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Three unrelated patients with similar microdeletions of chromosome 14q32.11 with shared phenotypes including language and developmental delay, and four overlapping genes -CALM1, TTC7B, PSMC1, and RPS6KA5 have been presented. All four genes are expressed in the brain and have haploinsufficiency scores, which reflect low tolerance to loss of function variation. An insight on the genes in the overlapping region, which may influence the resulting phenotype has been provided. Given the three patients' similar phenotypes and lack of normal variation in this region, it was suggested that this microdeletion may be associated with developmental and language delay.
Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Calmodulina/genética , Transtornos do Desenvolvimento da Linguagem/genética , Proteínas/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Criança , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 14/genética , Hibridização Genômica Comparativa/métodos , Haploinsuficiência/genética , Humanos , Transtornos do Desenvolvimento da Linguagem/patologia , Masculino , Linhagem , FenótipoRESUMO
OBJECTIVE: To compare mosaicisms in prenatal chorionic villus samples (CVSs) with corresponding postpartum placental samples. METHOD: We collected placentas from 15 consecutive cases of mosaicism detected in CVSs and obtained five standardized samples on each placenta after delivery. All pre- and postnatal placental samples were uncultured and analyzed by high-resolution chromosomal microarray. RESULTS: Ten cases of mosaicism for whole chromosome aneuploidy (mWC) and five cases with mosaicism for (sub)chromosomal copy number variations (mCNVs) were included. In 5/10 mWC cases and in 4/5 mCNV cases the prenatally detected aberration was confirmed in the postpartum placenta. Three postpartum placentas revealed various complex aberrations differing from the prenatal results: (1) mosaicisms for different deletions/duplications on 9p and 9q in all samples (prenatal: mosaic 5.3 Mb duplication on 9p24), (2) different regions with deletions/duplications/loss of heterozygosity on 1p in all samples (prenatal: mosaic 2.3 Mb 1p36 duplication), and (3) mosaicism for a duplication on 5q and a deletion on 6p in one out of five samples (prenatal: mosaic trisomy 7). CONCLUSION: CNVs constitute a complex subgroup in placental mosaicism. Counseling of these couples after chorionic villus sampling should not focus on the specific CNV involved, but on the nature of mosaicism and the option of amniocentesis and ultrasound.
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Aneuploidia , Mosaicismo , Placenta/fisiopatologia , Adulto , Dinamarca , Feminino , Humanos , GravidezRESUMO
Mutations in parkin, encoded by the PARK2 gene, causes early-onset familial Parkinson's disease (PD), but dysfunctional parkin has also been implicated in sporadic PD. By combining human isogenic induced pluripotent stem cells (iPSCs) with and without PARK2 knockout (KO) and a novel large-scale mass spectrometry based proteomics and post-translational modification (PTM)-omics approach, we have mapped changes in protein profiles and PTMs caused by parkin deficiency in neurons. Our study identifies changes to several proteins previously shown to be dysregulated in brains of sporadic PD patients. Pathway analysis and subsequent in vitro assays reveal perturbations in migration and neurite outgrowth in the PARK2 KO neurons. We confirm the neurite defects using long-term engraftment of neurons in the striatum of immunosuppressed hemiparkinsonian adult rats. The GTP-binding protein RhoA was identified as a key upstream regulator, and RhoA activity was significantly increased in PARK2 KO neurons. By inhibiting RhoA signalling the migration and neurite outgrowth phenotypes could be rescued. Our study provides new insight into the pathogenesis of PD and demonstrates the broadly applicable potential of proteomics and PTMomics for elucidating the role of disease-causing mutations.
Assuntos
Movimento Celular/fisiologia , Neurônios Dopaminérgicos/metabolismo , Neurogênese/fisiologia , Doença de Parkinson/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Técnicas de Inativação de Genes , Humanos , Células-Tronco Pluripotentes Induzidas , Mutação , Doença de Parkinson/genética , Ratos , Transdução de Sinais/fisiologia , Ubiquitina-Proteína Ligases/deficiênciaRESUMO
The 17p13.1 microdeletion syndrome is a recently described genomic disorder with a core clinical phenotype of intellectual disability, poor to absent speech, dysmorphic features, and a constellation of more variable clinical features, most prominently microcephaly. We identified five subjects with copy-number variants (CNVs) on 17p13.1 for whom we performed detailed clinical and molecular studies. Breakpoint mapping and retrospective analysis of published cases refined the smallest region of overlap (SRO) for microcephaly to a genomic interval containing nine genes. Dissection of this phenotype in zebrafish embryos revealed a complex genetic architecture: dosage perturbation of four genes (ASGR1, ACADVL, DVL2, and GABARAP) impeded neurodevelopment and decreased dosage of the same loci caused a reduced mitotic index in vitro. Moreover, epistatic analyses in vivo showed that dosage perturbations of discrete gene pairings induce microcephaly. Taken together, these studies support a model in which concomitant dosage perturbation of multiple genes within the CNV drive the microcephaly and possibly other neurodevelopmental phenotypes associated with rearrangements in the 17p13.1 SRO.
