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1.
Mol Genet Genomic Med ; : e973, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31568715

RESUMO

BACKGROUND: The nuclear encoded gene RMND1 (Required for Meiotic Nuclear Division 1 homolog) has recently been linked to RMND1-related mitochondrial disease (RRMD). This autosomal recessive condition characteristically presents with an infantile-onset multisystem disease characterized by severe hypotonia, global developmental delay, failure to thrive, sensorineural hearing loss, and lactic acidosis. Renal disease, however, appears to be one of the more prominent features of RRMD, affecting patients at significantly higher numbers compared to other mitochondrial diseases. We report the clinical, histological, and molecular findings of four RRMD patients across three academic institutions with a focus on the renal manifestations. METHODS: Four patients were identified for the purpose of this study, all of whom had molecular confirmation at the time of inclusion, which included the common pathogenic variant c.713A>G (p.N238S) as well as the three rare variants: c.485delC (p.P162fs), c.533C>T (p.T178M), and c.1317 + 1G>C splice donor variant. Medical history and laboratory findings were collected from the medical records and medical providers. RESULTS: In this study, all four patients developed renal disease characterized as tubulopathy (3/4), renal tubular acidosis (2/4), interstitial nephritis (1/4), and/or end-stage renal disease (4/4) necessitating renal transplantation (2/4). Histological evaluation of renal biopsy specimens revealed generalized tubular atrophy and on electron microscopy, abundant mitochondria with pleomorphism and abnormal cristae. CONCLUSION: Our experience with RRMD demonstrates a specific pattern of renal disease manifestations and clinical course. Patients are unlikely to respond to traditional chronic kidney disease (CKD) treatments, making early diagnosis and consideration of renal transplantation paramount to the management of RRMD.

2.
Am J Hum Genet ; 105(2): 302-316, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31256877

RESUMO

Members of a paralogous gene family in which variation in one gene is known to cause disease are eight times more likely to also be associated with human disease. Recent studies have elucidated DHX30 and DDX3X as genes for which pathogenic variant alleles are involved in neurodevelopmental disorders. We hypothesized that variants in paralogous genes encoding members of the DExD/H-box RNA helicase superfamily might also underlie developmental delay and/or intellectual disability (DD and/or ID) disease phenotypes. Here we describe 15 unrelated individuals who have DD and/or ID, central nervous system (CNS) dysfunction, vertebral anomalies, and dysmorphic features and were found to have probably damaging variants in DExD/H-box RNA helicase genes. In addition, these individuals exhibit a variety of other tissue and organ system involvement including ocular, outer ear, hearing, cardiac, and kidney tissues. Five individuals with homozygous (one), compound-heterozygous (two), or de novo (two) missense variants in DHX37 were identified by exome sequencing. We identified ten total individuals with missense variants in three other DDX/DHX paralogs: DHX16 (four individuals), DDX54 (three individuals), and DHX34 (three individuals). Most identified variants are rare, predicted to be damaging, and occur at conserved amino acid residues. Taken together, these 15 individuals implicate the DExD/H-box helicases in both dominantly and recessively inherited neurodevelopmental phenotypes and highlight the potential for more than one disease mechanism underlying these disorders.

3.
Genet Med ; 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31263215

RESUMO

PURPOSE: Haploinsufficiency of DYRK1A causes a recognizable clinical syndrome. The goal of this paper is to investigate congenital anomalies of the kidney and urinary tract (CAKUT) and genital defects (GD) in patients with DYRK1A variants. METHODS: A large database of clinical exome sequencing (ES) was queried for de novo DYRK1A variants and CAKUT/GD phenotypes were characterized. Xenopus laevis (frog) was chosen as a model organism to assess Dyrk1a's role in renal development. RESULTS: Phenotypic details and variants of 19 patients were compiled after an initial observation that one patient with a de novo pathogenic variant in DYRK1A had GD. CAKUT/GD data were available from 15 patients, 11 of whom presented with CAKUT/GD. Studies in Xenopus embryos demonstrated that knockdown of Dyrk1a, which is expressed in forming nephrons, disrupts the development of segments of embryonic nephrons, which ultimately give rise to the entire genitourinary (GU) tract. These defects could be rescued by coinjecting wild-type human DYRK1A RNA, but not with DYRK1AR205* or DYRK1AL245R RNA. CONCLUSION: Evidence supports routine GU screening of all individuals with de novo DYRK1A pathogenic variants to ensure optimized clinical management. Collectively, the reported clinical data and loss-of-function studies in Xenopus substantiate a novel role for DYRK1A in GU development.

