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BACKGROUND: An association between hearing impairment (HI) and congenital hypothyroidism (CH) has been reported previously. However, in general, studies were retrospective and had small sample sizes, and the results were variable and inconclusive. The aim of our study was to assess the prevalence of HI among patients with CH and to examine factors potentially predictive of HI including severity of CH, etiology of CH, and timing of treatment initiation. METHODS: Audiometry was undertaken prospectively in 66 patients aged 3-21 years diagnosed with primary CH and 49 healthy matched controls. All patients with HI underwent examination by an otolaryngologist, and in patients with sensorineural loss, brainstem evoked response audiometry was performed. A next-generation sequencing (NGS) panel for genes involved in deafness was performed in patients with sensorineural HI to exclude additional genetic etiologies. RESULTS: HI was found in 19 patients (28.7%). Among them, 5 (7.6%) had moderate to severe bilateral sensorineural impairment and 14 (21.2%) had mild conductive HI. Conductive HI was bilateral in 5 of these patients (36%). None of the controls had HI. No specific etiology was found in patients with HI, and no differences were identified in age at diagnosis, age at initiation of levothyroxine (LT4) therapy, gender, or ethnicity between patients with and without HI. A nonsignificant trend toward lower mean screening TT4 levels was found in patients with HI (compared to those without HI) (3.42 vs. 5.34 µg/dL, p = 0.095). No pathogenic variants in genes attributed to HI were identified by NGS in the 5 patients with sensorineural deafness, indicating that HI in these patients was likely attributable to CH rather than other genetic etiologies. CONCLUSIONS: Our findings indicate a high prevalence of HI among patients with CH, predominantly of the conductive type. HI was not associated with the etiology of CH or with delayed initiation of LT4 therapy. Audiometry is recommended for children diagnosed with CH and repeat monitoring may be warranted to identify acquired HI and to prevent long-term sequelae of undiagnosed deafness.
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Ververi-Brady syndrome (VBS), first reported in 2018, is characterized by intellectual disability, speech delay, and mild dysmorphic facial features. VBS has been linked to de novo loss-of-function variants in the glutamine-rich protein 1 (QRICH1) on chromosome 3p21 and was reported until lately in only five individuals. Four additional cases have just been described substantiating the notion that children with VBS are mildly dysmorphic, mildly to moderately intellectually disabled, have linear growth shortage, are picky eaters, and have notable attention and social behavioral deficits. We describe a new patient and review the clinical and genetic information, on all previously reported VBS cases. The child here reported is noted for maladaptive behavior, sensory hypersensitivity, and slow linear growth. He is mainly hyperactive, distractible, impulsive, and inattentive. His speech, initially delayed, is fair and his verbal comprehension age adequate.
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Proteínas de Ligação a DNA/genética , Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/genética , Fatores de Transcrição/genética , Criança , Pré-Escolar , Cromossomos Humanos Par 3/genética , Deficiências do Desenvolvimento/patologia , Feminino , Humanos , Lactente , Deficiência Intelectual/patologia , Transtornos do Desenvolvimento da Linguagem/patologia , Mutação com Perda de Função/genética , Masculino , FenótipoRESUMO
Background: POU1F1 is an essential transcription factor for the differentiation, proliferation and survival of somatotrophs, lactotrophs, and thyrotrophs. Mutations in the POU1F1 gene are characterized by growth hormone (GH), thyrotropin, and prolactin deficiencies, commonly presenting with growth retardation and central hypothyroidism. Since the first report in 1992, more than 25 mutations have been identified in POU1F1. Case Description: We describe a 17-year-old male who presented to our Pediatric Endocrinology clinic with extreme short stature (height 81.7 cm, -9.3 SD), cognitive impairment, deaf-mutism, and neurological disabilities. L-thyroxine supplemental therapy, which had been initiated at the age of 6 months but ceased due to non-compliance, was reintroduced at presentation. GH therapy was initiated at 19 years of age, resulting in 42 cm linear growth, to a final height of 124 cm. Sequencing of POU1F1 revealed a previously described homozygous insertion mutation-c.580_581insT, p (Thr194Ilefs*7)-in exon 4 causing a frameshift that introduces a stop codon 7 amino acids downstream, leading to a severely truncated protein lacking the homeodomain. Conclusion: This case report sheds light on the natural history of untreated patients with POU1F1 mutations and raises awareness for early diagnosis and adequate treatment of central congenital hypothyroidism and GH deficiency.
