Thesis (Ph.D.)--University of Alabama at Birmingham, 2007. / Title from PDF title page (viewed on Feb. 19, 2010). Includes bibliographical references.

Abstract Stickler and Marshall syndromes are genetic disorders both inherited in an autosomal dominant manner. The genotype-phenotype correlation was performed in ten Stickler/Marshall syndrome patients with mutations in the COL11A1 gene. Four patients had a phenotype classified as Marshall syndrome based on early-onset severe hearing loss and characteristic facial dysmorphism. A splice site mutation in intron 50 of COL11A1 was found in these patients, while the remaining six patients had an overlapping Marshall-Stickler phenotype with a mutation elsewhere in the gene. These results indicate exon 50 as a hot spot for splice site mutations leading to a phenotype of Marshall syndrome rather than Stickler syndrome. Collagen II (COL2A1) precursor mRNA undergoes alternative splicing resulting in two different isoforms, IIA including exon 2 and IIB excluding exon 2. Recent evidence indicates that premature termination codon mutations in exon 2 cause Stickler syndrome with no or minimal extraocular manifestations. Two mutations were observed in this study: Cys64Stop, and a novel structural mutation, Cys57Tyr. Results from the COL2A1 mini-gene studies suggested that both mutations altered positive cis elements for splicing resulting in a lower IIA:IIB ratio. The results further emphasize the importance of exon 2 in the development and normal function of the eye. In addition, patients displaying eye phenotypes in the absence of extraocular manifestations should be analyzed first for exon 2 mutations. Linkage analysis identified a new locus for autosomal recessive nonsyndromic hearing loss (DFNB32) on chromosome 1p13.3-22.1 in a Tunisian family with congenital profound autosomal recessive deafness. The COL11A1 gene is located in this region and was analyzed as a candidate gene. No disease causing sequence variation was observed. The analysis of 85 English and 40 Finnish subjects with high myopia resulted in the identification 23 sequence variations in the SLRP genes LUM, FMOD, PRELP, and OPTC. The two intronic variations and seven amino acid changes, one synonymous and six non-synonymous, were not found in the 308 controls analyzed. Five changes were detected in opticin, and all but one were shown to co-segregate with high myopia in families with incomplete penetrance. The results suggested that sequence variations in the SLRP genes expressed in the eye are genetic risk factors underlying the pathogenesis of high myopia.

During the past 500 years, the Bahamas has been influenced by a wide array of settlers, including but not limited to, the Arawak Indians, Eleutherian Adventurers, British Loyalists, Creole slaves, liberated Africans as well as Chinese, Greek, Jewish, Lebanese, Jamaican and Haitian migrants. To date, however, only a few reports analyzing the genetic makeup and population dynamics of the Bahamas have been published, making this work pivotal in the endeavor to ascertain the genetic ancestry of these groups. As such, the current investigation was undertaken to genetically characterize six of the more densely populated islands throughout the Northwest (Grand Bahama and Abaco) and Central (Eleuthera, Exuma, Long Island and New Providence) Bahamas using different forensic marker systems. When autosomal STR markers are employed, the Bahamian collections were all found to receive differential contributions from the African, European, East Asian and Native American collections utilized in the analyses. Similar findings were also observed for two other Afro-Caribbean populations, Haiti and Jamaica, although the latter populace was found to share a greater proportion of its autosomal component with non-African sources than the former. On the contrary, analysis of the six Bahamian collections using high-resolution Y-chromosome markers identifies genetic signals emanating exclusively from Africans and Europeans, but this is likely the result of smaller sample sizes collected from each island and/or sex-biased gene flow from East Asian and Native American groups.

Klinefelter Syndrome (KS) is a multisystemic disorder associated with a plethora of phenotypic features including mental retardation, cardiac abnormalities, osteoporosis, infertility, gynecomastia, type two diabetes and increased cancer risk. KS is the most common aneuploidy in humans (with a prevalence of 1:500 to 1:1000 born males) and is characterized by one or more supernumerary X-chromosomes (47-XXY, 48-XXXY, and 49-XXXXY karyotypes). While X-chromosome inactivation (XCI) represses extra Xs, few genes called “escape genes” elude the XCI mechanism and are actively transcribed from X inactive. The overdosage of escape genes has been considered the molecular landscape that underlies KS clinical features. In this project, we exploit an integration-free reprogramming method to generate the largest described cohort of iPSCs from seven patients with KS and healthy donor fibroblasts from two relatives. The unicity of this cohort relies on the derivation of 47-XXY iPSCs and their isogenic 46-XY healthy counterparts, along with multiple rare 48-XXXY and 49-XXXXY iPSC lines. Through X chromosome inactivation (XCI) assessment, we show consistent retention of n-1 XCI in all derived KS-iPSCs. We identify the genes within the PAR1 region as the most susceptible to dosage-dependent transcriptional dysregulation and therefore putatively responsible for the progressively worsening phenotype in higher grade X aneuploidies. Moreover, we explore the transcriptional impact of X overdosage on autosomes and identify that the X-dosage-sensitive autosomal transcription factor NRF1 is a master regulator of the X-linked escape gene ZFX. Finally, we dissect the potential pathological impact of the escape gene KDM6A on low- and high-grade supernumerary X iPSCs and differentiated derivatives. We highlight a considerable proportion of KDM6A targets that could be responsible for paradigmatic clinical manifestations of KS.

