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1.
iScience ; 26(6): 106818, 2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37235056

RESUMEN

Autoimmune polyendocrine syndrome type 1 (APS-1) is an autosomal recessive disease characterized by severe and childhood onset organ-specific autoimmunity caused by mutations in the autoimmune regulator (AIRE) gene. More recently, dominant-negative mutations within the PHD1, PHD2, and SAND domains have been associated with an incompletely penetrant milder phenotype with later onset familial clustering, often masquerading as organ-specific autoimmunity. Patients with immunodeficiencies or autoimmunity where genetic analyses revealed heterozygous AIRE mutations were included in the study and the dominant-negative effects of the AIRE mutations were functionally assessed in vitro. We here report additional families with phenotypes ranging from immunodeficiency, enteropathy, and vitiligo to asymptomatic carrier status. APS-1-specific autoantibodies can hint to the presence of these pathogenic AIRE variants although their absence does not rule out their presence. Our findings suggest functional studies of heterozygous AIRE variants and close follow-up of identified individuals and their families.

2.
Mol Genet Metab Rep ; 33: 100931, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36420423

RESUMEN

Malate dehydrogenases (MDH) serve a critical role in maintaining equilibrium of the NAD+/NADH ratio between the mitochondria and cytosol through the catalysis of the oxidation of L-malate to oxaloacetate in a reversible, NADH-dependent manner. MDH2 encodes the mitochondrial isoform, which is integral to the tricarboxylic acid cycle and thus energy homeostasis. Recently, five patients harboring compound heterozygous MDH2 variants have been described, three with early-onset epileptic encephalopathy, one with a stroke-like episode, and one with dilated cardiomyopathy. Here, we describe an additional seven patients with biallelic variants in MDH2, the largest and most neurodevelopmentally and ethnically diverse cohort to-date, including homozygous variants, a sibling pair, non-European patients, and an adult. From these patients, we learn that MDH2 deficiency results in a biochemical signature including elevations of plasma lactate and the lactate:pyruvate ratio with urinary excretion of malate. It also results in a recognizable constellation of neuroimaging findings of anterior-predominant cerebral atrophy, subependymal cysts with ventricular septations. We also recognize MDH2 deficiency as a cause of Leigh syndrome. Taken with existing patient reports, we conclude that MDH2 deficiency is an emerging and likely under-recognized cause of infantile epileptic encephalopathy and provide a framework for medical evaluation of patients identified with biallelic MDH2 variants.

3.
J Pers Med ; 11(6)2021 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-34208188

RESUMEN

Ovarian cancer (OVCA) patients may carry genes conferring cancer risk to biological family; however, fewer than one-quarter of patients receive genetic testing. "Traceback" cascade testing -outreach to potential probands and relatives-is a possible solution. This paper outlines a funded study (U01 CA240747-01A1) seeking to determine a Traceback program's feasibility, acceptability, effectiveness, and costs. This is a multisite prospective observational feasibility study across three integrated health systems. Informed by the Conceptual Model for Implementation Research, we will outline, implement, and evaluate the outcomes of an OVCA Traceback program. We will use standard legal research methodology to review genetic privacy statutes; engage key stakeholders in qualitative interviews to design communication strategies; employ descriptive statistics and regression analyses to evaluate the site differences in genetic testing and the OVCA Traceback testing; and assess program outcomes at the proband, family member, provider, system, and population levels. This study aims to determine a Traceback program's feasibility and acceptability in a real-world context. It will account for the myriad factors affecting implementation, including legal issues, organizational- and individual-level barriers and facilitators, communication issues, and program costs. Project results will inform how health care providers and systems can develop effective, practical, and sustainable Traceback programs.