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BACKGROUND: Germline mutations in the DNA polymerase genes POLD1 and POLE confer high risk for multiple colorectal adenomas and colorectal cancer. However, prevalence and the clinical phenotype of mutation carriers are still not fully characterized. OBJECTIVE: The purpose of this study was to assess the prevalence of germline mutations and to describe the genotype-phenotype correlation in POLD1 and POLE genes in Jewish subjects with multiple colorectal adenomas and/or early-onset mismatch repair proficient colorectal cancers. DESIGN: This study is a comparison of genetic and clinical data from affected and control groups. SETTINGS: The study was conducted at a high-volume tertiary referral center. PATIENTS: The study cohort included 132 subjects: 68 with multiple colorectal adenomas and 64 with early-onset mismatch repair proficient colorectal cancers. The control group included 5685 individuals having no colorectal cancer or colorectal adenomas. MAIN OUTCOME MEASURES: Study and control subjects were tested for POLD1 and POLE mutations and a clinical correlation was assessed. RESULTS: Eleven of the 132 study subjects (8.3%) carried either a POLD1 or a POLE mutation: 7 of 68 (10.3%) subjects with multiple colorectal adenomas and 4 of 64 (6.2%) subjects with early-onset mismatch repair proficient colorectal cancer. Three mutations were detected, showing statistical significance in frequency between study and control groups (p < 0.001). Eight of the 11 mutation carriers were Ashkenazi Jews carrying the same POLD1 mutation (V759I), implicating it as a possible low-to-moderate risk founder mutation. Phenotype of mutation carriers was notable for age under 50 at diagnosis, a propensity toward left-sided colorectal cancer, and extracolonic tumors (64%, 100%, and 27% of cases). LIMITATIONS: The study cohort was limited by its relatively small size. CONCLUSIONS: Germline mutations in POLD1 and POLE were found to be relatively frequent in our Jewish cohorts. Further studies are needed to clarify the importance of POLD1 and POLE mutations and to define the most suitable surveillance program for Jewish and other POLD1 and POLE mutation carriers. See Video Abstract at http://links.lww.com/DCR/A658.
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Adenoma/genética , Neoplasias Colorretais/genética , DNA Polimerase III/genética , DNA Polimerase II/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Adenoma/etnologia , Adulto , Idoso , Neoplasias Colorretais/etnologia , Reparo de Erro de Pareamento de DNA , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Judeus , Masculino , Pessoa de Meia-Idade , Mutação , Prevalência , Sistema de RegistrosRESUMO
STUDY QUESTION: Is there an association between spermatozoon genomic stability and vacuolar morphology and location? SUMMARY ANSWER: The genomic stability of spermatozoa is associated with specific characteristics of vacuolar morphology (depth) and location (cellular compartment, i.e. nucleus and equatorial region). WHAT IS KNOWN ALREADY: Genetic anomalies in sperm are correlated with semen abnormalities, yet the advantage of morphologically based selection of spermatozoa for IVF according to current criteria is controversial. Selection criteria based on the number of vacuoles and their size have been proposed and are widely applied. Nevertheless, it has not improved the ICSI success rates, suggesting the currently used vacuole criteria are incomplete. STUDY DESIGN, SIZE, DURATION: Normal sperm according to Motile Sperm Organelle Morphology Examination criteria (MSOME) and common vacuole grading were evaluated. An additional evaluation of sperm vacuole morphology according to novel vacuole criteria (i.e. location and depth) was conducted. An assessment to align these specific vacuolar morphology features with genomic stability was conducted among spermatozoa from infertile patients and healthy fertile donors aged 24-38 between June 2015 and July 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: Single spermatozoa (n = 53) from 16 infertile patients and 14 fertile donors were morphologically and genetically evaluated. Each spermatozoon was examined morphologically, by ultra-magnification ×6300, and genetically by a novel comparative genomic hybridization protocol, without the use of reference DNA, to assess chromosomal instability as evident by copy number variations (CNV). MAIN RESULTS AND THE ROLE OF CHANCE: We established an association between genomic stability and vacuolar morphology as a base for a new classification according to novel vacuolar criteria, specifically depth and location. Genomic instability was found to be related to these two main features of vacuoles and, surprisingly not to the number and size of vacuoles as in the previously proposed classifications. High CNV spermatozoa were characterized by vacuoles located in the nucleus and/or equatorial segment or by deep vacuoles, while, low CNV spermatozoa were characterized by a complete lack of vacuoles or non-deep vacuoles not located in the nucleus/equatorial segment. A putative threshold of ~265 CNV was deduced to distinguish between genetically stable and unstable spermatozoa, and 94% of the tested spermatozoa segregated accordingly. LIMITATIONS REASONS FOR CAUTION: A relatively small sample of spermatozoa were examined-53 in total. However, the association between vacuoles location and morphology and genomic stability was significant. This is the first study evaluating spermatozoon genomic stability with respect to vacuole morphology according to novel vacuole criteria (i.e. location and depth) and further investigation is warranted to verify the value of these criteria in larger sample size clinical studies. WIDER IMPLICATIONS OF THE FINDINGS: Our results, which are based on spermatozoon vacuoles morphological classification and genomic parameters, indicate an association between vacuoles morphology and location and genomic stability. The data presented herein suggest the existence of subpopulations of spermatozoa potentially appropriate for IVF-ICSI, as they appear normal according to the current MSOME and vacuoles classification, however they are almost certainly genetically damaged. As current criteria have yet to achieve an unequivocal evaluation of the implantation potential of a given spermatozoon, we propose novel criteria, based on specific vacuolar morphological traits; depth and location, as these were found aligned with genomic findings. STUDY FUNDING/COMPETING INTEREST(S): No funding was received for this study. The authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.