Background: Complications related to peritoneal dialysis (PD) in patients with autosomal-dominant polycystic kidney disease (ADPKD), including intraperitoneal rupture of renal cyst, hernia, membrane failure and peritonitis, have been reported. However, long-term clinical outcomes of ADPKD patients on PD remain unclear. We performed this meta-analysis to assess the risks of death, technique failure and peritonitis in ADPKD patients on PD. Methods: A systematic review was conducted using MEDLINE, EMBASE and Cochrane databases from inception to October 2017 to identify studies that evaluated the outcomes of ADPKD patients on PD, including the risks of death, technique failure and peritonitis. Non-ADPKD patients on PD were used as controls. Effect estimates from the individual study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird. Results: Twelve cohort studies with a total of 14 673 patients on PD (931 ADPKD and 13 742 non-ADPKD patients) were enrolled. Compared with non-ADPKD status, ADPKD was associated with significantly decreased mortality risk with pooled odds ratio (OR) of 0.68 (95% confidence interval (CI), 0.53–0.86; I 2 = 0). There were no associations of ADPKD with the risks of technique failure of PD and peritonitis with pooled OR of 0.93 (95% CI, 0.79–1.10; I 2 = 0) and 0.88 (95% CI, 0.75–1.05; I 2 = 0), respectively. We found no publication bias as assessed by Egger's regression asymmetry test, with P = 0.90, 0.28 and 0.60 for the risks of mortality, technique failure and peritonitis in ADPKD patients on PD, respectively. Conclusion: Compared with non-ADPKD patients on PD, our study demonstrates that ADPKD patients on PD have 0.68-fold decreased mortality risk. There are no associations of ADPKD status with the risks of technique failure or peritonitis.

Gardner's syndrome is an autosomal dominant disease presenting multiple colonic polyps with a predisposition for malignant change. In addition to colonic polyp formation by early adolescence, extracolonic lesions appear often prior to polyp formation. One theoretical mechanism for the origin of polyps and malignancies in Gardner's syndrome is a genetic defect in the natural killer cell activity of patients with this disease. Natural killer cells are a of lymphocytes that spontaneously lyse tumor cells subpopulation and virally transformed cells. A study was undertaken to determine the natural killer activity of patients with Gardner's syndrome .

Polycystic kidney disease is an inherited degenerative disease in which the uriniferous tubules are replaced by expanding fluid-filled cysts that ultimately destroy organ function. Autosomal dominant polycystic kidney disease (ADPKD) is the most common form, afflicting approximately 1 in 1,000 people. It primarily is caused by mutations in the transmembrane proteins Polycystin-1 (PKD1) and Polycystin-2 (PKD2). The most proximal effects of polycystin mutations leading to cyst formation are not known, but pro-proliferative signaling must be involved for the tubule epithelial cells to increase in number over time. The stress-activated mitogen-activated protein kinase (MAPK) pathway c-Jun N-terminal kinase (JNK) promotes proliferation in specific contexts and is activated in acute and chronic kidney disease. Previous work found evidence of JNK activation in cystic tissues (Le et al., 2005) and others showed that JNK signaling is activated by aberrant expression of PKD1 and PKD2 in cell culture (Arnould et al., 1998; Arnould et al., 1999; Parnell et al., 2002; Yu et al., 2010) but the contribution of JNK signaling to cystic disease in vivo has not been investigated. This body of work describes the use of conditional and germline deletion of Pkd2, Jnk1 and Jnk2 to model ADPKD and JNK signaling inhibition in juvenile and adult mice. Immunoblots and histological staining were used to measure JNK activation and evaluate the effect of JNK deletion on cystic disease. Results show that Pkd2 deletion activated JNK signaling in juvenile and adult mice. Reduction of JNK activity significantly reduced cystic burden in kidneys of juvenile Pkd2 mutant mice. This correlated with reduced tubule cell proliferation and reduced kidney fibrosis. The improvement in cystic phenotype was driven primarily by Jnk1 deletion rather than Jnk2. JNK signaling inhibition in adult Pkd2 mutants significantly reduced liver cysts when mice were aged six months. JNK inhibition reduces the severity of cystic disease caused by the loss of Pkd2 suggesting that the JNK pathway should be explored as a potential therapeutic target for ADPKD.

