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1.
J Am Coll Health ; 70(5): 1465-1475, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-32877621

RESUMO

Objective: This study's purpose was to examine whether disclosures to friends or family post-victimization was associated with emotional and academic consequences (e.g. feeling detached from others, getting worse grades) among students grouped by sexual identity and race intersections. Participants and Methods: We analyzed data from an online survey that was distributed to students (n = 6,331) at a university in the Southeast. Results: Path analyses indicated disclosure to friends and family partially mediated the relationship between victimization and consequences, such that an increase in the number of disclosures was associated with an increase in the number of consequences. These paths were significant among White sexual minority victims, sexual minority victims of color, White heterosexual students, and heterosexual students of color. Conclusions: These findings indicate that disclosure to informal sources is associated with amplified consequences, which may be ameliorated by training friends and family to respond to disclosures in a supportive manner.


Assuntos
Vítimas de Crime , Delitos Sexuais , Minorias Sexuais e de Gênero , Revelação , Amigos , Humanos , Estudantes/psicologia , Universidades , Violência
2.
Genetics ; 217(2)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33724415

RESUMO

Segmental duplications (SDs) are a class of long, repetitive DNA elements whose paralogs share a high level of sequence similarity with each other. SDs mediate chromosomal rearrangements that lead to structural variation in the general population as well as genomic disorders associated with multiple congenital anomalies, including the 7q11.23 (Williams-Beuren Syndrome, WBS), 15q13.3, and 16p12.2 microdeletion syndromes. Population-level characterization of SDs has generally been lacking because most techniques used for analyzing these complex regions are both labor and cost intensive. In this study, we have used a high-throughput technique to genotype complex structural variation with a single molecule, long-range optical mapping approach. We characterized SDs and identified novel structural variants (SVs) at 7q11.23, 15q13.3, and 16p12.2 using optical mapping data from 154 phenotypically normal individuals from 26 populations comprising five super-populations. We detected several novel SVs for each locus, some of which had significantly different prevalence between populations. Additionally, we localized the microdeletion breakpoints to specific paralogous duplicons located within complex SDs in two patients with WBS, one patient with 15q13.3, and one patient with 16p12.2 microdeletion syndromes. The population-level data presented here highlights the extreme diversity of large and complex SVs within SD-containing regions. The approach we outline will greatly facilitate the investigation of the role of inter-SD structural variation as a driver of chromosomal rearrangements and genomic disorders.


Assuntos
Transtornos Cromossômicos/genética , Anormalidades Craniofaciais/genética , Variação Estrutural do Genoma , Cardiopatias Congênitas/genética , Deficiência Intelectual/genética , Duplicações Segmentares Genômicas , Convulsões/genética , Síndrome de Williams/genética , Pontos de Quebra do Cromossomo , Deleção Cromossômica , Cromossomos Humanos Par 15/genética , Cromossomos Humanos Par 16/genética , Deficiências do Desenvolvimento/genética , Humanos , Transtornos Mentais/genética
3.
J Couns Psychol ; 67(1): 1-13, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31697119

RESUMO

Using minority stress theory with a sample of 522 atheist people from the United States, the present study examined the associations of discrimination, proximal minority stressors (stigma consciousness, internalized antiatheism, outness as atheist), and atheist group involvement with psychological distress and self-esteem. Atheist group involvement was associated positively with outness and self-esteem, and negatively with discrimination. Structural equation modeling indicated that discrimination and stigma consciousness yielded significant positive direct relations with distress, whereas outness yielded a significant negative direct relation with distress. Relatedly, discrimination yielded a significant negative direct relation with self-esteem and outness yielded a significant positive direct relation with self-esteem. There was a significant positive unique indirect relation of antiatheist discrimination with distress via the mediating role of stigma consciousness, but no other proximal variables. Multigroup invariance testing of this model did not yield evidence that the pattern of relations of the minority stressors with mental health outcomes differed significantly between participants who were and who were not involved in an atheist group. Implications of these findings for research, practice, and advocacy are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Grupos Minoritários/psicologia , Secularismo , Autoimagem , Estigma Social , Estresse Psicológico/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Psicológico/diagnóstico , Estados Unidos/epidemiologia , Adulto Jovem
4.
Genome Res ; 29(9): 1389-1401, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31481461