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Instabilidade Genômica/fisiologia , Infertilidade Masculina/diagnóstico , Espermatozoides/metabolismo , Vacúolos/metabolismo , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA , Humanos , Infertilidade Masculina/metabolismo , Masculino , Análise do Sêmen/métodosRESUMO
BACKGROUND: Sensitivity to macrocyclic lactones, which are commonly used in veterinary clinics, was first found in Rough Collies, and was attributed in 2001 to a 4 bp deletion in the MDR1 gene. The list of affected breeds currently includes 13 breeds. Researchers from different countries and continents examined the allelic frequencies of the nt230(del4) MDR1 mutation, emphasizing the clinical importance of this test not only to mutation-prone dogs, but also to their crosses and mongrels, since treatment of a deletion carrier with these compounds may lead to its death. In this study, the allelic frequencies of nt230(del4) MDR1 mutation in affected breeds, their crosses, unrelated pure breeds and mongrels are reported for the state of Israel (n = 1416 dogs). The Israeli data were compared with reports from the US, Europe, UK, Australia and Japan. RESULTS: The allelic frequencies of nt230(del4) MDR1 mutation in Israel for Australian, Swiss and German Shepherds (31%, 17% and 2.4%, respectively) are similar to the corresponding frequencies worldwide, much higher for Border Collies (4.8%), twice lower for Rough Collies (28%, compared to 55% or more elsewhere), and ~1% for mongrels. The frequencies for crosses of Australian Shepherd and Border Collies in Israel are 4 and 1.6 times lower, respectively, compared to the frequencies for the respective pure breeds. CONCLUSIONS: This work, that for the first time presents the frequency of nt230(del4) MDR1 mutation in Israel, along with a worldwide survey, has implications for clinicians, owners and breeders of sheepdogs and their crosses and supports the need for extra care in treatment and in future breeding. Of note, the relative proportion of affected breeds, in the overall tested dogs, might be higher than their actual proportion in Israel due to directed samples collection by veterinarians for clinical purposes, as these are mainly limited to certain affected breeds or dogs that resemble them.
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Cães/genética , Frequência do Gene , Mutação , Alelos , Animais , Cruzamento , Análise Mutacional de DNA , Feminino , Israel , Masculino , Deleção de Sequência , Especificidade da EspécieRESUMO
BACKGROUND: Congenital hypothyroidism of central origin (CH-C) is a rare disease in which thyroid hormone deficiency is caused by insufficient thyrotropin stimulation of a normal thyroid gland. A recently described syndrome of isolated CH-C and macroorchidism was attributed to loss-of-function mutations of the immunoglobulin superfamily, member 1 gene (IGSF1). PATIENTS AND METHODS: CH-C was diagnosed in three siblings. The TRH, TRHR, and TSHB genes were sequenced followed by whole-exome sequencing in the proband. A mutation identified in IGSF1 was analyzed by direct PCR sequencing in family members. The effects of the mutation were assessed by in vitro studies in HEK293 cells. RESULTS: The index case was negative for mutations in TRH, TRHR, and TSHB. Whole-exome sequencing revealed a novel insertion mutation in IGSF1, c.2284_2285insA, p.R762QfsX7, which was confirmed by direct PCR sequencing and was identified in six additional family members. The mutation introduces a frame-shift and premature stop codon in the seventh Ig loop, thereby truncating IGSF1. In vitro studies revealed that the mutated IGSF1-R762QfsX7 migrates as a doublet at â¼28 kDa, which is far smaller than the wild type protein (130-140 kDa). Both bands were endonuclease H sensitive, indicating immature glycosylation and failure of the protein to traffic out of the endoplasmic reticulum to the plasma membrane. Further phenotypic findings in the family included macroorchidism and infertility in the uncle and mild neurological phenotypes in the affected males, such as hypotonia, delayed psychomotor development, clumsy behavior, and attention deficit disorder. CONCLUSIONS: We identified a novel insertion mutation in the IGSF1 gene and further delineated the phenotype of the IGSF1-deficiency syndrome. Our findings indicate a possible association between an IGSF1 mutation and neurological phenotypes.