4.
Am J Med Genet A ; 179(5): 803-807, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30848071

RESUMO

Short chain enoyl-CoA hydratase (SCEH) deficiency leads to a severe form of autosomal recessive Leigh syndrome with inevitable neurological decline and early mortality. SCEH is most notably involved in valine catabolism, a deficiency of which results in various metabolic alterations, including increased levels of the highly reactive metabolite 2-methacrylyl-CoA. With no proven treatments available to date, it has been speculated that patients may respond to a valine restricted diet and/or N-acetylcysteine supplementation, as suggested by early studies of a very similar inborn error of metabolism, 3-hydroxyisobutyryl-CoA hydrolase deficiency. We describe a patient with typical Leigh syndrome clinical findings and identified compound heterozygous variants in ECSH1. Valine-restricted diet was initiated at 6 months of age and N-acetylcysteine supplementation at 9 months with subsequent improvement in growth and slow progress in developmental milestones. However, at 15 months, the patient aspirated during a breakthrough seizure from which he did not recover and died soon after from related complications. This report highlights some of the challenges that remain in the management and treatment of SCEH deficiency, while demonstrating that a valine restricted diet and N-acetylcysteine can be safely administered with the potential for clinical improvement.

5.
BMC Nephrol ; 18(1): 243, 2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28720077

RESUMO

BACKGROUND: Hemolytic uremic syndrome (HUS) can occur as a primary process due to mutations in complement genes or secondary to another underlying disease. HUS sometimes occurs in the setting of glomerular diseases, and it has been described in association with Denys-Drash syndrome (DDS), which is characterized by the triad of abnormal genitourinary development; a pathognomonic glomerulopathy, diffuse mesangial sclerosis; and the development of Wilms tumor. CASE PRESENTATION: We report the case of a 46, XX female infant who presented with HUS and biopsy-proven thrombotic microangiopathy. Next generation sequencing of genes with known mutations causative of atypical HUS found that she was homozygous for the Complement Factor H H3 haplotype and heterozygous for a variant of unknown significance in the DGKE gene. Whole exome sequencing identified a de novo heterozygous WT1 c.1384C > T; p.R394W mutation, which is classically associated with Denys-Drash syndrome (DDS). At the time of bilateral nephrectomy five months after her initial biopsy, she had diffuse mesangial sclerosis, typical of Denys-Drash syndrome, without evidence of thrombotic microangiopathy. CONCLUSION: This unique case highlights HUS as a rare but important manifestation of WT1 mutation and provides new insight into the genetics underlying this association.


Assuntos
Síndrome de Denys-Drash/genética , Síndrome Hemolítico-Urêmica/genética , Mutação/genética , Proteínas WT1/genética , Síndrome de Denys-Drash/diagnóstico , Síndrome de Denys-Drash/cirurgia , Diagnóstico Diferencial , Feminino , Síndrome Hemolítico-Urêmica/diagnóstico , Síndrome Hemolítico-Urêmica/cirurgia , Humanos , Lactente
6.
Genet Med ; 19(4): 412-420, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27657687

RESUMO

PURPOSE: To investigate the utility of whole-exome sequencing (WES) to define a molecular diagnosis for patients clinically diagnosed with congenital anomalies of kidney and urinary tract (CAKUT). METHODS: WES was performed in 62 families with CAKUT. WES data were analyzed for single-nucleotide variants (SNVs) in 35 known CAKUT genes, putatively deleterious sequence changes in new candidate genes, and potentially disease-associated copy-number variants (CNVs). RESULTS: In approximately 5% of families, pathogenic SNVs were identified in PAX2, HNF1B, and EYA1. Observed phenotypes in these families expand the current understanding about the role of these genes in CAKUT. Four pathogenic CNVs were also identified using two CNV detection tools. In addition, we found one deleterious de novo SNV in FOXP1 among the 62 families with CAKUT. The clinical database of the Baylor Miraca Genetics laboratory was queried and seven additional unrelated individuals with novel de novo SNVs in FOXP1 were identified. Six of these eight individuals with FOXP1 SNVs have syndromic urinary tract defects, implicating this gene in urinary tract development. CONCLUSION: We conclude that WES can be used to identify molecular etiology (SNVs, CNVs) in a subset of individuals with CAKUT. WES can also help identify novel CAKUT genes.Genet Med 19 4, 412-420.