4.
Epilepsia ; 62(7): e103-e109, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34041744

RESUMEN

CSNK2B has recently been implicated as a disease gene for neurodevelopmental disability (NDD) and epilepsy. Information about developmental outcomes has been limited by the young age and short follow-up for many of the previously reported cases, and further delineation of the spectrum of associated phenotypes is needed. We present 25 new patients with variants in CSNK2B and refine the associated NDD and epilepsy phenotypes. CSNK2B variants were identified by research or clinical exome sequencing, and investigators from different centers were connected via GeneMatcher. Most individuals had developmental delay and generalized epilepsy with onset in the first 2 years. However, we found a broad spectrum of phenotypic severity, ranging from early normal development with pharmacoresponsive seizures to profound intellectual disability with intractable epilepsy and recurrent refractory status epilepticus. These findings suggest that CSNK2B should be considered in the diagnostic evaluation of patients with a broad range of NDD with treatable or intractable seizures.


Asunto(s)
Discapacidades del Desarrollo/genética , Epilepsia Generalizada/genética , Adolescente , Adulto , Edad de Inicio , Niño , Preescolar , Discapacidades del Desarrollo/fisiopatología , Epilepsias Mioclónicas/diagnóstico , Epilepsias Mioclónicas/etiología , Epilepsias Mioclónicas/genética , Epilepsia Generalizada/diagnóstico , Epilepsia Generalizada/etiología , Exoma/genética , Femenino , Variación Genética , Humanos , Lactante , Discapacidad Intelectual/etiología , Discapacidad Intelectual/genética , Masculino , Mutación/genética , Fenotipo , Estado Epiléptico/diagnóstico , Estado Epiléptico/etiología , Estado Epiléptico/genética , Adulto Joven
5.
JCO Oncol Pract ; 17(4): e575-e581, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33428469

RESUMEN

PURPOSE: Current US guidelines recommend more intensive breast cancer screening and preventive strategies for patients at more than 20% lifetime risk for breast and ovarian cancer (high risk for breast and ovarian cancer [HRBOC]). Guidelines recommend that yearly mammograms alternating with magnetic resonance imaging (MRI) screening should be considered as early as 30 years old. Furthermore, BRCA mutation carriers should consider bilateral mastectomy and bilateral oophorectomy after age 35. It was unclear what the uptake of screening and risk-reducing strategies were for patients who were cancer-free and cancer survivors seen by Kaiser Permanente Mid-Atlantic States (KPMAS) Genetics. METHODS: We retrospectively studied female patients (members of KPMAS between 2005 and 2016) diagnosed as HRBOC and/or tested for breast cancer-related mutations by KPMAS Genetics during 2013-2016. We identified cancer diagnoses, mammogram and breast MRI screening, mastectomies, and oophorectomies that occurred before and after the Genetics visit during the study period. RESULTS: Our cohort included 813 women with a HRBOC diagnosis, with a median 51 years of age at diagnosis, 45% White, 38% Black, and 15% other ethnicity. Most cancers occurred prior to the Genetics visit: 513/527 breast cancer diagnoses and 55/57 ovarian cancer diagnoses. Fewer than five prophylactic mastectomies and 89 prophylactic oophorectomies were identified. Among 228 patients who were 30-75 years old, breast cancer-free at the time of HRBOC diagnosis, and members for over 6 months, 190 (83%) had at least one screening test (mammogram or MRI) after the consultation with Genetic, but 79% never had an MRI before or after the consultation. CONCLUSION: Our findings suggest that earlier detection of patients with HRBOC and closer monitoring is needed.


Asunto(s)
Neoplasias de la Mama , Adulto , Anciano , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/genética , Neoplasias de la Mama/prevención & control , Detección Precoz del Cáncer , Femenino , Genes BRCA1 , Genes BRCA2 , Humanos , Mastectomía , Persona de Mediana Edad , Estudios Retrospectivos
6.
J Clin Invest ; 131(6)2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33497358