RESUMO

Low copy repeats (LCRs) are recognized as a significant source of genomic instability, driving genome variability and evolution. The Chromosome 22 LCRs (LCR22s) mediate nonallelic homologous recombination (NAHR) leading to the 22q11 deletion syndrome (22q11DS). However, LCR22s are among the most complex regions in the genome, and their structure remains unresolved. The difficulty in generating accurate maps of LCR22s has also hindered localization of the deletion end points in 22q11DS patients. Using fiber FISH and Bionano optical mapping, we assembled LCR22 alleles in 187 cell lines. Our analysis uncovered an unprecedented level of variation in LCR22s, including LCR22A alleles ranging in size from 250 to 2000 kb. Further, the incidence of various LCR22 alleles varied within different populations. Additionally, the analysis of LCR22s in 22q11DS patients and their parents enabled further refinement of the rearrangement site within LCR22A and -D, which flank the 22q11 deletion. The NAHR site was localized to a 160-kb paralog shared between the LCR22A and -D in seven 22q11DS patients. Thus, we present the most comprehensive map of LCR22 variation to date. This will greatly facilitate the investigation of the role of LCR variation as a driver of 22q11 rearrangements and the phenotypic variability among 22q11DS patients.


Assuntos
Síndrome da Deleção 22q11/genética , Mapeamento Cromossômico/métodos , Cromossomos Humanos Par 22/genética , Sequências Repetitivas de Ácido Nucleico , Animais , Linhagem Celular , Instabilidade Cromossômica , Evolução Molecular , Humanos , Hibridização in Situ Fluorescente , Primatas/genética
5.
J Couns Psychol ; 66(2): 131-142, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30702325

RESUMO

Synthesizing both objectification theory (Fredrickson & Roberts, 1997) and minority stress theory (Meyer, 2003), the present study used a pantheoretical model of dehumanization (Moradi, 2013) to examine body image concerns and disordered eating symptomatology with 205 transgender women from the United States. Objectification theory constructs (i.e., sexual objectification, internalization of sociocultural standards of attractiveness, body surveillance, body dissatisfaction) and minority stress-related variables (i.e., antitransgender discrimination) were examined as direct and indirect predictors of disordered eating. Results of a latent variable SEM (with a higher-order dehumanization factor comprised of sexual objectification and discrimination) generally provided support for our hypothesized direct and indirect relations. As expected, dehumanization was related directly to internalization and disordered eating and had significant indirect links to body surveillance, body dissatisfaction, and disordered eating via internalization. Potential implications of a pantheoretical model for future research with transgender women are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Imagem Corporal/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Estresse Psicológico/psicologia , Pessoas Transgênero/psicologia , Adolescente , Adulto , Idoso , Estudos Transversais , Mecanismos de Defesa , Desumanização , Transtornos da Alimentação e da Ingestão de Alimentos/epidemiologia , Feminino , Identidade de Gênero , Humanos , Pessoa de Meia-Idade , Autoimagem , Comportamento Sexual/psicologia , Minorias Sexuais e de Gênero/psicologia , Estresse Psicológico/epidemiologia , Adulto Jovem
6.
Hum Mol Genet ; 26(15): 2838-2849, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28449119

RESUMO

CblX (MIM309541) is an X-linked recessive disorder characterized by defects in cobalamin (vitamin B12) metabolism and other developmental defects. Mutations in HCFC1, a transcriptional co-regulator which interacts with multiple transcription factors, have been associated with cblX. HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. The HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutation of THAP11 also results in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with clinical and biochemical phenotypic features that overlap cblX, but who does not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant, c.240C > G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo demonstrated that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. The loss of THAP11 in zebrafish embryos results in craniofacial abnormalities including the complete loss of Meckel's cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work that demonstrated a role for HCFC1 in vertebrate craniofacial development. High throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development.