Assuntos
Anormalidades Múltiplas/genética , Dosagem de Genes/genética , Deficiência Intelectual/genética , Microcefalia/genética , Acil-CoA Desidrogenase de Cadeia Longa/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas Reguladoras de Apoptose , Receptor de Asialoglicoproteína/genética , Sequência de Bases , Linhagem Celular , Pontos de Quebra do Cromossomo , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Proteínas Desgrenhadas , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Proteínas Associadas aos Microtúbulos/genética , Dados de Sequência Molecular , Fosfoproteínas/genética , Estudos Retrospectivos , Análise de Sequência de DNA , Síndrome de Smith-Magenis , Síndrome , Peixe-ZebraRESUMO
17q12 deletions and duplications are two distinct, recurrent chromosomal aberrations usually diagnosed by chromosomal microarray analysis (CMA). The aberrations encompass the genes, HNF1B, LHX1, and ACACA, among others. We here describe a large national cohort of 12 phenotyped patients with 17q12 deletions and 26 phenotyped patients with 17q12 duplications. The total cohort includes 19 index patients and 19 family members. We also reviewed the literature in order to further improve the basis for the counseling. We emphasize that renal disease, learning disability, behavioral abnormalities, epilepsy, autism, schizophrenia, structural brain abnormalities, facial dysmorphism, and joint laxity are features seen in both the 17q12 deletion syndrome and the reciprocal 17q12 duplication syndrome; and we extend the list of features seen in both patient categories to include strabismus, esophageal defects, and duodenal atresia. Delayed language development, learning disability, kidney involvement, and eye dysmorphism and strabismus were the most consistently shared features among patients with 17q12 deletion. Patients with 17q12 duplications were characterized by an extremely wide phenotypic spectrum, including a variable degree of learning disabilities, delayed language development, delayed motor milestones, and a broad range of psychiatric and neurological features. This patient group also included adults achieving an academic degree. Assessing index patients and non-index patients separately, our observations illustrate that an overall milder disease burden is seen, in particular in patients with 17q12 duplications who are ascertained on the duplication rather than the phenotype. This evidence may be useful in prenatal counseling. © 2016 Wiley Periodicals, Inc.
Assuntos
Deleção Cromossômica , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Duplicação Cromossômica , Cromossomos Humanos Par 17 , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Hibridização Genômica Comparativa , Dinamarca , Fácies , Humanos , Lactente , Recém-Nascido , Padrões de Herança , Fenótipo , Polimorfismo de Nucleotídeo Único , Sistema de Registros , Síndrome , Adulto JovemRESUMO
NSD1 point mutations, submicroscopic deletions and intragenic deletions are the major cause of Sotos syndrome, characterized by pre-postnatal generalized overgrowth with advanced bone age, learning disability, seizures, distinctive facial phenotype. Reverse clinical phenotype due to 5q35 microduplication encompassing NSD1 gene has been reported so far in 27 cases presenting with delayed bone age, microcephaly, failure to thrive and seizures in some cases, further supporting a gene dosage effect of NSD1 on growth regulation and neurological functions. Here we depict the clinical presentation of three new cases with 5q35 microduplication outlining a novel syndrome characterized by microcephaly, short stature, developmental delay and in some cases delayed bone maturation, without any typical facial or osseous anomalies.
