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1.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 833-837, 2021 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-34487524

RESUMO

OBJECTIVE: To analyze gene variants in a Chinese pedigree with oculocutaneous albinism (OCA). METHODS: Gene sequencing of the proband and his parents was performed using chip capture high-throughput sequencing and Sanger sequencing techniques, and PolyPhen-2, SIFT, MutationTaster, and FATHMM software were used to predict the function of new variants. At the same time,the pedigree and variant genes of 4 albinism patients from this pedigree were analyzed. RESULTS: Sequencing results showed that the proband's TYR gene (NM_000372) has c.230G>A (p.Arg77Gln) and c.120_121insG (p.Asp42GlyfsTer35) compound heterozygous variants. The proband's father carries c.230G>A heterozygous variant, and the mother carries c.120_121insG heterozygous variant, indicating that the proband's two variants are from his father and mother. The former is a known missense variant, which can cause abnormal or loss of the original function of the protein polypeptide chain. The latter c.120_121insG(p.Asp42GlyfsTer35) is an unreported frameshift variant of the TYR gene subregion (EX1; CDS1). PolyPhen-2, SIFT, MutationTaster and FATHMM predictions are all prompted as "harmful variants". This variant caused the amino acid encoded protein to terminate prematurely, producing a truncated protein, which eventually formed a 76-amino acid short-type TYR protein instead of the 529-amino acid wild-type TYR protein. Through the pedigree analysis, the four patients in the pedigree are all of the same type of compound heterozygous variants, and the disease-causing genes are all from the patient's parents. They belong to a special form of consanguineous marriage within 5 generations. CONCLUSION: The compound heterozygous variants of c.230G>A (p.Arg77Gln) and c.120_121insG (p.Asp42GlyfsTer35) of the TYR gene may underlie the disease in this pedigree. The gene sequencing results enrich the variant spectrum of the TYR gene, and has facilitated molecular diagnosis for the patient.


Assuntos
Albinismo Oculocutâneo , Albinismo Oculocutâneo/genética , Consanguinidade , Heterozigoto , Humanos , Mutação , Linhagem
2.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 838-840, 2021 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-34487525

RESUMO

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with resistance to thyroid hormone syndrome (RTH). METHODS: Exons 7 to 10 of the THRbeta gene were sequenced for the proband and members of his pedigree. RESULTS: Three patients from the pedigree were identified. All have presented with palpitation, fatigue, goiter, elevated free thyroid hormone and free triiodothyronine, and normal or elevated thyrotropin. Genetic testing revealed that the proband, his mother, second sister and one of her daughters had carried a heterozygous c.1336T>A variant of the THRbeta gene, which resulted in substitution of Cysteine by Serine at position 446. The variant was unreported previously. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.1336T>A(p.Cys446Ser) variant of THRbeta gene was predicted to be lilely pathogenic(PM1+PM2+PM5+PP3). CONCLUSION: The c.1336T>A variant, identified in the exon 10 of the THRbeta gene, probably underlay the RTH in this pedigree. Genetic testing has validated the clinical diagnosis for this pedigree.


Assuntos
Genômica , Mães , Feminino , Heterozigoto , Humanos , Mutação , Linhagem
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 884-886, 2021 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-34487537

RESUMO

OBJECTIVE: To explore the genetic basis for a pedigree affected with familial adenomatous polyposis (FAP). METHODS: The proband, with recurrence of blood in the stool, was diagnosed with FAP by endoscopy, pathological examination and a family history. She was subjected to next generation sequencing to detect genetic variant. Suspected variant was verified by Sanger sequencing of members from her pedigree. RESULTS: The proband, her mother and brother were found to carry a heterozygous c.532-1G>A variant of the APC gene, which may lead to aberrant splicing of mRNA resulting in a truncated protein, which may lose its normal function and promote the tumorigenesis. Based on the American College of Medical Genetics and Genomics standards and guidelines, c.532-1G>A variant of APC gene was predicted to be pathogenic(PVS1+PP1+PP4+PP5). CONCLUSION: The c.532-1G>A variant of the APC gene probably underlay the pathogenesis of FAP in this pedigree.