Assuntos
Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Vitamina B 12/metabolismo , Animais , Sequência de Bases , Região Branquial/metabolismo , Diferenciação Celular , Criança , Anormalidades Craniofaciais/genética , Fibroblastos , Regulação da Expressão Gênica/genética , Fator C1 de Célula Hospedeira/química , Fator C1 de Célula Hospedeira/genética , Fator C1 de Célula Hospedeira/metabolismo , Humanos , Mutação , Cultura Primária de Células , Transcrição Gênica , Vitamina B 12/genética , Peixe-Zebra/genética
7.
Cold Spring Harb Mol Case Stud ; 2(3): a000844, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27148590

RESUMO

Restrictive cardiomyopathy (RCM) is a rare cause of heart muscle disease with the highest mortality rate among cardiomyopathy types. The etiology of RCM is poorly understood, although genetic causes have been implicated, and syndromic associations have been described. Here, we describe a patient with an atrial septal defect and restrictive cardiomyopathy along with craniofacial anomalies and intellectual disabilities. Initial screening using chromosomal microarray analysis (CMA) identified a maternally inherited 2q13 microdeletion. The patient had many of the features reported in previous cases with the recurrent 2q13 microdeletion syndrome. However, the inheritance of the microdeletion from an unaffected mother combined with the low incidence (10%) and milder forms of cardiac defects in previously reported cases made the clinical significance of the CMA results unclear. Whole-exome sequencing (WES) with trio-based analysis was performed and identified a paternally inherited TMEM87B mutation (c.1366A>G, p.Asn456Asp) in the patient. TMEM87B, a highly conserved, transmembrane protein of currently unknown function, lies within the critical region of the recurrent 2q13 microdeletion syndrome. Furthermore, a recent study had demonstrated that depletion of TMEM87B in zebrafish embryos affected cardiac development and led to cardiac hypoplasia. Thus, by combining CMA and WES, we potentially uncover an autosomal-recessive disorder characterized by a severe cardiac phenotype caused by mutations in TMEM87B. This study expands the spectrum of phenotypes associated with the recurrent 2q13 microdeletion syndrome and also further suggests the role of TMEM87B in its etiology, especially the cardiac pathology.

8.
Hum Mol Genet ; 24(15): 4443-53, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25972376

RESUMO

Kabuki syndrome (KS) is a rare multiple congenital anomaly syndrome characterized by distinctive facial features, global developmental delay, intellectual disability and cardiovascular and musculoskeletal abnormalities. While mutations in KMT2D have been identified in a majority of KS patients, a few patients have mutations in KDM6A. We analyzed 40 individuals clinically diagnosed with KS for mutations in KMT2D and KDM6A. Mutations were detected in KMT2D in 12 and KDM6A in 4 cases, respectively. Observed mutations included single-nucleotide variations and indels leading to frame shifts, nonsense, missense or splice-site alterations. In two cases, we discovered overlapping chromosome X microdeletions containing KDM6A. To further elucidate the functional roles of KMT2D and KDM6A, we knocked down the expression of their orthologs in zebrafish. Following knockdown of kmt2d and the two zebrafish paralogs kdm6a and kdm6al, we analyzed morphants for developmental abnormalities in tissues that are affected in individuals with KS, including craniofacial structures, heart and brain. The kmt2d morphants exhibited severe abnormalities in all tissues examined. Although the kdm6a and kdm6al morphants had similar brain abnormalities, kdm6a morphants exhibited craniofacial phenotypes, whereas kdm6al morphants had prominent defects in heart development. Our results provide further support for the similar roles of KMT2D and KDM6A in the etiology of KS by using a vertebrate model organism to provide direct evidence of their roles in the development of organs and tissues affected in KS patients.


