study of hereditary small cerebral vascular disease caused by c.821G＞A heterozygous mutation of HtrA serine protease-1 gene / 中华神经科杂志

Objective To investigate the clinical manifestations,imaging features,molecular genetic characteristics and possible pathogenic mechanisms of hereditary cerebral small vessel disease (CSVD) caused by heterozygous mutation of HtrA serine protease-1 (HTRA1) gene.Methods The clinical data of a Chinese Han family with CSVD carrying a heterozygous mutation of HTRA 1 gene,which came from the Department of Neurology,Henan Provincial People's Hospital in March 2018,were analyzed retrospectively.The clinical and radiographic features were summarized.Several high-throughput whole exon high-throughput sequencing was used to capture the mutation sites and the Sanger sequencing was used to validate the results.The family diagram was drawn and the 3D model construction and mutation function prediction were performed using silico tools.The relevant literature was reviewed and the pathogenesis was explored.Results The pedigree map showed that the family had an autosomal dominant inheritance pattern.Three generations of the family were investigated,and three family members in the same generation suffered from the disease.The first symptom of the proband was diplopia at the age of 39,accompanied by recurrent stroke,cognitive impairment and mood disorders,without alopecia.Head magnetic resonance imaging revealed bilateral diffuse,symmetric lesions,multiple lacunar infarcts,perivascular space,and microbleeds.The elder sister of the proband developed symptoms of left limb weakness at the age of 46,whose other clinical and imaging features were similar to those of the proband.The proband's mother died at the age of 59 due to repeated strokes.Whole exon sequencing indicated heterozygous missense mutation at c.821G＞A locus of HTRA1 gene in the proband and her 4th elder sibling,which was a new pathogenic mutation after consulting several mutation sites of databases.Function prediction suggested pathogenicity.Conclusions The heterozygous mutation of c.821G＞A in HTRA1 gene may lead to autosomal dominant CVSD.This genetic type should be given clinical attention.

Hallazgo de una nueva mutación en una familia chilena con diabetes monogénica: caso clínico / Finding of a new mutation in a Chilean family with monogenic diabetes: report of one case

We report a 21 years old woman, without offspring, with diabetes mellitus diagnosed at 17 years of age, without ketosis or weight loss. Her body mass index was 18 kg/m2. Her C peptide was normal (2.3 ng/ml) and diabetes mellitus type 1 autoantibodies were negative. A monogenic diabetes Maturity Onset Diabetes of the Young (MODY) was proposed. Her family study disclosed a diabetic father and a brother with altered fasting glucose levels. The University of Exeter score for MODY yielded a 75.5% probability of MODY2. In the genetic-molecular study of the glucokinase gene (MODY2), the patient had a mutation at position 1343 of exon 10, corresponding to a heterozygous substitution of guanine by adenine (1343 G >A). The same mutation was found in her father and brother. This mutation is different from those previously described in the literature. The described change determines that a glycine is replaced by aspartic at amino acid 448 of the enzyme (non-synonymous substitution). The diagnosis of MODY2 was therefore confirmed in the patient and her father. The mutation was inherited by paternal line.

A De Novo RAPGEF2 Variant Identified in a Sporadic Amyotrophic Lateral Sclerosis Patient Impairs Microtubule Stability and Axonal Mitochondria Distribution

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that is frequently linked to microtubule abnormalities and mitochondrial trafficking defects. Whole exome sequencing (WES) of patient-parent trios has proven to be an efficient strategy for identifying rare de novo genetic variants responsible for sporadic ALS (sALS). Using a trio-WES approach, we identified a de novo RAPGEF2 variant (c.4069G>A, p.E1357K) in a patient with early-onset sALS. To assess the pathogenic effects of this variant, we have used patient-derived skin fibroblasts and motor neuron-specific overexpression of the RAPGEF2-E1357K mutant protein in Drosophila. Patient fibroblasts display reduced microtubule stability and defective microtubule network morphology. The intracellular distribution, ultrastructure, and function of mitochondria are also impaired in patient cells. Overexpression of the RAPGEF2 mutant in Drosophila motor neurons reduces the stability of axonal microtubules and disrupts the distribution of mitochondria to distal axons and neuromuscular junction (NMJ) synapses. We also show that the recruitment of the pro-apoptotic protein BCL2-associated X (BAX) to mitochondria is significantly increased in patient fibroblasts compared with control cells. Finally, increasing microtubule stability through pharmacological inhibition of histone deacetylase 6 (HDAC6) rescues defects in the intracellular distribution of mitochondria and BAX. Overall, our data suggest that the RAPGEF2 variant identified in this study can drive ALS-related pathogenic effects through microtubule dysregulation.