Assuntos
Variações do Número de Cópias de DNA , Predisposição Genética para Doença/genética , Anormalidades Urogenitais/diagnóstico , Refluxo Vesicoureteral/diagnóstico , Sequenciamento Completo do Exoma/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Fatores de Transcrição Forkhead/genética , Fator 1-beta Nuclear de Hepatócito/genética , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas Nucleares/genética , Fator de Transcrição PAX2/genética , Linhagem , Polimorfismo de Nucleotídeo Único , Proteínas Tirosina Fosfatases/genética , Proteínas Repressoras/genética , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/genética , Adulto Jovem
7.
Cold Spring Harb Mol Case Stud ; 2(6): a001172, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27900362

RESUMO

Using whole-exome sequencing, we have identified novel de novo heterozygous pleckstrin homology domain-interacting protein (PHIP) variants that are predicted to be deleterious, including a frameshift deletion, in two unrelated patients with common clinical features of developmental delay, intellectual disability, anxiety, hypotonia, poor balance, obesity, and dysmorphic features. A nonsense mutation in PHIP has previously been associated with similar clinical features. Patients with microdeletions of 6q14.1, including PHIP, have a similar phenotype of developmental delay, intellectual disability, hypotonia, and obesity, suggesting that the phenotype of our patients is a result of loss-of-function mutations. PHIP produces multiple protein products, such as PHIP1 (also known as DCAF14), PHIP, and NDRP. PHIP1 is one of the multiple substrate receptors of the proteolytic CUL4-DDB1 ubiquitin ligase complex. CUL4B deficiency has been associated with intellectual disability, central obesity, muscle wasting, and dysmorphic features. The overlapping phenotype associated with CUL4B deficiency suggests that PHIP mutations cause disease through disruption of the ubiquitin ligase pathway.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Pré-Escolar , Deficiências do Desenvolvimento/genética , Exoma , Feminino , Mutação da Fase de Leitura , Heterozigoto , Humanos , Deficiência Intelectual/genética , Hipotonia Muscular/genética , Mutação , Obesidade/genética , Fenótipo , Domínios de Homologia à Plecstrina , Sequenciamento Completo do Exoma/métodos
8.
JAMA ; 312(18): 1870-9, 2014 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25326635

RESUMO

IMPORTANCE: Clinical whole-exome sequencing is increasingly used for diagnostic evaluation of patients with suspected genetic disorders. OBJECTIVE: To perform clinical whole-exome sequencing and report (1) the rate of molecular diagnosis among phenotypic groups, (2) the spectrum of genetic alterations contributing to disease, and (3) the prevalence of medically actionable incidental findings such as FBN1 mutations causing Marfan syndrome. DESIGN, SETTING, AND PATIENTS: Observational study of 2000 consecutive patients with clinical whole-exome sequencing analyzed between June 2012 and August 2014. Whole-exome sequencing tests were performed at a clinical genetics laboratory in the United States. Results were reported by clinical molecular geneticists certified by the American Board of Medical Genetics and Genomics. Tests were ordered by the patient's physician. The patients were primarily pediatric (1756 [88%]; mean age, 6 years; 888 females [44%], 1101 males [55%], and 11 fetuses [1% gender unknown]), demonstrating diverse clinical manifestations most often including nervous system dysfunction such as developmental delay. MAIN OUTCOMES AND MEASURES: Whole-exome sequencing diagnosis rate overall and by phenotypic category, mode of inheritance, spectrum of genetic events, and reporting of incidental findings. RESULTS: A molecular diagnosis was reported for 504 patients (25.2%) with 58% of the diagnostic mutations not previously reported. Molecular diagnosis rates for each phenotypic category were 143/526 (27.2%; 95% CI, 23.5%-31.2%) for the neurological group, 282/1147 (24.6%; 95% CI, 22.1%-27.2%) for the neurological plus other organ systems group, 30/83 (36.1%; 95% CI, 26.1%-47.5%) for the specific neurological group, and 49/244 (20.1%; 95% CI, 15.6%-25.8%) for the nonneurological group. The Mendelian disease patterns of the 527 molecular diagnoses included 280 (53.1%) autosomal dominant, 181 (34.3%) autosomal recessive (including 5 with uniparental disomy), 65 (12.3%) X-linked, and 1 (0.2%) mitochondrial. Of 504 patients with a molecular diagnosis, 23 (4.6%) had blended phenotypes resulting from 2 single gene defects. About 30% of the positive cases harbored mutations in disease genes reported since 2011. There were 95 medically actionable incidental findings in genes unrelated to the phenotype but with immediate implications for management in 92 patients (4.6%), including 59 patients (3%) with mutations in genes recommended for reporting by the American College of Medical Genetics and Genomics. CONCLUSIONS AND RELEVANCE: Whole-exome sequencing provided a potential molecular diagnosis for 25% of a large cohort of patients referred for evaluation of suspected genetic conditions, including detection of rare genetic events and new mutations contributing to disease. The yield of whole-exome sequencing may offer advantages over traditional molecular diagnostic approaches in certain patients.