RESUMEN

Hirschsprung disease (HSCR) is the most frequent developmental anomaly of the enteric nervous system, with an incidence of 1 in 5000 live births. Chronic intestinal pseudo-obstruction (CIPO) is less frequent and classified as neurogenic or myogenic. Isolated HSCR has an oligogenic inheritance with RET as the major disease-causing gene, while CIPO is genetically heterogeneous, caused by mutations in smooth muscle-specific genes. Here, we describe a series of patients with developmental disorders including gastrointestinal dysmotility, and investigate the underlying molecular bases. Trio-exome sequencing led to the identification of biallelic variants in ERBB3 and ERBB2 in 8 individuals variably associating HSCR, CIPO, peripheral neuropathy, and arthrogryposis. Thorough gut histology revealed aganglionosis, hypoganglionosis, and intestinal smooth muscle abnormalities. The cell type-specific ErbB3 and ErbB2 function was further analyzed in mouse single-cell RNA sequencing data and in a conditional ErbB3-deficient mouse model, revealing a primary role for ERBB3 in enteric progenitors. The consequences of the identified variants were evaluated using quantitative real-time PCR (RT-qPCR) on patient-derived fibroblasts or immunoblot assays on Neuro-2a cells overexpressing WT or mutant proteins, revealing either decreased expression or altered phosphorylation of the mutant receptors. Our results demonstrate that dysregulation of ERBB3 or ERBB2 leads to a broad spectrum of developmental anomalies, including intestinal dysmotility.


Asunto(s)
Discapacidades del Desarrollo/genética , Seudoobstrucción Intestinal/genética , Mutación , Neurregulina-1/genética , Receptor ErbB-2/genética , Receptor ErbB-3/genética , Adolescente , Animales , Preescolar , Discapacidades del Desarrollo/patología , Modelos Animales de Enfermedad , Femenino , Motilidad Gastrointestinal/genética , Enfermedad de Hirschsprung/genética , Enfermedad de Hirschsprung/patología , Humanos , Recién Nacido , Seudoobstrucción Intestinal/patología , Masculino , Ratones , Modelos Moleculares , Linaje , Fenotipo , Embarazo , Receptor ErbB-2/química , Receptor ErbB-3/química , Receptor ErbB-3/deficiencia
7.
J Pers Med ; 9(4)2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31683813

RESUMEN

Health systems and physicians nationwide aspire to consistently and reliably apply genetic and genomic information to guide disease prevention, management, and treatment. However, clinical information, including genetics/genomics data from within and outside of the care delivery system, is expanding rapidly. Between November 2017 and April 2018, we surveyed 1502 Permanente Medical Group primary care and specialist physicians to assess the degree to which direct-to-consumer genetic test results were being presented to physicians and identify genetics educational needs among physicians (response rate 15%). Adjusted logistic regression (according to respondent characteristics) was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) comparing responses within groups. Results showed 35% and 12% of respondents reported receiving at least one direct-to-consumer health risk genetic result (DTC-health risk) or direct-to-consumer pharmacogenomic test result (DTC-PGx), respectively, from a patient in the past year. Of those receiving at least one test result, 40% (DTC-health risk) and 39% (DTC-PGx) of physicians reported 1+ referral(s); 78% (DTC-health risk) and 42% (DTC-PGx) of referrals were to clinical genetics. In total, 85% of physicians would spend ≥2 h/year on genetics/genomics education.

8.
PLoS Biol ; 17(4): e3000194, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30973865

RESUMEN

Adult-onset hearing loss is very common, but we know little about the underlying molecular pathogenesis impeding the development of therapies. We took a genetic approach to identify new molecules involved in hearing loss by screening a large cohort of newly generated mouse mutants using a sensitive electrophysiological test, the auditory brainstem response (ABR). We review here the findings from this screen. Thirty-eight unexpected genes associated with raised thresholds were detected from our unbiased sample of 1,211 genes tested, suggesting extreme genetic heterogeneity. A wide range of auditory pathophysiologies was found, and some mutant lines showed normal development followed by deterioration of responses, revealing new molecular pathways involved in progressive hearing loss. Several of the genes were associated with the range of hearing thresholds in the human population and one, SPNS2, was involved in childhood deafness. The new pathways required for maintenance of hearing discovered by this screen present new therapeutic opportunities.


