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INTRODUCTION: The utilization of radiation shielding material positioned between the both breasts are crucial for the reduction of glandular dose and the safeguarding of the contralateral breast during mammographic procedures. This study proposes an alternative substance for shielding the contralateral breast from radiation exposure during mammography screening. METHODS: In this study, we present an analysis of the shielding effectiveness of transparent glass that has been doped with Tantalum (V) oxide encoded as BTZT6. The evaluation of this shielding material was conducted using the MCNPX code, specifically for the ipsilateral and contralateral breasts. The design of the left and right breast phantoms involved the creation of three-layer heterogeneous breast phantoms, consisting of varying proportions of glandular tissue (25%, 50%, and 75%). The design of BTZT6 and lead-acrylic shielding screens is implemented using the MCNPX code. The comparative analysis of dose outcomes is conducted to assess the protective efficacy of BTZT6 and lead-acrylic shielding screens. RESULTS: The utilization of BTZT6 shielding material resulted in a reduction in both breast dose and skin dose exposure when compared to the lead-acrylic shield. CONCLUSION: Based on the findings acquired, the utilization of BTZT6 shielding material screens during mammography procedures involving X-rays with energy levels ranging from 26 to 30 keV is associated with a decrease in radiation dose. IMPLICATIONS FOR PRACTICE: It can be inferred that the utilization of BTZT6 demonstrates potential efficacy in mitigating excessive radiation exposure to the breasts and facilitating the quantification of glandular doses in mammography procedures.
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Tantálio , Tomografia Computadorizada por Raios X , Humanos , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Mamografia/métodos , Mama/diagnóstico por imagemRESUMO
AIM: Mucopolysaccharidosis type III B (MPS IIIB) is an autosomal recessive lysosomal storage disease caused by mutations in the NAGLU gene which codes the lysosomal enzyme alpha-N-acetylglucosaminidase. The major symptoms of the disease are cognitive and neurological defects. In this study, the molecular spectrums of 13 MPS IIIB patients were evaluated. MATERIAL AND METHODS: Thirteen MPS IIIB patients from 11 families were included in this study. All patients were both clinically and molecularly diagnosed. NAGLU gene sequencing was performed using a next generation sequencing platform (Illumina MiSeq). Demographic, clinical and laboratory findings of the patients were obtained via the hospital records. RESULTS: Ten different mutations from the 13 MPS IIIB patients were identified. Eight of the 10 mutations were missense, one was splice site, and one large deletion was also observed. Two mutations c.509G>T (p.Gly170Val) and c.700C>G (p.Arg234Gly) have been defined for the first time in this study. CONCLUSION: Our study expanded the mutation spectrum of the NAGLU gene thereby contributing to the improved genetic counselling of MPS IIIB patients. Confirming the literature, missense mutations were also found to be the most common NAGLU mutations in our study.
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The group of chondrodysplasia with multiple dislocations includes several entities, characterized by short stature, dislocation of large joints, hand and/or vertebral anomalies. Other features, such as epiphyseal or metaphyseal changes, cleft palate, intellectual disability are also often part of the phenotype. In addition, several conditions with overlapping features are related to this group and broaden the spectrum. The majority of these disorders have been linked to pathogenic variants in genes encoding proteins implicated in the synthesis or sulfation of proteoglycans (PG). In a series of 30 patients with multiple dislocations, we have performed exome sequencing and subsequent targeted analysis of 15 genes, implicated in chondrodysplasia with multiple dislocations, and related conditions. We have identified causative pathogenic variants in 60% of patients (18/30); when a clinical diagnosis was suspected, this was molecularly confirmed in 53% of cases. Forty percent of patients remain without molecular etiology. Pathogenic variants in genes implicated in PG synthesis are of major importance in chondrodysplasia with multiple dislocations and related conditions. The combination of hand features, growth failure severity, radiological aspects of long bones and of vertebrae allowed discrimination among the different conditions. We propose key diagnostic clues to the clinician.
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Deficiência Intelectual/genética , Anormalidades Musculoesqueléticas/genética , Osteocondrodisplasias/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/fisiopatologia , Masculino , Anormalidades Musculoesqueléticas/diagnóstico , Anormalidades Musculoesqueléticas/diagnóstico por imagem , Anormalidades Musculoesqueléticas/fisiopatologia , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/fisiopatologia , Radiografia , Sequenciamento do ExomaRESUMO
Keutel syndrome (KS) is an autosomal recessive disease characterised by abnormal cartilage calcification, brachytelephalangism, peripheral pulmonary artery stenosis, hearing loss and midface retrusion. KS is caused by homozygous mutations in MGP, a gene encoding Matrix Gla protein which acts as a calcification inhibitor in extracellular matrix. We present two Turkish sisters (22 and 13 years old) who had abnormal cartilage calcification, brachytelephalangism, congenital heart defect and chronic asthmatic bronchitis. The patients were homozygous for c.62-2A>G (IVS1-2 A>G) mutation in MGP gene. Abnormal cartilage calcification, brachytelephalangism and midfacial retrusion are the hallmarks of KS. It was observed that the younger sister had striking cartilaginous calcifications, midfacial retrusion and severe brachytelephalangism while her older sister had mild costal cartilaginous calcifications and brachytelephalangism without any midfacial retrusion. Intrafamiliar clinical variability for KS has not been described previously.