Assuntos
Polipose Adenomatosa do Colo , Genes APC , Polipose Adenomatosa do Colo/genética , Proteína da Polipose Adenomatosa do Colo/genética , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia , Linhagem
4.
BMC Pediatr ; 21(1): 384, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479510

RESUMO

BACKGROUND: The Raynaud-Claes type of X-linked syndromic mental retardation (MRXSRC) is a very rare condition, by intellectual disability ranged from borderline to profound, impaired language development, brain abnormalities, facial dysmorphisms and seizures. MRXSRC is caused by variants in CLCN4 which encodes the 2Cl-/H+ exchanger ClC-4 prominently expressed in brain. CASE PRESENTATION: We present a 3-year-old Chinese girl with intellectual disability, dysmorphic features, brain abnormalities, significant language impairment and autistic features. Brain magnetic resonance imaging (MRI) showed a thin corpus callosum, a mega cisterna magna and ventriculomegaly. Whole exome sequencing (WES) was performed to detect the molecular basis of the disease. It was confirmed that this girl carried a novel heterozygous missense variant (c.1343C > T, p.Ala448Val) of CLCN4 gene, inherited from her mother. This variant has not been registered in public databases and was predicted to be pathogenic by multiple in silico prediction tools. CONCLUSION: Our investigation expands the phenotype spectrum for CLCN4 variants with syndromic X-linked intellectual disability, which help to improve the understanding of CLCN4-related intellectual disability and will help in genetic counselling for this family.


Assuntos
Deficiência Intelectual , Retardo Mental Ligado ao Cromossomo X , Pré-Escolar , China , Canais de Cloreto/genética , Feminino , Genes Ligados ao Cromossomo X , Humanos , Deficiência Intelectual/genética , Retardo Mental Ligado ao Cromossomo X/genética , Mutação , Linhagem , Fenótipo , Sequenciamento Completo do Exoma
5.
Vestn Oftalmol ; 137(4): 123-127, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34410067

RESUMO

Juvenile open-angle glaucoma is a disease with complex pathogenesis affecting young people of working age that can lead to disability. The article describes modern concepts of diagnosis, classification and approaches to the treatment of juvenile glaucoma with special attention paid to the differential diagnostic criteria of juvenile open-angle glaucoma and congenital glaucoma.


Assuntos
Glaucoma de Ângulo Aberto , Adolescente , Proteínas do Citoesqueleto/genética , Proteínas do Olho , Glaucoma de Ângulo Aberto/diagnóstico , Glaucoma de Ângulo Aberto/terapia , Glicoproteínas/genética , Humanos , Mutação , Linhagem
6.
F1000Res ; 10: 361, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34394914

RESUMO

Dopa-responsive dystonia (DRD), also known as Segawa syndrome, is a phenotypically and genetically heterogeneous group of neurological disorders that typically presents as early-onset lower limb dystonia with diurnal fluctuation, and exhibits a marked, persistent response to levodopa. Heterozygous loss-of-function mutations in the guanosine triphosphate cyclohydrolase 1 (GCH1) are the most common cause of DRD. In addition to the classic form of the disease, there have been a number of studies addressing atypical clinical features of GCH1 related DRD with variable age of onset. This report describes a 37-year-old Japanese male patient with a 10-year history of focal upper limb dystonia that initially emerged as task-specific, guitarist's cramp. The dystonic symptoms responded very well to levodopa treatment, and genetic analysis identified a novel heterozygous mutation in the C-terminal catalytic domain of GCH1. Insufficient recognition of this treatable condition often leads to misdiagnosis, which causes delays in the patient receiving adequate dopamine replenishing therapy. A diagnostic trial with levodopa should be considered in all patients with relatively young-onset dystonia, whether they have classic features of DRD or not.


Assuntos
Distúrbios Distônicos , Cãibra Muscular , Adulto , Distúrbios Distônicos/tratamento farmacológico , Distúrbios Distônicos/genética , Humanos , Masculino , Mutação , Linhagem
7.
Sci Immunol ; 6(62)2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413140