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Hipotireoidismo Congênito/genética , Hipotireoidismo/genética , Imunoglobulinas/genética , Proteínas de Membrana/genética , Pré-Escolar , Análise Mutacional de DNA , Células HEK293 , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Receptores do Hormônio Liberador da Tireotropina/genética , Irmãos , Tireotropina/genética , Hormônio Liberador de Tireotropina/genéticaRESUMO
BACKGROUND: Immune function is the most basic physiological process in humans and indeed throughout the animal kingdom. Interestingly, the vast majority of textbooks of physiology do not include a chapter on immunity. Our species survival is dependent on the diversity of the immune response and the ability for antigen presentation and effector mechanisms to be enormously promiscuous. As physicians, we are likely all too aware of how brief our life span is and the myriad of diseases and events that shorten it. It is not surprising that we question where our life comes from and our relationship within the universe. Many hypotheses have been offered regarding the likelihood that intelligent life exists elsewhere. We propose that such issues be discussed in the context of basic biologic observations on earth, such as the sight of a dense flock of tens of thousands of starlings maneuvering in rapid twists and turns at dusk before settling in trees for the night. The mathematical likelihood for life elsewhere was proposed by Frank Drake in a classic equation whose 'thesis' has stimulated the search for alien civilizations and the nature of life. A fundamental gap in this equation is the presence of a diverse immune response, a feature essential for survival of Life, presumably also extra-terrestrially.
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Imunidade , Vida , Origem da Vida , Animais , Aves , Humanos , MédicosRESUMO
BACKGROUND: Heterozygous germline mutations in any of the mismatch repair (MMR) genes, MLH1, MSH2, MSH6, and PMS2, cause Lynch syndrome (LS), an autosomal dominant cancer predisposition syndrome conferring a high risk of colorectal, endometrial, and other cancers in adulthood. Offspring of couples where both spouses have LS have a 1:4 risk of inheriting biallelic MMR gene mutations. These cause constitutional MMR deficiency (CMMRD) syndrome, a severe recessively inherited cancer syndrome with a broad tumor spectrum including mainly hematological malignancies, brain tumors, and colon cancer in childhood and adolescence. Many CMMRD children also present with café au lait spots and axillary freckling mimicking neurofibromatosis type 1. PROCEDURE: We describe our experience in seven CMMRD families demonstrating the role and importance of founder mutations and consanguinity on its prevalence. Clinical presentations included brain tumors, colon cancer, lymphoma, and small bowel cancer. RESULTS: In children from two nonconsanguineous Ashkenazi Jewish (AJ) families, the common Ashkenazi founder mutations were detected; these were homozygous in one family and compound heterozygous in the other. In four consanguineous families of various ancestries, different homozygous mutations were identified. In a nonconsanguineous Caucasus/AJ family, lack of PMS2 was demonstrated in tumor and normal tissues; however, mutations were not identified. CONCLUSIONS: CMMRD is rare, but, especially in areas where founder mutations for LS and consanguinity are common, pediatricians should be aware of it since they are the first to encounter these children. Early diagnosis will enable tailored cancer surveillance in the entire family and a discussion regarding prenatal genetic diagnosis.