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Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Calcinose/genética , Calcinose/patologia , Proteínas de Ligação ao Cálcio/genética , Doenças das Cartilagens/genética , Doenças das Cartilagens/patologia , Proteínas da Matriz Extracelular/genética , Deformidades Congênitas da Mão/genética , Deformidades Congênitas da Mão/patologia , Estenose da Valva Pulmonar/genética , Estenose da Valva Pulmonar/patologia , Adolescente , Adulto , Feminino , Homozigoto , Humanos , Mutação , Irmãos , Adulto Jovem , Proteína de Matriz GlaRESUMO
Sotos syndrome is a well-known overgrowth syndrome characterized by excessive growth during childhood, macrocephaly, distinctive facial appearance and learning disability. This disorder is caused by mutations or deletions in NSD1 gene. The aim of this study is to examine the relationship between the neuroimaging and clinical features of children with Sotos syndrome. Six Turkish children with Sotos syndrome were followed up about 3-7 years. The diagnosis was confirmed with molecular genetic analysis. We identified the pathogenic NSD1 mutation including three novel in all patients. All the patients had a characteristic facial gestalt of Sotos syndrome consisting of triangular face with prominent forehead, frontoparietal sparseness of hair and small nose. However, the degree of psychomotor and intellectual development was variable. Severe learning defect and speech delay were remarkable in two patients. The neuroimaging analysis showed abnormalities in four of six patients including bilateral large ventricles, thinning of the corpus callosum and persistent cavum septum pellucidum et vergae. Typical craniofacial appearance is the primary finding for the diagnosis of the disease even in the infantile period. However, the degree of psychomotor and intellectual development is very variable and does not correlate with the neuroimaging findings.
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Anormalidades Craniofaciais/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Nucleares/genética , Síndrome de Sotos , Criança , Pré-Escolar , Anormalidades Craniofaciais/patologia , Feminino , Seguimentos , Histona Metiltransferases , Histona-Lisina N-Metiltransferase , Humanos , Masculino , Síndrome de Sotos/genética , Síndrome de Sotos/patologia , Síndrome de Sotos/fisiopatologia , TurquiaRESUMO
BACKGROUND: Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterised by hypotonia, ataxia, cognitive impairment, abnormal eye movements, respiratory control disturbances and a distinctive mid-hindbrain malformation. JS demonstrates substantial phenotypic variability and genetic heterogeneity. This study provides a comprehensive view of the current genetic basis, phenotypic range and gene-phenotype associations in JS. METHODS: We sequenced 27 JS-associated genes in 440 affected individuals (375 families) from a cohort of 532 individuals (440 families) with JS, using molecular inversion probe-based targeted capture and next-generation sequencing. Variant pathogenicity was defined using the Combined Annotation Dependent Depletion algorithm with an optimised score cut-off. RESULTS: We identified presumed causal variants in 62% of pedigrees, including the first B9D2 mutations associated with JS. 253 different mutations in 23 genes highlight the extreme genetic heterogeneity of JS. Phenotypic analysis revealed that only 34% of individuals have a 'pure JS' phenotype. Retinal disease is present in 30% of individuals, renal disease in 25%, coloboma in 17%, polydactyly in 15%, liver fibrosis in 14% and encephalocele in 8%. Loss of CEP290 function is associated with retinal dystrophy, while loss of TMEM67 function is associated with liver fibrosis and coloboma, but we observe no clear-cut distinction between JS subtypes. CONCLUSIONS: This work illustrates how combining advanced sequencing techniques with phenotypic data addresses extreme genetic heterogeneity to provide diagnostic and carrier testing, guide medical monitoring for progressive complications, facilitate interpretation of genome-wide sequencing results in individuals with a variety of phenotypes and enable gene-specific treatments in the future.