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Deleção Cromossômica , Duplicação Cromossômica , Estudos de Associação Genética , Fenótipo , Síndrome de Sotos/diagnóstico , Síndrome de Sotos/genética , Adolescente , Pré-Escolar , Cromossomos Humanos Par 5 , Hibridização Genômica Comparativa , Fácies , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Duplicações Segmentares GenômicasRESUMO
Background: Genomic disorders caused by copy number variations (CNVs) are prevalent in patients with kidney disease; however, their contribution to chronic kidney failure (KF) of undetermined aetiology (uKF) is unclear. We screened patients with uKF aged 50 years or younger to establish the prevalence of causative CNVs. Methods: We enrolled patients with an onset of KF ≤50 years from suspected undetermined aetiology for initial review of medical records to exclude patients with clear-cut clinical or histopathological kidney diagnoses or patients with already established genetic kidney diseases. Next, we performed single nucleotide polymorphism (SNP) array-based CNV screening. All the detected CNVs were systematically classified and evaluated as possible causes of the patient's kidney disease. Patients with CNVs not explaining the kidney phenotype were additionally screened for causal variants in 540 genes using whole-genome sequencing. Results: We enrolled 172 patients, of whom 123 underwent SNP-array. Pathogenic CNVs corresponding to known genomic disorders were identified in 12 patients (9.8%). The identified genomic disorders provided a causative kidney diagnosis in three patients, all of whom had reached KF by age 18 years. The remaining nine patients had CNVs with unclear kidney disease causality. Subsequently, whole-genome sequencing provided a causative genetic diagnosis in an additional four patients, including two diagnostic sequence variants unrelated to the detected CNVs. Conclusions: Genomic disorders were prevalent in this cohort with uKF, and causative CNVs were identified in 5 of 123 patients. Further studies combining the analysis of CNVs and sequence variants are needed to clarify the causal role of genomic disorders in kidney disease.
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Chromosome 17p13.3 is a gene rich region that when deleted is associated with the well-known Miller-Dieker syndrome. A recently described duplication syndrome involving this region has been associated with intellectual impairment, autism and occasional brain MRI abnormalities. We report 34 additional patients from 21 families to further delineate the clinical, neurological, behavioral, and brain imaging findings. We found a highly diverse phenotype with inter- and intrafamilial variability, especially in cognitive development. The most specific phenotype occurred in individuals with large duplications that include both the YWHAE and LIS1 genes. These patients had a relatively distinct facial phenotype and frequent structural brain abnormalities involving the corpus callosum, cerebellar vermis, and cranial base. Autism spectrum disorders were seen in a third of duplication probands, most commonly in those with duplications of YWHAE and flanking genes such as CRK. The typical neurobehavioral phenotype was usually seen in those with the larger duplications. We did not confirm the association of early overgrowth with involvement of YWHAE and CRK, or growth failure with duplications of LIS1. Older patients were often overweight. Three variant phenotypes included cleft lip/palate (CLP), split hand/foot with long bone deficiency (SHFLD), and a connective tissue phenotype resembling Marfan syndrome. The duplications in patients with clefts appear to disrupt ABR, while the SHFLD phenotype was associated with duplication of BHLHA9 as noted in two recent reports. The connective tissue phenotype did not have a convincing critical region. Our experience with this large cohort expands knowledge of this diverse duplication syndrome.
Assuntos
1-Alquil-2-acetilglicerofosfocolina Esterase/genética , Proteínas 14-3-3/genética , Encéfalo/anormalidades , Transtornos do Comportamento Infantil/patologia , Transtornos Globais do Desenvolvimento Infantil/patologia , Cromossomos Humanos Par 17/genética , Duplicação Gênica , Proteínas Associadas aos Microtúbulos/genética , Adolescente , Adulto , Encéfalo/patologia , Criança , Transtornos do Comportamento Infantil/genética , Transtornos Globais do Desenvolvimento Infantil/genética , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , FenótipoRESUMO
Incontinentia pigmenti is an uncommon X-linked dominant neurocutaneous ectodermal dysplasia. The disorder is usually lethal in males in utero, although it may occasionally occur in males with somatic mosaicsism or Klinefelter syndrome. This is a case report of a rare case of incontinentia pigmenti in a newborn male who presented with characteristic skin eruptions following Blaschko's lines. Histopathology and genetic testing confirmed the diagnosis. The management of patients with incontinentia pigmenti may require a multidisciplinary approach, and early diagnosis is of great importance.
Assuntos
Incontinência Pigmentar , Síndrome de Klinefelter , Humanos , Incontinência Pigmentar/diagnóstico , Incontinência Pigmentar/genética , Recém-Nascido , MasculinoRESUMO
Telomeres are repetitive genetic material that cap and thereby protect the ends of chromosomes. Each time a cell divides, telomeres get shorter. Telomere length is mainly maintained by telomerase. This enzyme is present in high concentrations in the embryonic stem cells and in fast growing embryonic cells, and declines with age. It is still unclear to what extent there is telomerase in adult stem cells, but since these are the founder cells of cells of all the tissues in the body, understanding the telomere dynamics and expression of telomerase in adult stem cells is very important. In the present communication we focus on telomere expression and telomere length in stem cells, with a special focus on mesenchymal stem cells. We consider different mechanisms by which stem cells can maintain telomeres and also focus on the dynamics of telomere length in mesenchymal stem cells, both the overall telomere length and the telomere length of individual chromosomes.