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Proteínas Adaptadoras de Transdução de Sinal/genética , Adenosina Trifosfatases/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Consanguinidade , Reparo de Erro de Pareamento de DNA/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Efeito Fundador , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Adolescente , Manchas Café com Leite/genética , Criança , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Israel , Linfoma/genética , Masculino , Endonuclease PMS2 de Reparo de Erro de Pareamento , Proteína 1 Homóloga a MutL , Mutação , Linhagem , Adulto JovemRESUMO
BACKGROUND: Primary gonadal failure is characterised by primary amenorrhoea or early menopause in females, and oligospermia or azoospermia in males. Variants of the minichromosome maintenance complex component 8 gene (MCM8) have recently been shown to be significantly associated with women's menopausal age in genome-wide association studies. Furthermore, MCM8-knockout mice are sterile. The objective of this study was to elucidate the genetic aetiology of gonadal failure in two consanguineous families presenting as primary amenorrhoea in the females and as small testes and azoospermia in a male. METHODS AND RESULTS: Using whole exome sequencing, we identified two novel homozygous mutations in the MCM8 gene: a splice (c.1954-1G>A) and a frameshift (c.1469-1470insTA). In each consanguineous family the mutation segregated with the disease and both mutations were absent in 100 ethnically matched controls. The splice mutation led to lack of the wild-type transcript and three different aberrant transcripts predicted to result in either truncated or significantly shorter proteins. Quantitative analysis of the aberrantly spliced transcripts showed a significant decrease in total MCM8 message in affected homozygotes for the mutation, and an intermediate decrease in heterozygous family members. Chromosomal breakage following exposure to mitomcyin C was significantly increased in cells from homozygous individuals for c.1954-1G>A, as well as c.1469-1470insTA. CONCLUSIONS: MCM8, a component of the pre-replication complex, is crucial for gonadal development and maintenance in humans-both males and females. These findings provide new insights into the genetic disorders of infertility and premature menopause in women.
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Transtornos Gonadais/genética , Componente 8 do Complexo de Manutenção de Minicromossomo/genética , Mutação , Adolescente , Alelos , Instabilidade Cromossômica , Quebra Cromossômica , Mapeamento Cromossômico , Consanguinidade , Variações do Número de Cópias de DNA , DNA Complementar/genética , Exoma , Feminino , Expressão Gênica , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Transtornos Gonadais/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Recém-Nascido , Masculino , Ovário/metabolismo , Linhagem , Polimorfismo de Nucleotídeo Único , Sítios de Splice de RNA , RNA Mensageiro/genética , IrmãosRESUMO
Bi-allelic MUTYH gene mutations are associated with a clinical phenotype of multiple colorectal adenomas and an increased risk for colorectal cancer (CRC). It is unclear whether mono-allelic MUTYH gene carriers (heterozygotes) are also at increased risk for even few adenomas or cancer. In order to clarify an association between MUTYH heterozygotes and adenomas, we evaluated the frequency and types of MUTYH mutations and variants in 72 North-African Jews having few (≥3) colorectal adenomas with or without early onset (<50 years) CRC compared to 29 healthy controls. Germ-line DNA was analyzed for a panel of 6 MUTYH mutations and variants, and Sanger sequencing of the entire MUTYH gene was performed for mono-allelic MUTYH mutation carriers. APC gene mutations and Lynch syndrome were excluded in the relevant cases according to accepted clinical criteria. Twenty-two of the 72 adenoma subjects (30.5%) had MUTYH mutations or variants. Nine were homozygotes or compound heterozygotes: all had >10 adenomas and one had CRC. Thirteen others were mono-allelic carriers (heterozygotes) of a single MUTYH mutation: six had more than ten adenomas and seven had less than ten adenomas; of these 13 mono-allelic carriers, six had a neoplasm: three CRCs and three extra-intestinal tumors. Eleven of the thirteen mono-allelic carriers with adenomas had a family history of cancer in first or second degree relatives. A multivariable model showed positive correlation between G396D, Y179C and 1186 ins GG mutations and number of adenomas (OR 8.6, 10.2 and 14.4, respectively). The Q324H variant was negatively associated with the number of adenomatous polyps (OR -5.23). In conclusion, MUTYH mutations are prevalent among Jews of North-African origin with colorectal adenomas with or without early onset CRC. Mono-allelic MUTYH carriers with a family history of cancer had a clinical phenotype that varied from having only few adenomas to multiple (>10) adenomas. These findings support MUTYH testing in patients with even few adenomas and suggest the consideration of increased surveillance in mono-allelic carriers with a family history of cancer.