Asunto(s)
Percepción Auditiva/genética , Potenciales Evocados Auditivos del Tronco Encefálico/genética , Pérdida Auditiva/genética , Estimulación Acústica/métodos , Adulto , Animales , Proteínas de Transporte de Anión/genética , Niño , Fenómenos Electrofisiológicos/genética , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Femenino , Estudios de Asociación Genética , Audición/genética , Pérdida Auditiva/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL
9.
Prog Mol Biol Transl Sci ; 128: 103-37, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25410543

RESUMEN

Major depressive disorder (MDD) is a leading cause of disability worldwide and is associated with poor psychological, medical, and socioeconomic outcomes. Although much has been learned about the etiology and treatment options of MDD over the past decade, there remain unanswered questions that pose challenges to improving acute and chronic outcomes for those with MDD. MDD is a clinically heterogeneous disorder. Genetic studies to date have indicated a number of genes, including transporters, neurotransmitters, neurotrophins, and their associated signaling networks that may predispose individuals to MDD and may also predict treatment outcomes. However, twin studies indicate that genes account for only a small degree of the variation in MDD. Thus, other mechanisms, through epigenetic marks, may act to form a molecular memory of previous gene-to-environment interactions and to establish vulnerabilities (or, conversely, resistance) to MDD. Current evidence supports a role for pre-, peri-, and early postnatal adversities and stressful life events into adulthood affecting epigenetic patterns, providing a mechanistic foundation to develop epigenetic marks as biomarkers for MDD. This review presents the evidence supporting a role for epigenetic effects in MDD and in treatment response. We also discuss the controversy behind modulating epigenetic mechanisms in long-term antidepressant pharmacotherapy.


Asunto(s)
Trastorno Depresivo Mayor/genética , Epigénesis Genética , Secuencia de Bases , Estudios de Asociación Genética , Humanos , Datos de Secuencia Molecular
10.
Nat Genet ; 46(2): 182-7, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24362817

RESUMEN

Constitutional SMARCB1 mutations at 22q11.23 have been found in ∼50% of familial and <10% of sporadic schwannomatosis cases. We sequenced highly conserved regions along 22q from eight individuals with schwannomatosis whose schwannomas involved somatic loss of one copy of 22q, encompassing SMARCB1 and NF2, with a different somatic mutation of the other NF2 allele in every schwannoma but no mutation of the remaining SMARCB1 allele in blood and tumor samples. LZTR1 germline mutations were identified in seven of the eight cases. LZTR1 sequencing in 12 further cases with the same molecular signature identified 9 additional germline mutations. Loss of heterozygosity with retention of an LZTR1 mutation was present in all 25 schwannomas studied. Mutations segregated with disease in all available affected first-degree relatives, although four asymptomatic parents also carried an LZTR1 mutation. Our findings identify LZTR1 as a gene predisposing to an autosomal dominant inherited disorder of multiple schwannomas in ∼80% of 22q-related schwannomatosis cases lacking mutation in SMARCB1.


Asunto(s)
Cromosomas Humanos Par 22/genética , Predisposición Genética a la Enfermedad/genética , Mutación de Línea Germinal/genética , Modelos Moleculares , Neurilemoma/genética , Conformación Proteica , Factores de Transcripción/genética , Secuencia de Bases , Proteínas Cromosómicas no Histona/genética , ADN Complementario/genética , Proteínas de Unión al ADN/genética , Componentes del Gen , Genes Dominantes/genética , Humanos , Pérdida de Heterocigocidad , Repeticiones de Microsatélite/genética , Datos de Secuencia Molecular , Neurofibromatosis 2/genética , Linaje , Proteína SMARCB1 , Análisis de Secuencia de ADN , Factores de Transcripción/química
11.
Am J Med Genet A ; 161A(8): 1833-52, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23813913

RESUMEN

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.