Assuntos
Células-Tronco Mesenquimais/fisiologia , Telomerase/metabolismo , Telômero/fisiologia , Células-Tronco Adultas/enzimologia , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/ultraestrutura , Divisão Celular , Senescência Celular/fisiologia , Epigênese Genética , Humanos , Células-Tronco Mesenquimais/enzimologia , Células-Tronco Mesenquimais/ultraestrutura , Telomerase/genética , Telômero/genéticaRESUMO
BACKGROUND: Previous studies have demonstrated that telomeres in somatic cells are not randomly distributed at the end of the chromosomes. We hypothesize that these chromosome arm specific differences in telomere length (the telomere length pattern) may be actively maintained. In this study we investigate the existence and maintenance of the telomere length pattern in stem cells. For this aim we studied telomere length in primary human mesenchymal stem cells (hMSC) and their telomerase-immortalised counterpart (hMSC-telo1) during extended proliferation as well as after irradiation. Telomere lengths were measured using Fluorescence In Situ Hybridization (Q-FISH). RESULTS: A telomere length pattern was found to exist in primary hMSC's as well as in hMSC-telo1. This pattern is similar to what was previously found in lymphocytes and fibroblasts. The cells were then exposed to a high dose of ionizing radiation. Irradiation caused profound changes in chromosome specific telomere lengths, effectively destroying the telomere length pattern. Following long term culturing after irradiation, a telomere length pattern was found to re-emerge. However, the new telomere length pattern did not resemble the telomere length pattern observed before irradiation. CONCLUSION: Our findings indicate that a telomere length pattern does exist in mesenchymal stem cells and that the pattern is not actively re-established after destruction by irradiation.
Assuntos
Cromossomos Humanos/efeitos da radiação , Células-Tronco Mesenquimais/enzimologia , Células-Tronco Mesenquimais/efeitos da radiação , Telomerase/metabolismo , Telômero/efeitos da radiação , Linhagem Celular Transformada , Cromossomos Humanos/genética , Cromossomos Humanos/metabolismo , Humanos , Células-Tronco Mesenquimais/metabolismo , Sondas RNA/metabolismo , Radiação Ionizante , Telômero/genética , Telômero/metabolismo , Transdução GenéticaRESUMO
PURPOSE: To evaluate the reduction in the anterior capsule opening after phacoemulsification, continuous curvilinear capsulorhexis, and implantation of 1 of 2 acrylic intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Vejle Hospital, Vejle, Denmark. METHODS: Eighty-four patients (84 eyes) were included in a prospective randomized study. All had phacoemulsification followed by implantation of an IOL with a modified anterior edge (38 eyes) or a sharp anterior edge (46 eyes). One day (baseline) and 3 months postoperatively, the area of the anterior capsule opening was measured using retroillumination photographs. RESULTS: There was a significant reduction in the area of the anterior capsule opening from 1 day to 3 months postoperatively in both groups (P<.001). There was no significant difference in the reduction in the anterior capsule opening between the modified-edge IOL and the sharp-edged IOL (P = .313). The shrinkage was independent of the area of the anterior capsule opening at baseline. CONCLUSIONS: There was a reduction in the area of the anterior capsule opening in all patients. The design of the anterior edge of the 2 IOLs did not influence the degree of anterior capsule opening shrinkage. The shrinkage was independent of the size of the area 1 day postoperatively.
Assuntos
Resinas Acrílicas , Capsulorrexe , Contratura/etiologia , Cápsula do Cristalino/patologia , Lentes Intraoculares , Facoemulsificação , Complicações Pós-Operatórias , Idoso , Feminino , Humanos , Implante de Lente Intraocular , Masculino , Estudos Prospectivos , Desenho de Prótese , Fatores de TempoRESUMO
The prenatal abnormalities in patients with penta X syndrome appear late in pregnancy and are nonspecific. In contrast, the postnatal phenotype is well described although new findings are still revealed. Penta X syndrome is a result of successive nondisjunctions of the X chromosomes in both maternal meiotic divisions.