Assuntos
Anormalidades Múltiplas/genética , Proteínas de Ligação a DNA/genética , Face/anormalidades , Cardiopatias Congênitas/genética , Doenças Hematológicas/genética , Histona Desmetilases/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Doenças Vestibulares/genética , Peixe-Zebra/genética , Anormalidades Múltiplas/fisiopatologia , Animais , Encéfalo/anormalidades , Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiopatologia , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/fisiopatologia , Face/fisiopatologia , Cardiopatias Congênitas/fisiopatologia , Doenças Hematológicas/fisiopatologia , Humanos , Mutação , Doenças Vestibulares/fisiopatologia , Peixe-Zebra/crescimento & desenvolvimento
9.
J Med Genet ; 52(8): 532-40, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25787132

RESUMO

BACKGROUND: Mitochondrial disease is often suspected in cases of severe epileptic encephalopathy especially when a complex movement disorder, liver involvement and progressive developmental regression are present. Although mutations in either mitochondrial DNA or POLG are often present, other nuclear defects in mitochondrial DNA replication and protein translation have been associated with a severe epileptic encephalopathy. METHODS AND RESULTS: We identified a proband with an epileptic encephalopathy, complex movement disorder and a combined mitochondrial respiratory chain enzyme deficiency. The child presented with neurological regression, complex movement disorder and intractable seizures. A combined deficiency of mitochondrial complexes I, III and IV was noted in liver tissue, along with increased mitochondrial DNA content in skeletal muscle. Incomplete assembly of complex V, using blue native polyacrylamide gel electrophoretic analysis and complex I, using western blotting, suggested a disorder of mitochondrial transcription or translation. Exome sequencing identified compound heterozygous mutations in CARS2, a mitochondrial aminoacyl-tRNA synthetase. Both mutations affect highly conserved amino acids located within the functional ligase domain of the cysteinyl-tRNA synthase. A specific decrease in the amount of charged mt-tRNA(Cys) was detected in patient fibroblasts compared with controls. Retroviral transfection of the wild-type CARS2 into patient skin fibroblasts led to the correction of the incomplete assembly of complex V, providing functional evidence for the role of CARS2 mutations in disease aetiology. CONCLUSIONS: Our findings indicate that mutations in CARS2 result in a mitochondrial translational defect as seen in individuals with mitochondrial epileptic encephalopathy.


Assuntos
Aminoacil-tRNA Sintetases/genética , Encefalopatias/genética , Epilepsia/genética , Sequência de Aminoácidos , Aminoacilação , Criança , Análise Mutacional de DNA , Exoma , Humanos , Masculino , Dados de Sequência Molecular , RNA de Transferência/metabolismo , Alinhamento de Sequência
10.
Cultur Divers Ethnic Minor Psychol ; 21(1): 76-88, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25111543

RESUMO

Drawing from minority stress (Meyer, 2003) and feminist multicultural (Brown, 1994) theories, the present study investigated the additive and interactive relations between 2 types of external minority stress (heterosexist discrimination and racist events) and 4 internal stress processes related to identifying as a South Asian American lesbian, gay, bisexual, and queer (LGBQ) person (internalized heterosexism, acculturation, enculturation, and outness as LGBQ) with psychological distress. With 142 participants, Pearson's correlations, multiple regression, and simultaneous multiple moderation analyses were conducted. Experiences of heterosexist discrimination, racist events, and internalized heterosexism were correlated positively with psychological distress and enculturation was correlated negatively. In a test of the additive model, heterosexist discrimination, racist events, and internalized heterosexism accounted for significant and unique variance in psychological distress, but outness, acculturation, and enculturation did not. To test the interactive model, the simultaneous moderating roles of the internal stress processes were examined in the links between the external minority stressors to psychological distress. Only outness as LGBQ emerged as a moderator. The link between racist events and psychological distress was exacerbated in instances of higher outness, such that respondents with high racist events and high outness reported the highest levels of psychological distress. Clinical implications of these findings are discussed and future research directions focused on the needs of South Asian American LGBQ people are suggested.


Assuntos
Homossexualidade/psicologia , Minorias Sexuais e de Gênero/psicologia , Marginalização Social/psicologia , Aculturação , Adulto , Sudeste Asiático/etnologia , Feminino , Homossexualidade Feminina/psicologia , Homossexualidade Masculina/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Psicológico/psicologia , Estados Unidos
11.
Dev Biol ; 396(1): 94-106, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25281006