RESUMO

Autosomal inborn errors of type I IFN immunity and autoantibodies against these cytokines underlie at least 10% of critical COVID-19 pneumonia cases. We report very rare, biochemically deleterious X-linked TLR7 variants in 16 unrelated male individuals aged 7 to 71 years (mean: 36.7 years) from a cohort of 1,202 male patients aged 0.5 to 99 years (mean: 52.9 years) with unexplained critical COVID-19 pneumonia. None of the 331 asymptomatically or mildly infected male individuals aged 1.3 to 102 years (mean: 38.7 years) tested carry such TLR7 variants (p = 3.5 × 10-5). The phenotypes of five hemizygous relatives of index cases infected with SARS-CoV-2 include asymptomatic or mild infection (n=2, 5 and 38 years), or moderate (n=1, 5 years), severe (n=1, 27 years), or critical (n=1, 29 years) pneumonia. Two boys (aged 7 and 12 years) from a cohort of 262 male patients with severe COVID-19 pneumonia (mean: 51.0 years) are hemizygous for a deleterious TLR7 variant. The cumulative allele frequency for deleterious TLR7 variants in the male general population is < 6.5x10-4 We also show that blood B cell lines and myeloid cell subsets from the patients do not respond to TLR7 stimulation, a phenotype rescued by wild-type TLR7 The patients' blood plasmacytoid dendritic cells (pDCs) produce low levels of type I IFNs in response to SARS-CoV-2. Overall, X-linked recessive TLR7 deficiency is a highly penetrant genetic etiology of critical COVID-19 pneumonia, in about 1.8% of male patients below the age of 60 years. Human TLR7 and pDCs are essential for protective type I IFN immunity against SARS-CoV-2 in the respiratory tract.


Assuntos
COVID-19/complicações , Doenças Genéticas Ligadas ao Cromossomo X/complicações , Doenças do Sistema Imunitário/complicações , Receptor 7 Toll-Like/deficiência , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Criança , Pré-Escolar , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Linhagem , Penetrância , Receptor 7 Toll-Like/genética , Adulto Jovem
8.
J Anim Sci ; 99(8)2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34343280

RESUMO

It is of interest to evaluate crossbred pigs for hot carcass weight (HCW) and birth weight (BW); however, obtaining a HCW record is dependent on livability (LIV) and retained tag (RT). The purpose of this study is to analyze how HCW evaluations are affected when herd removal and missing identification are included in the model and examine if accounting for the reasons for missing traits improves the accuracy of predicting breeding values. Pedigree information was available for 1,965,077 purebred and crossbred animals. Records for 503,716 commercial three-way crossbred terminal animals from 2014 to 2019 were provided by Smithfield Premium Genetics. Two pedigree-based models were compared; model 1 (M1) was a threshold-linear model with all four traits (BW, HCW, RT, and LIV), and model 2 (M2) was a linear model including only BW and HCW. The fixed effects used in the model were contemporary group, sex, age at harvest (for HCW only), and dam parity. The random effects included direct additive genetic and random litter effects. Accuracy, dispersion, bias, and Pearson correlations were estimated using the linear regression method. The heritabilities were 0.11, 0.07, 0.02, and 0.04 for BW, HCW, RT, and LIV, respectively, with standard errors less than 0.01. No difference was observed in heritabilities or accuracies for BW and HCW between M1 and M2. Accuracies were 0.33, 0.37, 0.19, and 0.23 for BW, HCW, RT, and LIV, respectively. The genetic correlation between BW and RT was 0.34 ± 0.03, and between BW and LIV was 0.56 ± 0.03. Similarly, the genetic correlation between HCW and RT was 0.26 ± 0.04, and between HCW and LIV was 0.09 ± 0.05, respectively. The positive and moderate genetic correlations between BW and other traits imply a heavier BW resulted in a higher probability of surviving to harvest. Genetic correlations between HCW and other traits were lower due to the large quantity of missing records. Despite the heritable and correlated aspects of RT and LIV, results imply no major differences between M1 and M2; hence, it is unnecessary to include these traits in classical models for BW and HCW.


Assuntos
Hibridização Genética , Modelos Genéticos , Animais , Peso ao Nascer , Peso Corporal , Feminino , Paridade , Linhagem , Fenótipo , Gravidez , Suínos/genética
9.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445325