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Adenoma/genética , Neoplasias Colorretais/genética , DNA Glicosilases/genética , Mutação , Pólipos Adenomatosos/genética , Adulto , África do Norte/etnologia , Idoso , Alelos , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Heterozigoto , Humanos , Israel/etnologia , Judeus/genética , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: In recent years, the perception of transposable genetic elements has changed from "junk DNA" to a focus of interest when appearing near or inside genes. Bov-A2 is a short interspersed nuclear element (SINE) that was first found in Bovidae and later in other ruminants. This retroposon is mostly used as a marker for phylogenetic analysis. RESULTS: We describe insertions of Bov-A2 in the promoter region of TP53, a key tumor suppressor gene that is indispensable for diverse developmental processes, in Antilopinae and Tragelaphini (belonging to the Bovinae subfamily). In Tragelaphini two Bov-A2 elements were inserted sequentially, whereas in 5 tribes of Antilopinae only one Bov-A2 element was inserted, in a different site and reverse orientation. The entrance site in both cases employed short palindromes that can form hairpin secondary structures. Interestingly, mutations that create or disrupt base pairing in the palindrome sequence dictated the presence or absence of Bov-A2, such as in the domestic cow and buffalo, which lack Bov-A2. Transcription factor binding site analysis revealed unique binding sites for STAT3 and NFκB within the Bov-A2 sequence, which together with TP53 itself are known to play a crucial role in mammary involution. CONCLUSIONS: This report demonstrates how short palindromes serve as hot spots for Bov-A2 retroposon insertion into the mammalian genome. The strict correlation between point mutation in the palindromes and the presence/absence of Bov-A2 retroposon insertions, questions the use of singular insertion events as valid phylogenetic markers inside families. Bov-A2 insertion into the TP53 promoter in Antilopinae and Tragelaphini may not only provide a genetic network that regulates mammary involution, but can also answer the need for rapid mammary involution in Savanna antelopes after weaning, partially in response to predation stress. The absence of Bov-A2 in domestic bovids may constitute the molecular background for greater lactation persistency.
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Evolução Molecular , Filogenia , Elementos Nucleotídeos Curtos e Dispersos/genética , Proteína Supressora de Tumor p53/genética , Animais , Búfalos/genética , Bovinos , Feminino , Redes Reguladoras de Genes/genética , Genoma , Leite , Dados de Sequência Molecular , Fator de Transcrição STAT3/genéticaRESUMO
BACKGROUND: Loss-of-function mutations in the thyrotropin receptor (TSHR) gene lead to resistance to TSH (RTSH) presenting with either congenital hypothyroidism (CH) or subclinical hypothyroidism (SCH). Despite several reports of patients with TSHR mutations, data on the long-term outcome of this condition are limited, and no consensus exists on the need for hormone replacement therapy. The aim of the present study was to assess the long-term outcome in children and adolescents with RTSH due to TSHR mutations. METHODS: The TSHR gene was sequenced in 94 subjects (aged 3 days-21 years) with either nonautoimmune SCH or CH with RTSH. RESULTS: Twenty-seven subjects (29%) carried mutations in TSHR. Fifteen infants were identified by neonatal screening, and the other 79 patients were detected in the process of testing for various other conditions or because of family occurrence of thyroid test abnormalities. Six different mutations were identified: c.484C>G (p.P162A), c.202C>T (p.P68S), c.790C>T (p.P264S), c.269A>C (p.Q90P), c.1957C>G (p.L653V), and c.1347C>T (p.R450C). Twelve subjects were homozygous, three were compound heterozygous, and 12 were heterozygous. Mean serum TSH levels at diagnosis and at last visit were significantly higher in patients with TSHR mutations than in those without mutations (29.04 vs. 14.15, p=0.002; 31.73 vs. 6.19, p<0.0001, respectively). Homozygous patients had a more severe phenotype (TSH 53.6 vs. 9.24, p<0.0001). Mean serum free thyroxine (fT4) levels at the last visit were significantly lower than at the first visit in the homozygous individuals (p=0.05) for a follow-up period of as long as 11 years. Heterozygous subjects had only mild hyperthyrotropinemia with stable TSH levels. However, homozygous subjects showed a trend toward increased TSH and decreased fT4 with time. CONCLUSION: SCH in heterozygotes with TSHR mutations is a stable compensated condition with an appropriately adjusted set point for pituitary-thyroid feedback that does not require replacement therapy. However, homozygous subjects, with incompletely compensated SCH, show reduced fT4 levels over time and may require levothyroxine treatment. Replacement therapy should be considered on an individual basis, and long-term follow up is recommended.