Assuntos
Exoma , Doenças Genéticas Inatas/diagnóstico , Técnicas de Diagnóstico Molecular , Análise de Sequência de DNA/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Feto , Testes Genéticos , Genômica , Humanos , Achados Incidentais , Lactente , Recém-Nascido , Masculino , Mutação , Fenótipo , Encaminhamento e Consulta
9.
N Engl J Med ; 369(16): 1502-11, 2013 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-24088041

RESUMO

BACKGROUND: Whole-exome sequencing is a diagnostic approach for the identification of molecular defects in patients with suspected genetic disorders. METHODS: We developed technical, bioinformatic, interpretive, and validation pipelines for whole-exome sequencing in a certified clinical laboratory to identify sequence variants underlying disease phenotypes in patients. RESULTS: We present data on the first 250 probands for whom referring physicians ordered whole-exome sequencing. Patients presented with a range of phenotypes suggesting potential genetic causes. Approximately 80% were children with neurologic phenotypes. Insurance coverage was similar to that for established genetic tests. We identified 86 mutated alleles that were highly likely to be causative in 62 of the 250 patients, achieving a 25% molecular diagnostic rate (95% confidence interval, 20 to 31). Among the 62 patients, 33 had autosomal dominant disease, 16 had autosomal recessive disease, and 9 had X-linked disease. A total of 4 probands received two nonoverlapping molecular diagnoses, which potentially challenged the clinical diagnosis that had been made on the basis of history and physical examination. A total of 83% of the autosomal dominant mutant alleles and 40% of the X-linked mutant alleles occurred de novo. Recurrent clinical phenotypes occurred in patients with mutations that were highly likely to be causative in the same genes and in different genes responsible for genetically heterogeneous disorders. CONCLUSIONS: Whole-exome sequencing identified the underlying genetic defect in 25% of consecutive patients referred for evaluation of a possible genetic condition. (Funded by the National Human Genome Research Institute.).


Assuntos
Exoma , Doenças Genéticas Inatas/diagnóstico , Testes Genéticos/métodos , Análise de Sequência de DNA/métodos , Adolescente , Criança , Pré-Escolar , Genes Dominantes , Genes Recessivos , Genes Ligados ao Cromossomo X , Doenças Genéticas Inatas/genética , Humanos , Mutação , Fenótipo , Adulto Jovem
10.
Gene ; 499(1): 209-12, 2012 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-22405928