Asunto(s)
1-Alquil-2-acetilglicerofosfocolina Esterasa/genética , Proteínas 14-3-3/genética , Encéfalo/anomalías , Trastornos de la Conducta Infantil/patología , Trastornos Generalizados del Desarrollo Infantil/patología , Cromosomas Humanos Par 17/genética , Duplicación de Gen , Proteínas Asociadas a Microtúbulos/genética , Adolescente , Adulto , Encéfalo/patología , Niño , Trastornos de la Conducta Infantil/genética , Trastornos Generalizados del Desarrollo Infantil/genética , Preescolar , Femenino , Humanos , Lactante , Masculino , Fenotipo
12.
BMC Gastroenterol ; 12: 141, 2012 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-23067347

RESUMEN

BACKGROUND: The most common causes of cholestatic jaundice are biliary atresia and idiopathic neonatal hepatitis (INH). Specific disorders underlying INH, such as various infectious and metabolic causes, including neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) especially, in East Asian populations are increasingly being identified. Since most NICCD infants recovered from liver disease by 1 year of age, they often are misdiagnosed with INH, leading to difficulty in determining the true prevalence of NICCD. Mutation(s) of human SLC25A13 gene encoding a mitochondrial aspartate/glutamate carrier isoform 2 (AGC2), can lead to AGC2 deficiency, resulting in NICCD and an adult-onset fatal disease namely citrullinemia type II (CTLN2). To study the prevalence of NICCD and SLC25A13 mutations in Thai infants, and to compare manifestations of NICCD and non-NICCD, infants with idiopathic cholestatic jaundice or INH were enrolled. Clinical and biochemical data were reviewed. Urine organic acid and plasma amino acids profiles were analyzed. PCR-sequencing of all 18 exons of SLC25A13 and gap PCR for the mutations IVS16ins3kb and Ex16+74_IVS17-32del516 were performed. mRNA were analyzed in selected cases with possible splicing error. RESULTS: Five out of 39 (12.8%) unrelated infants enrolled in the study were found to have NICCD, of which three had homozygous 851del4 (GTATdel) and two compound heterozygous 851del4/IVS16ins3kb and 851del4/1638ins23, respectively. Two missense mutations (p.M1? and p.R605Q) of unknown functional significance were identified. At the initial presentation, NICCD patients had higher levels of alkaline phosphatase (ALP) and alpha-fetoprotein (AFP) and lower level of alanine aminotransferase (ALT) than those in non-NICCD patients (p< 0.05). NICCD patients showed higher citrulline level and threonine/serine ratio than non-NICCD infants (p< 0.05). Fatty liver was found in 2 NICCD patients. Jaundice resolved in all NICCD and in 87.5% of non-NICCD infants at the median age of 9.5 and 4.0 months, respectively. CONCLUSION: NICCD should be considered in infants with idiopathic cholestasis. The preliminary estimated prevalence of NICCD was calculated to be 1/48,228 with carrier rate of 1/110 among Thai infants. However, this number may be underestimated and required further analysis with mutation screening in larger control population to establish the true prevalence of NICCD and AGC2 deficiency.


Asunto(s)
Pueblo Asiatico/genética , Citrulinemia/epidemiología , Citrulinemia/genética , Proteínas de Transporte de Membrana Mitocondrial/genética , Mutación/genética , Edad de Inicio , Aminoácidos/sangre , Pueblo Asiatico/estadística & datos numéricos , Secuencia de Bases , Ácidos Carboxílicos/orina , Exones , Hígado Graso/diagnóstico , Hígado Graso/epidemiología , Hígado Graso/genética , Femenino , Humanos , Lactante , Intrones , Masculino , Datos de Secuencia Molecular , Prevalencia , Análisis de Secuencia de ADN
13.
Mol Genet Metab ; 106(4): 439-41, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22658692