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Hipotireoidismo Congênito/genética , Hipotireoidismo/genética , Mutação , Receptores da Tireotropina/genética , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Heterozigoto , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Triagem Neonatal , Testes de Função Tireóidea , Glândula Tireoide/fisiopatologia , Tireotropina/metabolismo , Resultado do Tratamento , Adulto JovemRESUMO
Gain-of-function somatic mutations introducing cysteines to either the extracellular or to the transmembrane domain (TMD) in interleukin-7 receptor α (IL7R) or cytokine receptor-like factor 2 (CRLF2) have been described in acute lymphoblastic leukemias. Here we report noncysteine in-frame mutations in IL7R and CRLF2 located in a region of the TMD closer to the cytosolic domain. Biochemical and functional assays showed that these are activating mutations conferring cytokine-independent growth of progenitor lymphoid cells in vitro and are transforming in vivo. Protein fragment complementation assays suggest that despite the absence of cysteines, the mechanism of activation is through ligand-independent dimerization. Mutagenesis experiments and ConSurf calculations suggest that the mutations stabilize the homodimeric conformation, positioning the cytosolic kinases in predefined orientation to each other, thereby inducing spontaneous receptor activation independently of external signals. Hence, type I cytokine receptors may be activated in leukemia through 2 types of transmembrane somatic dimerizing mutations.
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Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Receptores de Citocinas/genética , Receptores de Interleucina-7/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Células Cultivadas , Cisteína , Análise Mutacional de DNA , Feminino , Citometria de Fluxo , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Mutagênese/genética , Transdução de Sinais/genética , Transdução GenéticaRESUMO
Glucose transporter protein type 1 deficiency syndrome is a metabolic disorder manifesting as cognitive impairment, acquired microcephaly, epilepsy, and/or movement disorder caused by mutations in the SLC2A1 gene. We describe a cohort of isolated and familial cases of glucose transporter protein type 1 deficiency syndrome, emphasizing seizure semiology, electroencephalographic (EEG) features, treatment response and mutation pathogenicity. SLC2A1 mutations were detected in 3 sporadic and 4 familial cases. In addition, mutations were identified in 9 clinically unaffected family members in 2 families. The phenotypic spectrum of glucose transporter protein type 1 deficiency is wider than previously recognized, with considerable intra-familial variation. Diagnosis requires either hypoglycorrachia followed by SLC2A1 sequencing or direct gene sequencing. A ketogenic diet should be the first line of treatment, but more flexible diets, like the Atkins modified diet, can also be followed. Carbonic anhydrase inhibitors, such as acetazolamide or zonisamide, can be effective for seizure control.
Assuntos
Erros Inatos do Metabolismo dos Carboidratos/genética , Erros Inatos do Metabolismo dos Carboidratos/fisiopatologia , Transportador de Glucose Tipo 1/deficiência , Proteínas de Transporte de Monossacarídeos/deficiência , Adolescente , Encéfalo/fisiopatologia , Erros Inatos do Metabolismo dos Carboidratos/diagnóstico , Erros Inatos do Metabolismo dos Carboidratos/terapia , Inibidores da Anidrase Carbônica/uso terapêutico , Criança , Pré-Escolar , Estudos de Coortes , Análise Mutacional de DNA , Diagnóstico Diferencial , Dieta Cetogênica , Eletroencefalografia , Família , Transportador de Glucose Tipo 1/genética , Humanos , Proteínas de Transporte de Monossacarídeos/genética , Mutação , Linhagem , Fenótipo , Convulsões/genética , Convulsões/fisiopatologia , Convulsões/terapia , Adulto JovemRESUMO
Cancer is often caused by deregulation of normal developmental processes. Here, we review recent research on the aberrant activation of two hematopoietic cytokine receptors in acute lymphoid leukemias. Somatic events in the genes for thymic stromal lymphopoietin and Interleukin 7 receptors as well as in their downstream JAK kinases result in constitutive ligand-independent activation of survival and proliferation in B and T lymphoid precursors. Drugs targeting these receptors or the signaling pathways might provide effective therapies of these leukemias.