RESUMO

Mutations in POLG account for one of the most frequent nuclear encoded causes of mitochondrial disorders to date. Individuals harboring POLG mutations exhibit fairly heterogeneous clinical presentations leading to increasing difficulties in classifying these patients into defined clinical phenotypes. This study aims to investigate the molecular basis of a mitochondrial cytopathy in a patient with 3-methylglutaconic aciduria and to expand the clinical phenotype associated with POLG mutations. Clinical, molecular and genetic analyses as well as neurophysiological examinations were carried out for a 23-year-old woman of mixed Caucasian and Latin American ancestry with a history of cataracts diagnosed at age 1 year, she had onset of distal muscle weakness at age 2 years progressing to atrophy and ovarian dysgenesis at puberty. The patient was found to have 3-methylglutaconic acid with normal 3 hydroxyisovaleric acid on urine organic acid analysis. POLG sequencing was done and a heterozygous variant, c.2851T>A (p.Y951N) was found which is predicted to be deleterious. There are limited reports of POLG mutations in individuals with 3-methylglutaconic aciduria. This case report of a young woman with a heterozygous mutation in POLG, presenting with muscle weakness and atrophy at a young age aims to aid clinicians in similar challenging diagnostic situations as well as enhances our understanding of POLG-related disease phenotypes.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/genética , Catarata/genética , DNA Polimerase Dirigida por DNA/genética , Debilidade Muscular/genética , Atrofia Muscular/genética , Ovário/anormalidades , Idade de Início , Catarata/complicações , Análise Mutacional de DNA , Polimerase do DNA Mitocondrial , DNA Polimerase Dirigida por DNA/química , Feminino , Glutaratos/metabolismo , Glutaratos/urina , Humanos , Modelos Moleculares , Debilidade Muscular/complicações , Debilidade Muscular/epidemiologia , Atrofia Muscular/complicações , Mutação/fisiologia , Doenças Ovarianas/complicações , Doenças Ovarianas/genética , Adulto Jovem
11.
Nat Genet ; 43(10): 996-1000, 2011 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-21909107

RESUMO

Although thoracic aortic aneurysms and dissections (TAAD) can be inherited as a single-gene disorder, the genetic predisposition in the majority of affected people is poorly understood. In a multistage genome-wide association study (GWAS), we compared 765 individuals who had sporadic TAAD (STAAD) with 874 controls and identified common SNPs at a 15q21.1 locus that were associated with STAAD, with odds ratios of 1.6-1.8 that achieved genome-wide significance. We followed up 107 SNPs associated with STAAD with P < 1 × 10(-5) in the region, in two separate STAAD cohorts. The associated SNPs fall into a large region of linkage disequilibrium encompassing FBN1, which encodes fibrillin-1. FBN1 mutations cause Marfan syndrome, whose major cardiovascular complication is TAAD. This study shows that common genetic variants at 15q21.1 that probably act via FBN1 are associated with STAAD, suggesting a common pathogenesis of aortic disease in Marfan syndrome and STAAD.


Assuntos
Aneurisma da Aorta Torácica/genética , Cromossomos Humanos Par 15/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Proteínas dos Microfilamentos/genética , Aneurisma da Aorta Torácica/patologia , Estudos de Casos e Controles , DNA/genética , DNA/isolamento & purificação , Fibrilina-1 , Fibrilinas , Loci Gênicos , Técnicas de Genotipagem , Humanos , Desequilíbrio de Ligação , Síndrome de Marfan/genética , Proteínas dos Microfilamentos/metabolismo , Mutação , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
12.
Am J Med Genet A ; 155A(5): 1165-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21465659

RESUMO

Juvenile polyposis syndrome (JPS) is caused by heterozygous mutations in either SMAD4 or BMPR1A. Individuals with JPS due to mutations in SMAD4 are at greater risk to manifest signs of hereditary hemorrhagic telangiectasia (HHT). HHT is caused by either mutations in SMAD4 or other genes that modulate transforming growth factor-beta (TGFß) signaling. Additional genes in the TGFß network include FBN1, TGFBR1, and TGFBR2, mutations of which cause either Marfan syndrome (MFS) or Loeys-Dietz syndrome (LDS), respectively. As SMAD4, FBN1, and TGFBR1/2 map to different regions of the genome, disorders associated with mutations in these genes are not expected to co-segregate in a family. We report an individual whose family history was positive for aortopathy, mitral valve dysfunction, and JPS. Mutation analysis of SMAD4 implicates this gene for these phenotypes in this family. Although SMAD4 is among several genes in the TGFß network, and although prior single case reports have described large vessel aneurysms in HHT, this is the first description of aortic and mitral disease presenting with JPS. This observation suggests that, in addition to HHT, individuals with SMAD4 mutations may be at risk for aortic dilation and mitral valve dysfunction. We emphasize the importance of comprehensive review of the medical history prior to molecular testing, especially in an asymptomatic patient.