RESUMO

Blue cone monochromatism (BCM) is an X-linked recessive cone dysfunction disorder caused by mutations in the OPN1LW/OPN1MW gene cluster, encoding long (L)- and middle (M)-wavelength-sensitive cone opsins. Here, we report on the unusual clinical presentation of BCM caused by a novel mutation in the OPN1LW gene in a young man. We describe in detail the phenotype of the proband, and the subclinical morpho-functional anomalies shown by his carrier mother. At a clinical level, the extensive functional evaluation demonstrated in the proband the M/L cone affection and the sparing of S-cone function, distinctive findings of BCM. Interestingly, spectral-domain optical coherence tomography showed the presence of foveal hypoplasia with focal irregularities of the ellipsoid layer in the foveal area, reported to be associated with some cases of cone-rod dystrophy and achromatopsia. At a molecular level, we identified the novel mutation c.427T > C p.(Ser143Pro) in the OPN1LW gene and the common missense mutation c.607T > C (p.Cys203Arg) in the OPN1MW gene. In addition, we discovered the c.768-2_769delAGTT splicing variant in the GPR143 gene. To our knowledge, this is the first case of foveal hypoplasia in a BCM patient and of mild clinical affection in a female carrier caused by the concomitant effect of variants in OPN1LW/OPN1MW and GPR143 genes, thus as the result of the simultaneous action of two independent genetic defects.


Assuntos
Defeitos da Visão Cromática/genética , Proteínas do Olho/genética , Fóvea Central/anormalidades , Glicoproteínas de Membrana/genética , Opsinas de Bastonetes/genética , Adulto , Defeitos da Visão Cromática/patologia , Humanos , Masculino , Mutação , Linhagem
10.
J Anim Sci ; 99(9)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34390341

RESUMO

Genomic selection has been adopted nationally and internationally in different livestock and plant species. However, understanding whether genomic selection has been effective or not is an essential question for both industry and academia. Once genomic evaluation started being used, estimation of breeding values with pedigree best linear unbiased prediction (BLUP) became biased because this method does not consider selection using genomic information. Hence, the effective starting point of genomic selection can be detected in two possible ways including the divergence of genetic trends and Realized Mendelian sampling (RMS) trends obtained with BLUP and single-step genomic BLUP (ssGBLUP). This study aimed to find the start date of genomic selection for a set of economically important traits in three livestock species by comparing trends obtained using BLUP and ssGBLUP. Three datasets were used for this purpose: 1) a pig dataset with 117k genotypes and 1.3M animals in pedigree, 2) an Angus cattle dataset consisted of ~842k genotypes and 11.5M animals in pedigree, and 3) a purebred broiler chicken dataset included ~154k genotypes and 1.3M birds in pedigree were used. The genetic trends for pigs diverged for the genotyped animals born in 2014 for average daily gain (ADG) and backfat (BF). In beef cattle, the trends started diverging in 2009 for weaning weight (WW) and in 2016 for postweaning gain (PWG), with little divergence for birth weight (BTW). In broiler chickens, the genetic trends estimated by ssGBLUP and BLUP diverged at breeding cycle 6 for two out of the three production traits. The RMS trends for the genotyped pigs diverged for animals born in 2014, more for ADG than for BF. In beef cattle, the RMS trends started diverging in 2009 for WW and in 2016 for PWG, with a trivial trend for BTW. In broiler chickens, the RMS trends from ssGBLUP and BLUP diverged strongly for two production traits at breeding cycle 6, with a slight divergence for another trait. Divergence of the genetic trends from ssGBLUP and BLUP indicates the onset of the genomic selection. The presence of trends for RMS indicates selective genotyping, with or without the genomic selection. The onset of genomic selection and genotyping strategies agrees with industry practices across the three species. In summary, the effective start of genomic selection can be detected by the divergence between genetic and RMS trends from BLUP and ssGBLUP.


Assuntos
Galinhas , Modelos Genéticos , Animais , Bovinos/genética , Galinhas/genética , Genoma , Genômica , Genótipo , Linhagem , Fenótipo , Suínos/genética
11.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(8): 761-764, 2021 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-34365619

RESUMO

OBJECTIVE: To explore the genetic basis for a child with moderate non-syndromic hearing loss. METHODS: Next generation sequencing was carried out for the child. Co-segregation of the phenotype and candidate variants was verified among his family members by Sanger sequencing. RESULTS: The child was found to harbor biallelic variants of the OTOGL gene, namely c.2773C>T (p.Arg925Ter) and c.2826C>G (p.Tyr942Ter), which were respectively inherited from his phenotypically normal father and mother. Both variants were predicted to cause premature termination of protein synthesis and be disease causing by MutationTaster software. The c.2826C>G (p.Tyr942Ter) variant has not been recorded in the Human Gene Mutation Database. Based on the guidelines of the American College of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+PM2+PM4+PP3+PP5 and PVS1+PM2+PM4+PP3, respectively). CONCLUSION: The c.2773C>T (p.Arg925Ter) and c.2826C>G (p.Tyr942Ter) variants of the OTOGL gene probably underlay the hearing loss in this child.