RESUMEN

INTRODUCTION: 3-Methyl CoA carboxylase (3-MCC) deficiency is an inborn error of metabolism in the catabolism of the amino acid leucine. Original reports suggested this disorder was associated with significant neurological and biochemical effects. However newborn screening has identified a higher than expected incidence of this disorder with apparent normal outcome in most cases. METHOD: A retrospective analysis of thirty-five cases of 3-MCC deficiency identified by newborn screening and diagnosed by enzyme or molecular analysis. RESULTS: There was a strong inverse correlation between initial C5OH level and residual enzyme activity. A few reports of hypoglycemia, ketosis, poor feeding/failure to thrive or fasting intolerance were reported, but there was no clear relationship between symptoms and residual enzyme activity. Developmental outcome included several children with mental retardation (including one with Down syndrome and one with schizencephaly) and two with Autism Spectrum disorders but there was no apparent relationship to residual enzyme activity. Free carnitine deficiency was relatively common. DISCUSSION: Although residual enzyme activity was clearly related to metabolite elevation, there was no apparent relationship with other measures of outcome. The number of reports of neurologic abnormalities or metabolic symptoms (poor feeding, hypoglycemia, fasting intolerance, etc.) is concerning, but the significance is unclear in this retrospective sample.


Asunto(s)
Ligasas de Carbono-Carbono/deficiencia , Tamizaje Neonatal/métodos , Trastornos Innatos del Ciclo de la Urea/diagnóstico , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Trastornos Innatos del Ciclo de la Urea/enzimología
14.
Mol Genet Metab ; 105(2): 198-202, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22100375

RESUMEN

Alkaptonuria is a rare metabolic disorder of tyrosine catabolism in which homogentisic acid (HGA) accumulates and is deposited throughout the spine, large joints, cardiovascular system, and various tissues throughout the body. In the cardiovascular system, pigment deposition has been described in the heart valves, endocardium, pericardium, aortic intima and coronary arteries. The prevalence of cardiovascular disease in patients with alkaptonuria varies in previous reports. We present a series of 76 consecutive adult patients with alkaptonuria who underwent transthoracic echocardiography between 2000 and 2009. A subgroup of 40 patients enrolled in a treatment study underwent non-contrast CT scans and these were assessed for vascular calcifications. Six of the 76 patients had aortic valve replacement. In the remaining 70 patients, 12 patients had aortic sclerosis and 7 patients had aortic stenosis. Unlike degenerative aortic valve disease, we found no correlation with standard cardiac risk factors. There was a modest association between the severity of aortic valve disease and joint involvement, however, we saw no correlation with urine HGA levels. Vascular calcifications were seen in the coronaries, cardiac valves, aortic root, descending aorta and iliac arteries. These findings suggest an important role for echocardiographic screening of alkaptonuria patients to detect valvular heart disease and cardiac CT to detect coronary artery calcifications.


Asunto(s)
Alcaptonuria/metabolismo , Alcaptonuria/patología , Estenosis de la Válvula Aórtica/patología , Sistema Cardiovascular/patología , Ácido Homogentísico/metabolismo , Tirosina/metabolismo , Calcificación Vascular/patología , Adulto , Anciano , Anciano de 80 o más Años , Alcaptonuria/complicaciones , Alcaptonuria/epidemiología , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/epidemiología , Ecocardiografía , Femenino , Ácido Homogentísico/orina , Humanos , Masculino , Persona de Mediana Edad , Pigmentos Biológicos/metabolismo , Tirosina/genética , Calcificación Vascular/complicaciones , Calcificación Vascular/epidemiología , Adulto Joven
15.
Mol Genet Metab ; 103(4): 307-14, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21620748