Assuntos
Aorta/fisiopatologia , Valva Mitral/fisiopatologia , Mutação , Proteína Smad4/genética , Criança , Feminino , Humanos , Polipose Intestinal/congênito , Polipose Intestinal/fisiopatologia , Masculino , Síndromes Neoplásicas Hereditárias , Linhagem
13.
Am J Kidney Dis ; 56(1): 50-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20452711

RESUMO

BACKGROUND: To date, there are no criteria for diagnosing autosomal dominant polycystic kidney disease (ADPKD) in at-risk children 15 years or younger. STUDY DESIGN: Longitudinal (retrospective cohort study). SETTING & PARTICIPANTS: 420 children (mean age, 8.3 +/- 4.2 years) with a family history of ADPKD were studied. MEASUREMENTS: Renal ultrasonography was performed for cyst detection. Urine protein was measured using two 24-hour urine collections. Glomerular filtration rate was calculated using the Schwartz formula. Blood pressure measurements were performed in the arm with the highest blood pressure, using an appropriate cuff size. Standard 2-dimensional and Doppler echocardiography was performed for measuring left ventricular mass index. PREDICTORS: None. OUTCOME: Presence of renal cysts. RESULTS: Renal cysts were detected in 193 children and no cysts were detected in 227 children. In children with renal cysts, 150 had bilateral and 43 had unilateral cysts. Children with bilateral cysts had larger kidneys and more hypertension than children with unilateral or no cysts. Follow-up in 77 children 15 years or younger showed bilateral cysts in 14 and unilateral cysts in 4 of the children who had no detectable renal cysts using ultrasonography at baseline. Similar follow-up of 26 children 15 years or younger with unilateral cysts detected at baseline showed bilateral cysts in 17 children using ultrasonography. By 15 years of age, 181 patients in the total group of 420 showed bilateral cysts. Overall, 193 of 304 children (63.4%) who had follow-up at any age developed bilateral cysts detected using ultrasonography. LIMITATIONS: Follow-up unavailable for all participants. CONCLUSION: The present results in 420 at-risk children with ADPKD 15 years or younger detected bilateral renal cysts using ultrasonography in 181 of the children who had a family history of this genetic disease.


Assuntos
Rim/diagnóstico por imagem , Rim Policístico Autossômico Dominante/diagnóstico por imagem , Fatores Etários , Criança , Estudos de Coortes , Feminino , Seguimentos , Humanos , Rim/metabolismo , Estudos Longitudinais , Masculino , Rim Policístico Autossômico Dominante/urina , Estudos Retrospectivos , Fatores de Risco , Ultrassonografia
14.
J Am Soc Nephrol ; 21(5): 876-83, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20378821

RESUMO

Mutations in the COL4A5 gene cause X-linked Alport syndrome (XLAS). Understanding the correlation between clinical manifestations and the underlying mutations adds prognostic value to genetic testing, which is increasingly available. Our aim was to determine the association between genotype and phenotype in 681 affected male participants with XLAS from 175 US families. Hearing loss and ocular changes were present in 67 and 30% of participants, respectively. Average age of participants at onset of ESRD was 37 years for those with missense mutations, 28 years for those with splice-site mutations, and 25 years for those with truncating mutations (P < 0.0001). We demonstrated a strong relationship between mutation position and age at onset of ESRD, with younger age at onset of ESRD associated with mutations at the 5' end of the gene (hazard ratio 0.766 [95% confidence interval 0.694 to 0.846] per 1000 bp toward the 3' end; P < 0.0001). Affected participants with splice mutations or truncating mutations each had two-fold greater odds of developing eye problems than those with missense mutations; development of hearing impairment showed a similar trend. Hearing loss and ocular changes associated with mutations located closer to the 5; end of the gene. These strong genotype-phenotype correlations could potentially help in the evaluation and counseling of US families with XLAS.


Assuntos
Colágeno Tipo IV/genética , Genótipo , Mutação , Nefrite Hereditária/genética , Fenótipo , Adulto , Idade de Início , Oftalmopatias Hereditárias/genética , Glicina/genética , Perda Auditiva/genética , Humanos , Masculino , Nefrite Hereditária/complicações , Nefrite Hereditária/epidemiologia , Estados Unidos/epidemiologia
15.
Ther Clin Risk Manag ; 4(2): 393-407, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18728845