Assuntos
Surdez , Criança , Família , Genômica , Humanos , Proteínas de Membrana/genética , Mutação , Linhagem , Fenótipo
12.
Trop Anim Health Prod ; 53(4): 432, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34373940

RESUMO

The multiple sire system (MSS) is a common mating scheme in extensive beef production systems. However, MSS does not allow paternity identification and lead to inaccurate genetic predictions. The objective of this study was to investigate the implementation of single-step genomic BLUP (ssGBLUP) in different scenarios of uncertain paternity in the evaluation for 450-day adjusted liveweight (W450) and age at first calving (AFC) in a Nellore cattle population. To estimate the variance components using BLUP and ssGBLUP, the relationship matrix (A) with different proportions of animals with missing sires (MS) (scenarios 0, 25, 50, 75, and 100% of MS) was created. The genotyped animals with MS were randomly chosen, and ten replicates were performed for each scenario and trait. Five groups of animals were evaluated in each scenario: PHE, all animals with phenotypic records in the population; SIR, proven sires; GEN, genotyped animals; YNG, young animals without phenotypes and progeny; and YNGEN, young genotyped animals. The additive genetic variance decreased for both traits as the proportion of MS increased in the population when using the regular REML. When using the ssGBLUP, accuracies ranged from 0.13 to 0.47 for W450 and from 0.10 to 0.25 for AFC. For both traits, the prediction ability of the direct genomic value (DGV) decreased as the percentage of MS increased. These results emphasize that indirect prediction via DGV of young animals is more accurate when the SNP effects are derived from ssGBLUP with a reference population with known sires. The ssGBLUP could be applied in situations of uncertain paternity, especially when selecting young animals. This methodology is shown to be accurate, mainly in scenarios with a high percentage of MS.


Assuntos
Genoma , Modelos Genéticos , Animais , Bovinos/genética , Genômica , Genótipo , Linhagem , Fenótipo
13.
Ugeskr Laeger ; 183(29)2021 07 19.
Artigo em Dinamarquês | MEDLINE | ID: mdl-34356019

RESUMO

This is a case report of a patient, who was diagnosed with epilepsy (atypical infantile convulsions) at the age of one year and unspecific myopathy at the age of three years. At the age of 25 years, the patient was referred to a neuromuscular clinic due to myopathy, but the diagnose was changed to atypical infantile convulsions with seizures in adulthood and paroxysmal choreoathetosis due to a pathogenic variant c.970G>A, p. (Gly324Arg) in the PRRT2 gene.


Assuntos
Discinesias , Epilepsia Neonatal Benigna , Adulto , Discinesias/etiologia , Humanos , Lactente , Proteínas de Membrana/genética , Mutação , Proteínas do Tecido Nervoso/genética , Linhagem
14.
J Anim Sci ; 99(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34378037

RESUMO

Genomic selection relies on single-nucleotide polymorphisms (SNPs), which are often collected using medium-density SNP arrays. In mink, no such array is available; instead, genotyping by sequencing (GBS) can be used to generate marker information. Here, we evaluated the effect of genomic selection for mink using GBS. We compared the estimated breeding values (EBVs) from single-step genomic best linear unbiased prediction (SSGBLUP) models to the EBV from ordinary pedigree-based BLUP models. We analyzed seven size and quality traits from the live grading of brown mink. The phenotype data consisted of ~20,600 records for the seven traits from the mink born between 2013 and 2016. Genotype data included 2,103 mink born between 2010 and 2014, mostly breeding animals. In total, 28,336 SNP markers from 391 scaffolds were available for genomic prediction. The pedigree file included 29,212 mink. The predictive ability was assessed by the correlation (r) between progeny trait deviation (PTD) and EBV, and the regression of PTD on EBV, using 5-fold cross-validation. For each fold, one-fifth of animals born in 2014 formed the validation set. For all traits, the SSGBLUP model resulted in higher accuracies than the BLUP model. The average increase in accuracy was 15% (between 3% for fur clarity and 28% for body weight). For three traits (body weight, silky appearance of the under wool, and guard hair thickness), the difference in r between the two models was significant (P < 0.05). For all traits, the regression slopes of PTD on EBV from SSGBLUP models were closer to 1 than regression slopes from BLUP models, indicating SSGBLUP models resulted in less bias of EBV for selection candidates than the BLUP models. However, the regression coefficients did not differ significantly. In conclusion, the SSGBLUP model is superior to conventional BLUP model in the accurate selection of superior animals, and, thus, it would increase genetic gain in a selective breeding program. In addition, this study shows that GBS data work well in genomic prediction in mink, demonstrating the potential of GBS for genomic selection in livestock species.