RESUMO

Mutations in HCFC1 (MIM300019), have been recently associated with cblX (MIM309541), an X-linked, recessive disorder characterized by multiple congenital anomalies including craniofacial abnormalities. HCFC1 is a transcriptional co-regulator that modulates the expression of numerous downstream target genes including MMACHC, but it is not clear how these HCFC1 targets play a role in the clinical manifestations of cblX. To begin to elucidate the mechanism by which HCFC1 modulates disease phenotypes, we have carried out loss of function analyses in the developing zebrafish. Of the two HCFC1 orthologs in zebrafish, hcfc1a and hcfc1b, the loss of hcfc1b specifically results in defects in craniofacial development. Subsequent analysis revealed that hcfc1b regulates cranial neural crest cell differentiation and proliferation within the posterior pharyngeal arches. Further, the hcfc1b-mediated craniofacial abnormalities were rescued by expression of human MMACHC, a downstream target of HCFC1 that is aberrantly expressed in cblX. Furthermore, we tested distinct human HCFC1 mutations for their role in craniofacial development and demonstrated variable effects on MMACHC expression in humans and craniofacial development in zebrafish. Notably, several individuals with mutations in either HCFC1 or MMACHC have been reported to have mild to moderate facial dysmorphia. Thus, our data demonstrates that HCFC1 plays a role in craniofacial development, which is in part mediated through the regulation of MMACHC expression.


Assuntos
Proteínas de Transporte/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Fator C1 de Célula Hospedeira/fisiologia , Proteínas de Peixe-Zebra/fisiologia , Animais , Padronização Corporal/genética , Região Branquial/fisiologia , Proteínas de Transporte/genética , Diferenciação Celular , Movimento Celular , Condrócitos/citologia , Anormalidades Craniofaciais/genética , Técnicas de Silenciamento de Genes , Proteínas de Fluorescência Verde/metabolismo , Fator C1 de Célula Hospedeira/genética , Humanos , Camundongos Transgênicos , Mutação , Crista Neural/citologia , Crista Neural/fisiologia , Oxirredutases , Fenótipo , Células-Tronco/citologia , Vitamina B 12/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
12.
Am J Med Genet A ; 164A(4): 950-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24458743

RESUMO

Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is an autosomal dominant disorder caused by mutations in FOXL2. We identified an individual with BPES and additional phenotypic features who did not have a FOXL2 mutation. We used whole exome sequencing to identify a de novo mutation in KAT6B (lysine acetyltransferase 6B) in this individual. The mutation was a 2-bp insertion leading to a frameshift which resulted in a premature stop codon. The resulting truncated protein does not have the C-terminal serine/methionine transcription activation domain necessary for interaction with other transcriptional and epigenetic regulators. This mutation likely has a dominant-negative or gain-of-function effect, similar to those observed in other genetic disorders resulting from KAT6B mutations, including Say-Barber-Biesecker-Young-Simpson (SBBYSS) and genitopatellar syndrome (GTPTS). Thus, our subject's phenotype broadens the spectrum of clinical findings associated with mutations in KAT6B. Furthermore, our results suggest that individuals with BPES without a FOXL2 mutation should be tested for KAT6B mutations. The transcriptional and epigenetic regulation mediated by KAT6B appears crucial to early developmental processes, which when perturbed can lead to a wide spectrum of phenotypic outcomes.


Assuntos
Blefarofimose/genética , Códon sem Sentido , Mutação da Fase de Leitura , Histona Acetiltransferases/genética , Anormalidades da Pele/genética , Proteína Forkhead Box L2 , Fatores de Transcrição Forkhead/genética , Humanos , Lactente , Masculino , Fenótipo , Anormalidades Urogenitais
13.
J Couns Psychol ; 61(1): 50-62, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24188653