RESUMO

Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent life- threatening, hereditary disease. ADPKD is more common than sickle cell anemia, cystic fibrosis, muscular dystrophy, hemophilia, Down's syndrome, and Huntington's disease combined. ADPKD is a multisystemic disorder characterized by the progressive development of renal cysts and marked renal enlargement. Structural and functional renal deterioration occurs in ADPKD patients and is the fourth leading cause of end-stage renal disease (ESRD) in adults. Aside from the renal manifestations, extrarenal structural abnormalities, such as liver cysts, cardiovascular abnormalities, and intracranial aneurysms may lead to morbidity and mortality. Recent studies have identified prognostic factors for progressive renal impairment including gender, race, age, proteinuria, hematuria, hypertension and increased left ventricular mass index (LVMI). Early diagnosis and better understanding of the pathophysiology of the disease provides the opportunity to aggressivly treat hypertension with renin-angiotensin-aldosterone system inhibitors and thereby potentially reduce LVMI, prevent cardiovascular morbidity and mortality and slow progression of the renal disease.

16.
Curr Opin Pharmacol ; 6(2): 202-7, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16483846

RESUMO

Body fluid volume regulation by the kidney relies upon the complex interaction of numerous factors. However, in edematous disorders, extrarenal factors can override the 'innate wisdom' of the kidney. For example, in patients with cardiac failure or liver disease and in pregnant women, the normal kidney continues to retain sodium and water despite expanded blood, plasma and extracellular fluid volumes. Such fluid retention can ultimately lead to pulmonary congestion, ascites or peripheral edema. Understanding the kidney's modulation of total body sodium and water in these patients has been perplexing. Cardiac output cannot provide the sole afferent signal for the kidney to regulate sodium and water balance, as the normal kidney can retain excessive amounts of sodium and water when cardiac output is low (e.g. in low output cardiac failure) or high (e.g. cirrhosis or pregnancy). Therefore the integrity of the arterial circulation, which can be impaired either by a low cardiac output or arterial vasodilation, is an important factor in body fluid composition and volume regulation in health and disease.


Assuntos
Baixo Débito Cardíaco/fisiopatologia , Edema/fisiopatologia , Rim/metabolismo , Infarto do Miocárdio/fisiopatologia , Fator Natriurético Atrial/deficiência , Baixo Débito Cardíaco/complicações , Edema/etiologia , Feminino , Humanos , Rim/fisiologia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/terapia , Gravidez , Sódio/metabolismo
17.
BMC Nephrol ; 5: 13, 2004 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-15469615

RESUMO

BACKGROUND: Hepatitis C virus (HCV) infection is a significant problem among patients undergoing maintenance hemodialysis (HD). We conducted a prospective multi-center study to evaluate the effect of dialysis machine separation on the spread of HCV infection. METHODS: Twelve randomly selected dialysis centers in Tehran, Iran were randomly divided into two groups; those using dedicated machines (D) for HCV infected individuals and those using non-dedicated HD machines (ND). 593 HD cases including 51 HCV positive (RT-PCR) cases and 542 HCV negative patients were enrolled in this study. The prevalence of HCV infection in the D group was 10.1% (range: 4.6%- 13.2%) and it was 7.1% (range: 4.2%-16.8%) in the ND group. During the study conduction 5 new HCV positive cases and 169 new HCV negative cases were added. In the D group, PCR positive patients were dialyzed on dedicated machines. In the ND group all patients shared the same machines. RESULTS: In the first follow-up period, the incidence of HCV infection was 1.6% and 4.7% in the D and ND group respectively (p = 0.05). In the second follow-up period, the incidence of HCV infection was 1.3% in the D group and 5.7% in the ND group (p < 0.05). CONCLUSIONS: In this study the incidence of HCV in HD patients decreased by the use of dedicated HD machines for HCV infected patients. Additional studies may help to clarify the role of machine dedication in conjunction with application of universal precautions in reducing HCV transmission.


Assuntos
Infecção Hospitalar/prevenção & controle , Transmissão de Doença Infecciosa/prevenção & controle , Hepatite C/transmissão , Diálise Renal/efeitos adversos , Diálise Renal/instrumentação , Precauções Universais/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Seguimentos , Hepatite C/etiologia , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
18.
Biol Trace Elem Res ; 97(3): 215-24, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14997022