Assuntos
Genoma , Vison , Animais , Peso Corporal/genética , Genômica , Genótipo , Vison/genética , Modelos Genéticos , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único
15.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360608

RESUMO

Achromatopsia (ACHM) is a rare autosomal recessively inherited retinal disease characterized by congenital photophobia, nystagmus, low visual acuity, and absence of color vision. ACHM is genetically heterogeneous and can be caused by biallelic mutations in the genes CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, or ATF6. We undertook molecular genetic analysis in a single female patient with a clinical diagnosis of ACHM and identified the homozygous variant c.778G>C;p.(D260H) in the CNGA3 gene. While segregation analysis in the father, as expected, identified the CNGA3 variant in a heterozygous state, it could not be displayed in the mother. Microsatellite marker analysis provided evidence that the homozygosity of the CNGA3 variant is due to partial or complete paternal uniparental isodisomy (UPD) of chromosome 2 in the patient. Apart from the ACHM phenotype, the patient was clinically unsuspicious and healthy. This is one of few examples proving UPD as the underlying mechanism for the clinical manifestation of a recessive mutation in a patient with inherited retinal disease. It also highlights the importance of segregation analysis in both parents of a given patient or especially in cases of homozygous recessive mutations, as UPD has significant implications for genetic counseling with a very low recurrence risk assessment in such families.


Assuntos
Cromossomos Humanos Par 2/genética , Defeitos da Visão Cromática/patologia , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Pai , Mutação , Dissomia Uniparental , Adolescente , Defeitos da Visão Cromática/genética , Feminino , Genes Recessivos , Humanos , Masculino , Linhagem , Fenótipo
16.
Int J Mol Sci ; 22(15)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34360639

RESUMO

LMNA-related dilated cardiomyopathy is an inherited heart disease caused by mutations in the LMNA gene encoding for lamin A/C. The disease is characterized by left ventricular enlargement and impaired systolic function associated with conduction defects and ventricular arrhythmias. We hypothesized that LMNA-mutated patients' induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs) display electrophysiological abnormalities, thus constituting a suitable tool for deciphering the arrhythmogenic mechanisms of the disease, and possibly for developing novel therapeutic modalities. iPSC-CMs were generated from two related patients (father and son) carrying the same E342K mutation in the LMNA gene. Compared to control iPSC-CMs, LMNA-mutated iPSC-CMs exhibited the following electrophysiological abnormalities: (1) decreased spontaneous action potential beat rate and decreased pacemaker current (If) density; (2) prolonged action potential duration and increased L-type Ca2+ current (ICa,L) density; (3) delayed afterdepolarizations (DADs), arrhythmias and increased beat rate variability; (4) DADs, arrhythmias and cessation of spontaneous firing in response to ß-adrenergic stimulation and rapid pacing. Additionally, compared to healthy control, LMNA-mutated iPSC-CMs displayed nuclear morphological irregularities and gene expression alterations. Notably, KB-R7943, a selective inhibitor of the reverse-mode of the Na+/Ca2+ exchanger, blocked the DADs in LMNA-mutated iPSC-CMs. Our findings demonstrate cellular electrophysiological mechanisms underlying the arrhythmias in LMNA-related dilated cardiomyopathy.