RESUMO

In predicting disordered eating, the core model of objectification theory (Fredrickson & Roberts, 1997) has been replicated and extended in research across most sexual minority groups (e.g., Haines et al., 2008; Wiseman & Moradi, 2010), but not bisexual women. The present study tested the tenets of objectification theory with a sample of 316 bisexual women and further extended this theory by examining the roles of 2 minority stressors-antibisexual discrimination and internalized biphobia-that are contextually salient for bisexual women. A latent variable structural equation model was conducted, and the model yielded a good fit to the data. Antibisexual discrimination and internalized biphobia (but not sexual objectification experiences) yielded significant unique links with internalization of sociocultural standards of attractiveness (internalization of CSA). Next, internalization of CSA yielded a significant unique link with body surveillance. In addition, antibisexual discrimination, internalization of CSA, and body surveillance yielded significant unique links with body shame. Finally, sexual objectification experiences, internalization of CSA, and body shame yielded significant unique links with eating disorder symptomatology. Beyond the direct relations, antibisexual discrimination yielded significant positive indirect links with body surveillance, body shame, and eating disorder symptoms. Internalization of CSA yielded significant positive indirect links with body shame and eating disorder symptoms. Lastly, body surveillance yielded a significant positive indirect link with eating disorder symptoms. Implications for research and practice with bisexual women are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).


Assuntos
Pesquisa Biomédica/estatística & dados numéricos , Bissexualidade/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Transtornos da Alimentação e da Ingestão de Alimentos/terapia , Identidade de Gênero , Teoria Psicológica , Adolescente , Adulto , Idoso , Transtornos Dismórficos Corporais/diagnóstico , Transtornos Dismórficos Corporais/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Controle Interno-Externo , Pessoa de Meia-Idade , Preconceito/psicologia , Psicometria , Vergonha , Valores Sociais , Inquéritos e Questionários , Adulto Jovem
14.
Brain ; 137(Pt 2): 366-79, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24334290

RESUMO

Patients with nonketotic hyperglycinemia and deficient glycine cleavage enzyme activity, but without mutations in AMT, GLDC or GCSH, the genes encoding its constituent proteins, constitute a clinical group which we call 'variant nonketotic hyperglycinemia'. We hypothesize that in some patients the aetiology involves genetic mutations that result in a deficiency of the cofactor lipoate, and sequenced genes involved in lipoate synthesis and iron-sulphur cluster biogenesis. Of 11 individuals identified with variant nonketotic hyperglycinemia, we were able to determine the genetic aetiology in eight patients and delineate the clinical and biochemical phenotypes. Mutations were identified in the genes for lipoate synthase (LIAS), BolA type 3 (BOLA3), and a novel gene glutaredoxin 5 (GLRX5). Patients with GLRX5-associated variant nonketotic hyperglycinemia had normal development with childhood-onset spastic paraplegia, spinal lesion, and optic atrophy. Clinical features of BOLA3-associated variant nonketotic hyperglycinemia include severe neurodegeneration after a period of normal development. Additional features include leukodystrophy, cardiomyopathy and optic atrophy. Patients with lipoate synthase-deficient variant nonketotic hyperglycinemia varied in severity from mild static encephalopathy to Leigh disease and cortical involvement. All patients had high serum and borderline elevated cerebrospinal fluid glycine and cerebrospinal fluid:plasma glycine ratio, and deficient glycine cleavage enzyme activity. They had low pyruvate dehydrogenase enzyme activity but most did not have lactic acidosis. Patients were deficient in lipoylation of mitochondrial proteins. There were minimal and inconsistent changes in cellular iron handling, and respiratory chain activity was unaffected. Identified mutations were phylogenetically conserved, and transfection with native genes corrected the biochemical deficiency proving pathogenicity. Treatments of cells with lipoate and with mitochondrially-targeted lipoate were unsuccessful at correcting the deficiency. The recognition of variant nonketotic hyperglycinemia is important for physicians evaluating patients with abnormalities in glycine as this will affect the genetic causation and genetic counselling, and provide prognostic information on the expected phenotypic course.


Assuntos
Variação Genética/genética , Glutarredoxinas/genética , Hiperglicinemia não Cetótica/genética , Mutação/genética , Proteínas/genética , Sulfurtransferases/genética , Atrofia , Criança , Pré-Escolar , Evolução Fatal , Feminino , Glutarredoxinas/química , Humanos , Hiperglicinemia não Cetótica/diagnóstico , Hiperglicinemia não Cetótica/patologia , Lactente , Masculino , Proteínas Mitocondriais , Proteínas/química , Índice de Gravidade de Doença , Sulfurtransferases/química
15.
Am J Hum Genet ; 93(3): 506-14, 2013 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-24011988