RESUMO

Trace elements have been considered to play critical roles in bone metabolism. This study aims at determining the serum zinc profile and its association with bone mineral density (BMD) abnormalities in thalassemic patients. In 131 transfusion-dependent beta-thalassemic patients, aged 10-20 yr, serum levels of zinc were measured by flame atomic absorption spectrophotometry (F-AAS). BMD values at the lumbar (L1-L4) and femoral neck were determined by dual X-ray absorptiometry (DXA). Dietary zinc intake and daily consumption of calcium were evaluated by a food-frequency questionnaire. Low serum zinc was found in 84.8% (in 44.7% severely low). Below -2 BMD Z-scores were observed in 68.7% and 17.6% of the patients at the lumbar and femoral regions, respectively. Female patients with severe zinc deficiency had lower lumbar BMD Z-scores in comparison to the other females (-3.26 vs -2.54). Serum zinc in females with femoral BMD Z-scores < - 2 was significantly lower by 16.4 microg/dL than other females. Our study suggests that serum levels of zinc can be lowered in the thalassemic patients and partly affect the BMD.


Assuntos
Densidade Óssea , Zinco/sangue , Talassemia beta/sangue , Adolescente , Adulto , Transfusão de Sangue , Densidade Óssea/efeitos dos fármacos , Cálcio/administração & dosagem , Criança , Feminino , Humanos , Masculino , Inquéritos e Questionários , Zinco/administração & dosagem , Zinco/deficiência , Zinco/farmacologia , Talassemia beta/fisiopatologia , Talassemia beta/terapia
19.
Am J Hum Biol ; 16(2): 168-71, 2004 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14994316

RESUMO

The aim of this study was to determine the relationships between bone mineral density (BMD) and blood pressure in 214 men, age 20-76. BMD measurements were done by dual X-ray absorptiometry using a Lunar DPXMD densitometer at the lumbar spine (L2-L4) and different femoral regions. Systolic (SBP) and diastolic (DBP) blood pressure were measured using an MPC-350 sphygmomanometer. Physicians gathered demographic data and participants' dietary intake of calcium were determined by using food frequency questionnaires. After adjusting for age, body mass index, dietary calcium, and exercise history, multiple linear regression models showed that DBP was negatively related to femoral neck BMD (beta = -0.145, P = 0.032) and just shy of significant association with femoral neck BMC (beta = -0.114, P = 0.079). SBP was correlated with femoral neck (r = -0.171, P = 0.012) and Ward's (r = -0.186, P = 0.006) BMD but not after adjusting for possible confounders. Further studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass.


Assuntos
Pressão Sanguínea/fisiologia , Densidade Óssea/fisiologia , Osteoporose/prevenção & controle , Absorciometria de Fóton , Adulto , Idoso , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Risco
20.
BMC Endocr Disord ; 3(1): 4, 2003 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-12914670

RESUMO

ABSTRACT : BACKGROUND : The combination of transfusion and chelation therapy has dramatically extended the life expectancy of thalassemic patients. The main objective of this study is to determine the prevalence of prominent thalassemia complications. METHODS : Two hundred twenty patients entered the study. Physicians collected demographic and anthropometric data and the history of therapies as well as menstrual histories. Patients have been examined to determine their pubertal status. Serum levels of 25(OH) D, calcium, phosphate, iPTH were measured. Thyroid function was assessed by T3, T4 and TSH. Zinc and copper in serum were determined by flame atomic absorption spectrophotometry. Bone mineral density (BMD) measurements at lumbar and femoral regions have been done using dual x-ray absorptiometry. The dietary calcium, zinc and copper intakes were estimated by food-frequency questionnaires. RESULTS : Short stature was seen in 39.3% of our patients. Hypogonadism was seen in 22.9% of boys and 12.2% of girls. Hypoparathyroidism and primary hypothyroidism was present in 7.6% and 7.7% of the patients. About 13 % of patients had more than one endocrine complication with mean serum ferritin of 1678 +/- 955 micrograms/lit. Prevalence of lumbar osteoporosis and osteopenia were 50.7% and 39.4%. Femoral osteoporosis and osteopenia were present in 10.8% and 36.9% of the patients. Lumbar BMD abnormalities were associated with duration of chelation therapy. Low serum zinc and copper was observed in 79.6% and 68% of the study population respectively. Serum zinc showed significant association with lumbar but not femoral BMD. In 37.2% of patients serum levels of 25(OH) D below 23 nmol/l were detected. CONCLUSION : High prevalence of complications among our thalassemics signifies the importance of more detailed studies along with therapeutic interventions.

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