RESUMO
Methylation-based non-invasive prenatal testing of fetal aneuploidies is an alternative method that could possibly improve fetal aneuploidy diagnosis, especially for trisomy 13(T13) and trisomy 18(T18). Our aim was to study the methylation landscape in placenta DNA from trisomy 13, 18 and 21 pregnancies in an attempt to find trisomy-specific methylation differences better suited for non-invasive prenatal diagnosis. We have conducted high-resolution methylation specific bead chip microarray analyses assessing more than 450,000 CpGs analyzing placentas from 12 T21 pregnancies, 12 T18 pregnancies and 6 T13 pregnancies. We have compared the methylation landscape of the trisomic placentas to the methylation landscape from normal placental DNA and to maternal blood cell DNA. Comparing trisomic placentas to normal placentas we identified 217 and 219 differentially methylated CpGs for CVS T18 and CVS T13, respectively (delta ß>0.2, FDR<0.05), but only three differentially methylated CpGs for T21. However, the methylation differences was only modest (delta ß<0.4), making them less suitable as diagnostic markers. Gene ontology enrichment analysis revealed that the gene set connected to theT18 differentially methylated CpGs was highly enriched for GO terms related to"DNA binding" and "transcription factor binding" coupled to the RNA polymerase II transcription. In the gene set connected to the T13 differentially methylated CpGs we found no significant enrichments.
Assuntos
Transtornos Cromossômicos/metabolismo , Metilação de DNA , Síndrome de Down/metabolismo , Complicações na Gravidez/metabolismo , Primeiro Trimestre da Gravidez/metabolismo , Cromossomos Humanos Par 13/metabolismo , Cromossomos Humanos Par 18/metabolismo , Ilhas de CpG , Feminino , Humanos , Análise em Microsséries , Gravidez , Trissomia , Síndrome da Trissomia do Cromossomo 13 , Síndrome da Trissomía do Cromossomo 18RESUMO
Previous studies have indicated that average telomere length is partly inherited (Slagboom et al., 1994; Rufer et al., 1999) and that there is an inherited telomere pattern in each cell (Graakjaer et al., 2003); (Londoño-Vallejo et al., 2001). In this study, we quantify the importance of the initially inherited telomere lengths within cells, in relation to other factors that influence telomere length during life. We have estimated the inheritance by measuring telomere length in monozygotic (MZ) twins using Q-FISH with a telomere specific peptide nucleic acid (PNA)-probe. Homologous chromosomes were identified using subtelomeric polymorphic markers. We found that identical homologous telomeres from two aged MZ twins show significantly less differences in relative telomere length than when comparing the two homologues within one individual. This result means that towards the end of life, individual telomeres retain the characteristic relative length they had at the outset of life and that any length alteration during the lifespan impacts equally on genetically identical homologues. As the result applies across independent individuals, we conclude that, at least in lymphocytes, epigenetic/environmental effects on relative telomere length are relatively minor during life.
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Telômero/metabolismo , Zigoto/metabolismo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Humanos , Hibridização In Situ , Linfócitos/metabolismo , Modelos Biológicos , Estudos em Gêmeos como AssuntoRESUMO
Human chromosomes terminate in a number of repeats of the sequence TTAGGG. At birth, each chromosome end is equipped with approximately 15 kb of telomere sequence, but this sequence is shortened during each cell division. In cell cultures telomere shortening is associated with senescence, a phenomenon that has also been observed in normal adult tissues, indicating that telomere loss is associated with organismal ageing. Previous work has established that the rate of telomere loss in humans is age dependent, and recent work shows a sex-specific difference in telomere length and shortening in individuals over the age span of 20 to 75 years. Here, terminal restriction fragment lengths on DNA purified from whole blood were measured to examine the mean telomere length in a cross-sectional cohort of 816 Danish individuals of age 73 to 101 years. In this age group, females show a linear correlation between telomere length and age, whereas the pattern tends to be nonlinear (quadratic in age) for males. This difference in telomere length dynamics between the 2 sexes may be caused by several different mechanisms, including differences in selection by mortality, differences in leukocyte population or different telomerase expression pattern.
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Telômero/ultraestrutura , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Estudos de Coortes , Estudos Transversais , Dinamarca , Feminino , Humanos , Estudos Longitudinais , MasculinoRESUMO
A tight link exists between telomere length and both population doublings of a cell culture and age of a given organism. The more population doublings of the cell culture or the higher the age of the organism, the shorter the telomeres. The proposed model for telomere shortening, called the end replication problem, explains why the telomere erodes at each cellular turnover. Telomere length is regulated by a number of associated proteins through a number of different signaling pathways. The determinants of telomere length were studied using whole blood samples from 287 twin pairs aged 73 to 95 years. Structural equation models revealed that a model including additive genetic effects and non-shared environment was the best fitting model and that telomere length was moderately heritable, with an estimate that was sensitive to the telomere length standardization procedure. Sex-specific analyses showed lower heritability in males, although not statistically significant, which is in line with our earlier finding of a sex difference in telomere dynamics among the elderly and oldest-old.