RESUMO

Derivatives of vitamin B12 (cobalamin) are essential cofactors for enzymes required in intermediary metabolism. Defects in cobalamin metabolism lead to disorders characterized by the accumulation of methylmalonic acid and/or homocysteine in blood and urine. The most common inborn error of cobalamin metabolism, combined methylmalonic acidemia and hyperhomocysteinemia, cblC type, is caused by mutations in MMACHC. However, several individuals with presumed cblC based on cellular and biochemical analysis do not have mutations in MMACHC. We used exome sequencing to identify the genetic basis of an X-linked form of combined methylmalonic acidemia and hyperhomocysteinemia, designated cblX. A missense mutation in a global transcriptional coregulator, HCFC1, was identified in the index case. Additional male subjects were ascertained through two international diagnostic laboratories, and 13/17 had one of five distinct missense mutations affecting three highly conserved amino acids within the HCFC1 kelch domain. A common phenotype of severe neurological symptoms including intractable epilepsy and profound neurocognitive impairment, along with variable biochemical manifestations, was observed in all affected subjects compared to individuals with early-onset cblC. The severe reduction in MMACHC mRNA and protein within subject fibroblast lines suggested a role for HCFC1 in transcriptional regulation of MMACHC, which was further supported by the identification of consensus HCFC1 binding sites in MMACHC. Furthermore, siRNA-mediated knockdown of HCFC1 expression resulted in the coordinate downregulation of MMACHC mRNA. This X-linked disorder demonstrates a distinct disease mechanism by which transcriptional dysregulation leads to an inborn error of metabolism with a complex clinical phenotype.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/genética , Genes Ligados ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Fator C1 de Célula Hospedeira/genética , Hiper-Homocisteinemia/genética , Mutação/genética , Vitamina B 12/genética , Idade de Início , Sequência de Aminoácidos , Sítios de Ligação , Análise Mutacional de DNA , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Predisposição Genética para Doença , Células HEK293 , Fator C1 de Célula Hospedeira/química , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Ligação Proteica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas Repressoras/metabolismo
16.
Hum Mol Genet ; 20(5): 880-93, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21147756

RESUMO

Rare copy number variations (CNVs) are a recognized cause of common human disease. Predicting the genetic element(s) within a small CNV whose copy number loss or gain underlies a specific phenotype might be achieved reasonably rapidly for single patients. Identifying the biological processes that are commonly disrupted within a large patient cohort which possess larger CNVs, however, requires a more objective approach that exploits genomic resources. In this study, we first identified 98 large, rare CNVs within patients exhibiting multiple congenital anomalies. All patients presented with global developmental delay (DD), while other secondary symptoms such as cardiac defects, craniofacial features and seizures were varyingly presented. By applying a robust statistical procedure that matches patients' clinical phenotypes to laboratory mouse gene knockouts, we were able to strongly implicate anomalies in brain morphology and, separately, in long-term potentiation as manifestations of these DD patients' disorders. These and other significantly enriched model phenotypes provide insights into the pathoetiology of human DD and behavioral and anatomical secondary symptoms that are specific to DD patients. These enrichments set apart 103 genes, from among thousands overlapped by these CNVs, as strong candidates whose copy number change causally underlies approximately 46% of the cohort's DD syndromes and between 59 and 80% of the cohort's secondary symptoms. We also identified significantly enriched model phenotypes among genes overlapped by CNVs in both DD and learning disability cohorts, indicating a congruent etiology. These results demonstrate the high predictive potential of model organism phenotypes when implicating candidate genes for rare genomic disorders.