RESUMEN

Alkaptonuria is a rare, autosomal recessive disorder of tyrosine degradation due to deficiency of the third enzyme in the catabolic pathway. As a result, homogentisic acid (HGA) accumulates and is excreted in gram quantities in the urine, which turns dark upon alkalization. The first symptoms, occurring in early adulthood, involve a painful, progressively debilitating arthritis of the spine and large joints. Cardiac valvular disease and renal and prostate stones occur later. Previously suggested therapies have failed to show benefit, and management remains symptomatic. Nitisinone, a potent inhibitor of the second enzyme in the tyrosine catabolic pathway, is considered a potential therapy; proof-of-principle studies showed 95% reduction in urinary HGA. Based on those findings, a prospective, randomized clinical trial was initiated in 2005 to evaluate 40 patients over a 36-month period. The primary outcome parameter was hip total range of motion with measures of musculoskeletal function serving as secondary parameters. Biochemically, this study consistently demonstrated 95% reduction of HGA in urine and plasma over the course of 3 years. Clinically, primary and secondary parameters did not prove benefit from the medication. Side effects were infrequent. This trial illustrates the remarkable tolerability of nitisinone, its biochemical efficacy, and the need to investigate its use in younger individuals prior to development of debilitating arthritis.


Asunto(s)
4-Hidroxifenilpiruvato Dioxigenasa/antagonistas & inhibidores , Alcaptonuria/tratamiento farmacológico , Ciclohexanonas/uso terapéutico , Nitrobenzoatos/uso terapéutico , Adulto , Alcaptonuria/sangre , Alcaptonuria/orina , Ácido Homogentísico/sangre , Ácido Homogentísico/orina , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Tirosina/metabolismo
16.
Hum Mutat ; 30(12): 1611-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19862842

RESUMEN

Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder, characterized by accumulation of homogentisic acid, leading to darkened urine, pigmentation of connective tissue (ochronosis), joint and spine arthritis, and destruction of cardiac valves. AKU is due to mutations in the homogentisate dioxygenase gene (HGD) that converts homogentisic acid to maleylacetoacetic acid in the tyrosine catabolic pathway. Here we report a comprehensive mutation analysis of 93 patients enrolled in our study, as well as an extensive update of all previously published HGD mutations associated with AKU. Within our patient cohort, we identified 52 HGD variants, of which 22 were novel. This yields a total of 91 identified HGD variations associated with AKU to date, including 62 missense, 13 splice site, 10 frameshift, 5 nonsense, and 1 no-stop mutation. Most HGD variants reside in exons 3, 6, 8, and 13. We assessed the potential effect of all missense variations on protein function, using five bioinformatic tools specifically designed for interpretation of missense variants (SIFT, POLYPHEN, PANTHER, PMUT, and SNAP). We also analyzed the potential effect of splice-site variants using two different tools (BDGP and NetGene2). This study provides valuable resources for molecular analysis of alkaptonuria and expands our knowledge of the molecular basis of this disease.


Asunto(s)
Alcaptonuria/enzimología , Alcaptonuria/genética , Homogentisato 1,2-Dioxigenasa/genética , Mutación/genética , Alcaptonuria/diagnóstico por imagen , Alcaptonuria/patología , Estudios de Cohortes , Exones/genética , Genotipo , Homogentisato 1,2-Dioxigenasa/orina , Ácido Homogentísico/orina , Humanos , National Institutes of Health (U.S.) , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Radiografía , Hermanos , Estados Unidos
17.
J Pediatr Hematol Oncol ; 31(10): 768-70, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20051935

RESUMEN

The authors reported a 14-year-old boy who presented with multiple organs thrombosis and subluxation of lens. His diagnosis of homocystinuria was delayed owing to the unrecognition of the disease resulting in significant morbidity. The mutation analysis showed one novel mutation that can explain the high level of plasma homocysteine.


Asunto(s)
Cistationina betasintasa/genética , Homocistinuria/genética , Mutación , Adolescente , Análisis Mutacional de ADN , Humanos , Masculino , Tailandia , Trombosis/etiología
19.
J Rheumatol ; 33(11): 2280-5, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16981292