Assuntos
Arritmias Cardíacas/patologia , Cálcio/metabolismo , Cardiomiopatia Dilatada/patologia , Células-Tronco Pluripotentes Induzidas/patologia , Lamina Tipo A/genética , Mutação , Miócitos Cardíacos/patologia , Potenciais de Ação , Adulto , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/metabolismo , Diferenciação Celular , Fenômenos Eletrofisiológicos , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/metabolismo , Linhagem
17.
Int J Mol Sci ; 22(15)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34360642

RESUMO

The purpose of this work was to identify the gene defect underlying a relatively mild rod-cone dystrophy (RCD), lacking disease-causing variants in known genes implicated in inherited retinal disorders (IRD), and provide transcriptomic and immunolocalization data to highlight the best candidate. The DNA of the female patient originating from a consanguineous family revealed no large duplication or deletion, but several large homozygous regions. In one of these, a homozygous frameshift variant, c.244_246delins17 p.(Trp82Valfs*4); predicted to lead to a nonfunctional protein, was identified in CCDC51. CCDC51 encodes the mitochondrial coiled-coil domain containing 51 protein, also called MITOK. MITOK ablation causes mitochondrial dysfunction. Here we show for the first time that CCDC51/MITOK localizes in the retina and more specifically in the inner segments of the photoreceptors, well known to contain mitochondria. Mitochondrial proteins have previously been implicated in IRD, although usually in association with syndromic disease, unlike our present case. Together, our findings add another ultra-rare mutation implicated in non-syndromic IRD, whose pathogenic mechanism in the retina needs to be further elucidated.


Assuntos
Distrofias de Cones e Bastonetes/patologia , Genes Recessivos , Proteínas Mitocondriais/genética , Mutação , Canais de Potássio/genética , Adulto , Distrofias de Cones e Bastonetes/etiologia , Distrofias de Cones e Bastonetes/metabolismo , Feminino , Humanos , Masculino , Linhagem , Fenótipo
18.
Nat Commun ; 12(1): 4680, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344887

RESUMO

Craniofacial microsomia (CFM) is the second most common congenital facial anomaly, yet its genetic etiology remains unknown. We perform whole-exome or genome sequencing of 146 kindreds with sporadic (n = 138) or familial (n = 8) CFM, identifying a highly significant burden of loss of function variants in SF3B2 (P = 3.8 × 10-10), a component of the U2 small nuclear ribonucleoprotein complex, in probands. We describe twenty individuals from seven kindreds harboring de novo or transmitted haploinsufficient variants in SF3B2. Probands display mandibular hypoplasia, microtia, facial and preauricular tags, epibulbar dermoids, lateral oral clefts in addition to skeletal and cardiac abnormalities. Targeted morpholino knockdown of SF3B2 in Xenopus results in disruption of cranial neural crest precursor formation and subsequent craniofacial cartilage defects, supporting a link between spliceosome mutations and impaired neural crest development in congenital craniofacial disease. The results establish haploinsufficient variants in SF3B2 as the most prevalent genetic cause of CFM, explaining ~3% of sporadic and ~25% of familial cases.


Assuntos
Síndrome de Goldenhar/genética , Haploinsuficiência , Fatores de Processamento de RNA/genética , Adolescente , Adulto , Animais , Criança , Exoma/genética , Feminino , Estudos de Associação Genética , Síndrome de Goldenhar/patologia , Humanos , Lactente , Masculino , Mutação , Crista Neural/crescimento & desenvolvimento , Crista Neural/patologia , Linhagem , Spliceossomos/genética , Xenopus laevis
19.
BMC Ophthalmol ; 21(1): 302, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34399712

RESUMO

BACKGROUND: Retinitis pigmentosa (RP) is a rare, progressive, and hereditary disorder that leads to the progressive loss of vision and visual field, and in some cases blindness. The specific relationship between RP and glaucoma has been debated for decades. METHODS: In this study, we examined a Han RP family with concomitant angle-closure glaucoma (ACG), performed an inductive analysis of their clinical features and assistant results, and applied whole-exome sequencing (WES) technology for a molecular diagnosis. RESULTS: A novel transversion mutation (c.626 T > A) was identified in the peripherin-2 (PRPH2) gene in the proband, resulting in the substitution of Valine to aspartic acid in codon 209. A full ophthalmic examination showed that the proband with the c.626 T > A mutation had a typical RP manifestation, with close angles; however, the proband's elder brother, who lacked the novel mutation, had a normal fundus and open angles. CONCLUSION: Our results extend the genetic mutation spectrum of PRPH2 in RP, and provide evidence to support a genetic correlation between RP and ACG.


Assuntos
Glaucoma de Ângulo Fechado , Retinite Pigmentosa , Idoso , China , Glaucoma de Ângulo Fechado/genética , Humanos , Masculino , Mutação , Linhagem , Retinite Pigmentosa/genética
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