Assuntos
Variações do Número de Cópias de DNA , Deficiências do Desenvolvimento/genética , Animais , Estudos de Coortes , Deficiências do Desenvolvimento/psicologia , Modelos Animais de Doenças , Humanos , Aprendizagem , Camundongos , Camundongos Knockout , Fenótipo
17.
Am J Med Genet A ; 152A(12): 3074-83, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21108392

RESUMO

Deletions of chromosome 1p36 are one of the most frequently encountered subtelomeric alterations. Clinical features of monosomy 1p36 include neurocognitive impairment, hearing loss, seizures, cardiac defects, and characteristic facial features. The majority of cases have occurred sporadically, implying that genomic instability plays a role in the prevalence of the syndrome. Here, we report two siblings with mild phenotypic features of the deletion syndrome, including developmental delay, hearing loss, and left ventricular non-compaction (LVNC). Microarray analysis using bacterial artificial chromosome and oligonucleotide microarrays indicated the deletions were identical, suggesting germline mosaicism. Parental phenotypes were normal, and analysis by fluorescence in situ hybridization (FISH) did not show mosaicism. These small interstitial deletions were not detectable by conventional subtelomeric FISH analysis. To investigate the mechanism of deletion further, the breakpoints were cloned and sequenced, demonstrating the presence of a complex rearrangement. Sequence analysis of genes in the deletion interval did not reveal any mutations on the intact homologue that may have contributed to the LVNC seen in both children. This is the first report of apparent germline mosaicism for this disorder. Thus, our findings have important implications for diagnostic approaches and for recurrence risk counseling in families with a child with monosomy 1p36. In addition, our results further refine the minimal critical region for LVNC and hearing loss.


Assuntos
Quebra Cromossômica , Cromossomos Humanos Par 1 , Mosaicismo , Deleção de Sequência , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Pré-Escolar , Cromossomos Artificiais Bacterianos/genética , Hibridização Genômica Comparativa , DNA/genética , Deficiências do Desenvolvimento/genética , Feminino , Rearranjo Gênico/genética , Humanos , Hibridização in Situ Fluorescente , Lactente , Análise em Microsséries , Monossomia , Análise de Sequência com Séries de Oligonucleotídeos , Síndrome
18.
Am J Med Genet A ; 152A(1): 196-202, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20034085

RESUMO

We report here on a normal-appearing male with pervasive developmental disorder who was found to have a de novo, apparently balanced complex rearrangement involving chromosomes 6, 10, and 21: 46,XY,ins(21;10)(q11.2;p11.2p13)t(6;21)(p23;q11.2). Further analysis by high-density oligonucleotide microarray was performed, showing an 8.8-Mb heterozygous deletion at 21q21.1-q21.3. Interestingly, the deletion is distal to the translocation breakpoint on chromosome 21. The deletion involves 19 genes, including NCAM2 and GRIK1, both of which are associated with normal brain development and function, and have been considered as possible candidate genes in autism and other neurobehavioral disorders. This case underscores the utility of genomewide microarray analysis for the detection of copy number alterations in patients with apparently balanced complex rearrangements and abnormal phenotypes.


Assuntos
Transtorno Autístico/genética , Deleção Cromossômica , Cromossomos Humanos Par 10 , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 6 , Criança , Humanos , Hibridização in Situ Fluorescente , Masculino , Análise de Sequência com Séries de Oligonucleotídeos
20.
Genome Res ; 19(9): 1682-90, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19592680

RESUMO

We present a database of copy number variations (CNVs) detected in 2026 disease-free individuals, using high-density, SNP-based oligonucleotide microarrays. This large cohort, comprised mainly of Caucasians (65.2%) and African-Americans (34.2%), was analyzed for CNVs in a single study using a uniform array platform and computational process. We have catalogued and characterized 54,462 individual CNVs, 77.8% of which were identified in multiple unrelated individuals. These nonunique CNVs mapped to 3272 distinct regions of genomic variation spanning 5.9% of the genome; 51.5% of these were previously unreported, and >85% are rare. Our annotation and analysis confirmed and extended previously reported correlations between CNVs and several genomic features such as repetitive DNA elements, segmental duplications, and genes. We demonstrate the utility of this data set in distinguishing CNVs with pathologic significance from normal variants. Together, this analysis and annotation provides a useful resource to assist with the assessment of CNVs in the contexts of human variation, disease susceptibility, and clinical molecular diagnostics.


Assuntos
Mapeamento Cromossômico/métodos , Bases de Dados Genéticas , Dosagem de Genes/genética , Variação Genética , Genoma Humano/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , População Negra/genética , Criança , Duplicação Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Projetos de Pesquisa , População Branca/genética
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