Made available in DSpace on 2015-07-22T20:49:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-27 / A cafeína tem sido considerada um fator de risco para o crescimento dos cistos na Doença Renal Policística Autossômica Dominante (DRPAD) devido ao aumento de secreção de fluido e proliferação celular induzidos pelo acúmulo de adenosina monofosfato cíclico (AMPc’), resultante da inibição da fosfodiesterase. O presente estudo teve como objetivos quantificar a ingestão de cafeína discriminando entre suas fontes dietéticas, avaliar o conhecimento sobre a necessidade de restrição de cafeína pelos pacientes com DRPAD e determinar a associação entre o consumo de cafeína e os dados clínicos e laboratoriais destes pacientes. A avaliação dos hábitos alimentares e do consumo de cafeína foi realizada através de três recordatórios de 24 horas, em dias não consecutivos e o conhecimento sobre a restrição de cafeína, considerado como orientação prévia, foi avaliado ao término da última entrevista com o paciente. Foram incluídos no estudo 102 pacientes com DRPAD (68F/34M, 38±14 anos), acompanhados no Ambulatório de Rins Policísticos da Universidade Federal de São Paulo (UNIFESP) e 102 indivíduos saudáveis (74F/28M, 39±12 anos). Os dados clínicos, laboratoriais e parâmetros ultrassonográficos renais foram obtidos do prontuário destes pacientes. A ingestão de cafeína foi significantemente menor no grupo de pacientes DRPAD quando comparados aos controles (85,7 versus 134 mg/dia) e o volume renal não se correlacionou com a ingestão de cafeína. De acordo com as respostas, detectou-se que 63% dos pacientes DRPAD foram previamente orientados quanto à restrição de cafeína. Os pacientes nãoorientados, que consumiam significantemente mais cafeína do que os orientados, eram significantemente mais velhos, e apresentavam níveis significantemente maiores de creatinina sérica e menores de Taxa de Filtração Glomerular (TFG) estimada. A porcentagem de pacientes hipertensos e com Doença Renal Crônica (DRC) estágio 3 era maior neste grupo, porém sem atingir significância estatística. O volume renal tendeu a ser maior no grupo de pacientes não-orientados, mas sem significância estatística. A análise de regressão linear multivariada revelou que a idade, presença de hipertensão e DRC estágio 3 se associaram com o volume renal na amostra total. Em conclusão, o consumo de cafeína encontrou-se reduzido na presente amostra de pacientes com DRPAD, provavelmente, devido à orientação prévia quanto à necessidade de restrição. A cafeína não se associou de maneira independente com o volume renal, o qual sofreu maiores influências da idade, presença de hipertensão e DRC. / TEDE / BV UNIFESP: Teses e dissertações

Monogenic disorders, i.e., disorders caused by mutations in a single gene, are rare and clinically heterogeneous conditions. Identification of the genetic cause of monogenic traits can bring new insights into molecular pathways and disease mechanisms. The aims of the present study were to identify the mutant genes in two autosomal recessive skin disorders and to characterize the functions of the mutated genes.  In order to identify candidate genes for the two disorders whole-genome SNP analysis, homozygosity mapping and gene sequencing were used. Autosomal recessive congenital ichthyosis (ARCI) is a group of disorders characterized by extensive scaling and redness of the skin.  A subgroup of ARCI patients (n=27) was selected based on specific ultrastructural aberrations in their skin, revealed by electron microscopy. Mutations were identified in the Ichthyin gene in 93% of the selected patients, indicating a strong association between mutant Ichthyin and the specific morphological abnormalities. Ichthyin mRNA levels were shown to increase during keratinocyte differentiation in cells from healthy and affected individuals. Electron microscopy revealed a localization of ichthyin protein to keratins and desmosomes in epidermis. Staining of epidermal lipids identified aberrant lipid aggregates in skin sections of patients with Ichthyin mutations, indicating a role for Ichthyin in epidermal lipid metabolism. In twelve KLICK syndrome patients with ichthyosis, palmoplantar keratoderma and keratotic striae on joints, a single-nucleotide deletion was identified in the 5’ region of the proteasome maturation protein (POMP) gene.  The deletion caused an increase in the proportion of POMP transcripts with long 5’ UTR’s in patient keratinocytes.  Immunohistochemical analysis of differentiated skin cell layers revealed aberrant expression of POMP, proteasome subunits and the skin protein filaggrin in patients. CHOP expression, associated with endoplasmic reticulum stress, was increased in the same layers. siRNA silencing of POMP in cell cultures reduced proteasome subunit levels and induced expression of CHOP.  The results indicate that the mutation in KLICK patients causes POMP and proteasome insufficiency with subsequent cellular stress. This study conclusively contributes to the understanding of epidermal physiology and the pathogenesis of two inherited skin diseases.