RESUMEN

OBJECTIVE: To describe the musculoskeletal (MSK) findings in patients with alkaptonuria and to show which of these factors are associated with disability in this population. METHODS: This is a prospective cross-sectional MSK assessment of subjects. Participants included 53 patients with alkaptonuria across the life span, 22 female and 31 male, mean age 43.6 years (10-80 yrs), participating in a natural history study supported by the National Human Genome Research Institute (NHGRI). Assessments included objective measures of the MSK system (range of motion, radiographic assessment of joints and spine, etc.) and questionnaires including the Human Activity Profile (HAP), Health Assessment Questionnaire (HAQ), SF-36 health survey, and the Fatigue Assessment Instrument. RESULTS: There were 18 patients with kyphosis, 16 with scoliosis, 16 with marked reduction in range of motion of at least one major joint, 15 with joint replacements of major joints, 11 with tendon ruptures. A positive Schober's test was highly correlated with substantial functional loss and associated with disability as measured by the HAP (p < or = 0.0001), HAQ (p < or = 0.0001), and the physical component summary (p < or = 0.0001) of the SF-36 health survey. Severity of lumbar spine involvement had the greatest correlation with disability measures (p < or = 0.0001). All objective and subjective physical measures worsened with age. CONCLUSION: Disability is common and severe in patients with alkaptonuria and correlates well with physical findings. Disability does not correlate with self-reports of mental competencies. Aging with alkaptonuria is associated with progressive disability.


Asunto(s)
Alcaptonuria/complicaciones , Alcaptonuria/fisiopatología , Personas con Discapacidad , Enfermedades Musculoesqueléticas/etiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Artroplastia/estadística & datos numéricos , Niño , Estudios Transversales , Evaluación de la Discapacidad , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculoesqueléticas/rehabilitación , Estudios Prospectivos , Rango del Movimiento Articular/fisiología , Índice de Severidad de la Enfermedad
20.
Metabolism ; 54(6): 719-28, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15931605

RESUMEN

Alkaptonuria, a rare autosomal recessive disorder caused by mutations in the HGD gene and deficiency of homogentisate 1,2 dioxygenase, is characterized by ochronosis, arthritis, and daily excretion of gram quantities of homogentisic acid (HGA). Nitisinone, an inhibitor of the enzyme 4-hydroxyphenylpyruvate dioxygenase, can drastically reduce urinary excretion of HGA in individuals with alkaptonuria. We investigated the safety and the HGA-depleting efficacy of nitisinone in an open-label, single-center study of 9 alkaptonuria patients (5 women, 4 men; 35-69 years of age) over the course of 3 to 4 months. Each patient received nitisinone in incremental doses, 0.35 mg bid followed by 1.05 mg bid, and remained on this dosage and a regular diet for 3 months. Nitisinone reduced urinary HGA levels from an average of 4.0 +/- 1.8 (SD) g/day to 0.2 +/- 0.2 g/day ( P < .001). The average plasma tyrosine concentration, initially 68 +/- 18 mmicro mol/L, rose to 760 +/- 181 micro mol/L ( P < .001). During the final week of the study, 5 patients adhered to a protein-restricted diet (40 g/day), and their mean plasma tyrosine level fell from 755 +/- 167 to 603 +/- 114 mu mol/L. Six of the 7 patients who received nitisinone for more than 1 week reported decreased pain in their affected joints. Weekly ophthalmologic examinations showed no signs of corneal toxicity. Adverse events included the passing of kidney stones, the recognition of symptoms related to aortic stenosis, and elevation of liver transaminase levels. We conclude that low-dose nitisinone effectively reduced urinary HGA levels in patients with alkaptonuria. Future long-term clinical trials are planned to determine the benefits of nitisinone in preventing joint deterioration and providing pain relief, and its long-term side effects.


Asunto(s)
Alcaptonuria/tratamiento farmacológico , Ciclohexanonas/uso terapéutico , Nitrobenzoatos/uso terapéutico , Adulto , Anciano , Alcaptonuria/metabolismo , Ciclohexanonas/efectos adversos , Ciclohexanonas/sangre , Proteínas en la Dieta/administración & dosificación , Femenino , Ácido Homogentísico/sangre , Ácido Homogentísico/orina , Humanos , Masculino , Persona de Mediana Edad , Nitrobenzoatos/efectos adversos , Nitrobenzoatos/sangre , Tirosina/sangre
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