Assuntos
Citocinas/imunologia , Interleucina-7/imunologia , Modelos Biológicos , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Receptores de Citocinas/metabolismo , Receptores de Interleucina-7/metabolismo , Transdução de Sinais/imunologia , Proteínas Adaptadoras de Transdução de Sinal , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Janus Quinases/genética , Janus Quinases/metabolismo , Mutação/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Células Precursoras de Linfócitos B/imunologia , Células Precursoras de Linfócitos T/imunologia , Proteínas/genética , Proteínas/metabolismo , Receptores de Citocinas/genética , Receptores de Interleucina-7/genética , Transdução de Sinais/genética , Linfopoietina do Estroma do TimoRESUMO
We are overwhelmed by warnings about inevitable geophysical and human problems. Earth is beset by escalating, manmade, environmental crises and our exploding population will eventually lack water, food and vital materials. This suggests, together with increasing poverty, deepening social unrest and advanced techniques for mass killing, that civilization will break down long before atmospheric CO2 or resistant microbes become catastrophic. Despite intensive searching, life has not been found in space, even though thousands of planets have been found and life there may be as problematic and unpredictable as on Earth. The human brain is already a 'universe', with 85 billion neurons and a hundred trillion synapses, more than the stars in our galaxy. Understanding consciousness, the brain, its aging and pathologies, and eliminating the propensity for human aggression are urgent challenges. During 1958-2012, NASA spent $800 billion. In contrast, the annual cost of brain disease in the U.S. is $600 billion, more than cardiovascular disease and cancer combined. We suggest that a massive switching of financial and human resources is required to explore the full potential of the human brain. Visiting Mars can wait. We further propose a novel Two-Brain Hypothesis: the animal 'brain' evolved as two fundamentally different though interdependent, complementary organs: one electroionic (tangible, known and accessible), and the other, electromagnetic (intangible and difficult to access)--a relatively independent, stable, structured and functional 3D compendium of variously induced interacting EM fields.
Assuntos
Encéfalo , Fenômenos Eletromagnéticos , Vida , Modelos Neurológicos , Pesquisa Biomédica , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Civilização , Meio Ambiente , HumanosRESUMO
The role of carbon in the development of life and as the structural backbone of all organisms is universally accepted and an essential part of evolution. However, the molecular basis is largely unknown and the interactions of carbon with nitrogen and oxygen in space are enigmatic. In 1985, the previously unknown form of carbon, coined fullerene, was discovered. We hypothesize that by virtue of the unique properties of fullerene, this hollow, ultra-robust, large, purely carbon molecule was the earliest progenitor of life. It acted as a stable universal biologic template on which small molecules spontaneously assembled and then formed, by further assembly, a surface mantle (here termed rosasome) of larger molecules. We submit that this process, by its inherent flexibility, initiated evolution, allowing the emergence of parallel diverse rosasome lines responding selectively to varying spatial environments. For example, rosasomal lines mantled with nucleotide and peptide layers are conceived as primordial forerunners of the ubiquitous ribosome. Moreover, the parallel independent and interdependent evolution of rosasome lines would be more rapid than sequential development, refute precedence of either DNA or RNA, and explain the evolution of integration of two subunits with different structures and functions in ribosomes and of the triplet nature of the codon. Based on recent astronomical data, this hypothesis supports the concept that life is not a singularity. This concept also suggests a potential vehicle for therapeutics, biotechnology and genetic engineering.
Assuntos
DNA/genética , Evolução Molecular , Fulerenos , Modelos Biológicos , Origem da Vida , Biossíntese Peptídica/genética , Ribossomos/genética , HumanosRESUMO
Human cancers display substantial intratumoral genetic heterogeneity, which facilitates tumor survival under changing microenvironmental conditions. Tumor substructure and its effect on disease progression and relapse are incompletely understood. In the present study, a high-throughput method that uses neutral somatic mutations accumulated in individual cells to reconstruct cell lineage trees was applied to hundreds of cells of human acute leukemia harvested from multiple patients at diagnosis and at relapse. The reconstructed cell lineage trees of patients with acute myeloid leukemia showed that leukemia cells at relapse were shallow (divide rarely) compared with cells at diagnosis and were closely related to their stem cell subpopulation, implying that in these instances relapse might have originated from rarely dividing stem cells. In contrast, among patients with acute lymphoid leukemia, no differences in cell depth were observed between diagnosis and relapse. In one case of chronic myeloid leukemia, at blast crisis, most of the cells at relapse were mismatch-repair deficient. In almost all leukemia cases, > 1 lineage was observed at relapse, indicating that diverse mechanisms can promote relapse in the same patient. In conclusion, diverse relapse mechanisms can be observed by systematic reconstruction of cell lineage trees of patients with leukemia.