Made available in DSpace on 2016-12-23T13:49:03Z (GMT). No. of bitstreams: 1 Lorena Schneider Almeida.pdf: 683869 bytes, checksum: 550e76756dab14ae47e0e2440cfba6ca (MD5) Previous issue date: 2013-02-28 / The Osteogenesis Imperfecta (OI) is a genetic disease characterized by structural defects of type I collagen protein or by reducing its biosynthesis causing decreased bone mass and predisposition to fractures and bone deformities. Approximately 90% of individuals with OI exhibit autosomal dominant inheritance caused by mutations in the genes COL1A1 and COL1A2. However, the number of genes linked to autosomal recessive forms of OI is increasing in the literature. The CRTAP gene was the second identified causing recessive inheritance OI. This gene has 6622 bp, seven exons and encodes a protein of 46.5 kDa. The CRTAP encoding the protein cartilage associated (CRTAP) which is part of the collagen 3-hydroxylation complex, responsible for post-translational modifications during the biosynthesis of collagen molecule. CRTAP mutations are related to severe and lethal form of the disease. The target of this research was evaluating the exons of CRTAP and its adjacent regions in OI patients from Espírito Santo thought the Single-Stranded Conformation Polymorphism (SSCP) screening of mutations and sequencing. We studied 24 patients with clinical diagnosis of OI from Hospital Infantil Nossa Senhora da Glória de Vitória, Brazil. The patients/ ages ranged from 2 to 16 years (median: 14.5). The sex proportion of the patients was 15 males and 9 females. Eleven patients have mild clinical symptoms of the disease, 5 show moderate symptoms and 9 were severe cases. The lethal OI cases were not obtained by methodological difficulties. We found the polymorphisms c.534C> T previously reported in exon 2 of the CRTAP gene in patients from sample. No pathogenic mutations were found in this study. The results of this study suggest that mutations in CRTAP are rare in ES population. These data may assist in developing more efficient methodological strategies for molecular diagnosis of OI / A Osteogênese Imperfeita (OI) é uma doença genética caracterizada por defeitos estruturais da proteína do colágeno tipo I ou por redução da sua biossíntese causando diminuição da massa óssea e a predisposição a fraturas e deformidades ósseas. Aproximadamente 90% dos indivíduos com OI apresentam herança autossômica dominante causada por mutações nos genes COL1A1 ou COL1A2. Contudo, é crescente o número de genes ligados à herança autossômica recessiva da OI descritos na literatura. O gene CRTAP foi o segundo gene identificado causando OI com herança recessiva. Este gene possui 6.622 pb, 7 exons e codifica uma proteína de 46,5 KDa. O gene CRTAP codifica a proteína da cartilagem associada (CRTAP) que faz parte do complexo prolil 3-hidroxilação, responsável por modificações pós-traducionais fundamentais durante a biossíntese da molécula de colágeno. Mutações no gene CRTAP estão relacionadas à forma grave ou letal da doença. Esta pesquisa teve como objetivo avaliar as porções codificantes do gene CRTAP e suas regiões adjacentes em pacientes com OI do estado do Espírito Santo por meio da técnica de triagem de mutações de Polimorfismo Conformacional de Fita Simples (SSCP) e sequenciamento. Foram estudados 24 pacientes com diagnóstico clínico de OI do Hospital Infantil Nossa Senhora da Glória de Vitória, Brasil. As idades dos pacientes variaram de 2 a 16 anos (mediana: 14,5 anos) sendo 15 indivíduos do sexo masculino e 9 do sexo feminino, 11 pacientes apresentam a forma leve da doença, 5 a forma moderada e 9 a forma grave da doença. Os casos letais de OI não foram obtidos por dificuldades metodológicas. Foi encontrado o polimorfismos c.534C>T no exon 2 do gene CRTAP, previamente relatado na literatura, em pacientes da amostra. Não foram identificadas mutações patogênicas neste estudo. Os resultados desse trabalho sugerem que mutações no gene CRTAP são raras na população com OI do ES, corroborando dados da literatura. Esses dados poderão auxiliar na elaboração de estratégias metodológicas mais eficientes para o diagnóstico molecular de OI