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Cerebelo/anormalidades , Heterogeneidade Genética , Retina/anormalidades , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Cerebelo/patologia , Estudos de Coortes , Análise Mutacional de DNA , Anormalidades do Olho/genética , Anormalidades do Olho/patologia , Estudos de Associação Genética , Humanos , Doenças Renais Císticas/genética , Doenças Renais Císticas/patologia , Modelos Teóricos , Linhagem , Retina/patologia , Análise de Sequência de DNARESUMO
We present an 18-day old boy with bilateral cervical cutaneous defect in the retroauricular region, low-set and posteriorly rotated ears, bilateral microphtalmia and bilateral pseudocleft of the upper lip. Histopathological evaluation of cervical cutaneous defect showed ulceration on the surface and ectopic thymus tissue in the deep dermis with cortex, medulla and Hassal's corpuscles. Clinical findings led to the diagnosis of Branchio-oculo-facial syndrome, characterized by branchial defects (erythematous cutaneous defects in cervical region), ocular anomalies (microphthalmia, anophthalmia, lacrimal duct obstruction, coloboma, cataract, ptosis) and facial defects (cleft lip and/or palate, pseudocleft or abnormal philtrum). DNA sequencing showed a novel heterozygous mutation, c.731T>C (p.L244P), in TFAP2A gene confirming the diagnosis of this rare autosomal dominant developmental disorder with variable clinical findings.
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Anormalidades Múltiplas/genética , Síndrome Brânquio-Otorrenal/genética , Timo/anormalidades , Fator de Transcrição AP-2/genética , Anormalidades Múltiplas/patologia , Síndrome Brânquio-Otorrenal/patologia , Humanos , Recém-Nascido , Masculino , Mutação/genética , Timo/patologia , Timo/cirurgiaRESUMO
BACKGROUND/AIMS: Osteoporosis-pseudoglioma (OPPG) syndrome is a rare disorder characterized by congenital or infancy-onset visual loss and severe juvenile osteoporosis. OPPG is caused by homozygous mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. We present three novel homozygous LRP5 mutations found in 3 unrelated Turkish children with consanguineous parents, along with clinical phenotypes and response to treatment with bisphosphonates (bisP). METHODS/RESULTS: The LRP5 gene was analyzed by direct sequencing after PCR amplification. Mutation screening for LRP5 revealed homozygous nonsense R1002X mutation in the first patient and homozygous missense mutations V336M and G507S in the second and third patient, respectively. The parents were heterozygous for these mutations. The patients' eye symptoms began during the first months of life but the OPPG diagnoses were made based on skeletal deformities and osteopenia after 4 years of age. The patients' bone mineral density Z scores were very low and consistent with osteopenia. All patients were treated with bisP for 3.5-7 years. CONCLUSION: We report three novel LRP5 mutations in 3 Turkish patients with OPPG. We show that the response of bisP therapy has improved the lumbar spinal bone mineral density Z scores and the patients' quality of life as the bone pains decreased.
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Conservadores da Densidade Óssea/uso terapêutico , Difosfonatos/uso terapêutico , Resistência a Medicamentos , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Mutação , Osteogênese Imperfeita/tratamento farmacológico , Osteogênese Imperfeita/genética , Substituição de Aminoácidos , Densidade Óssea/efeitos dos fármacos , Criança , Pré-Escolar , Códon sem Sentido , Consanguinidade , Oftalmopatias/tratamento farmacológico , Oftalmopatias/genética , Feminino , Heterozigoto , Humanos , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Masculino , Mutação de Sentido Incorreto , Osteogênese Imperfeita/metabolismo , Osteogênese Imperfeita/fisiopatologia , Medição da Dor/efeitos dos fármacos , TurquiaRESUMO
We described trisomy 8 mosaicism in a 6-month-old boy with left corneal leukoma, strabismus, posterior urethral valve, tibial bowing and congenital pseudarthrosis of the tibia (CPT) on graphic of left tibia. The patient also had some minor anomalies such as short philtrum, full everted lower lip, microretrognathia, flexion contracture on his left thumb, deep palmar and plantar creases and three cafe-au-lait macules (CALM) larger than 1 cm on the abdomen. Peripheral blood karyotype analysis of the patient showed 46,XY(10%)/47,XY,+8 (90%)). Mosaic trisomy 8 is a rare syndrome characterized by renal, cardiac, ophthalmologic anomalies, dysmorphic facial features and some skeletal manifestations. When re-evaluated at 2 years of age, his gross motor development was delayed and he also had 12 CALM larger than 1 cm, hence the patient fulfilled NIH diagnostic criteria for Neurofibromatosis type 1 (NF 1) based on the CALM and CPT. A truncating mutation was found through comprehensive NF1 mutation analysis, i.e., c.1019_1020delCT (p.Ser340CysfsX12). Here we report a patient with both mosaic trisomy 8 and NF1, which was not described previously.
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Anormalidades Múltiplas/genética , Cromossomos Humanos Par 8/genética , Mosaicismo , Neurofibromatose 1/genética , Trissomia/genética , Anormalidades Múltiplas/diagnóstico , Biópsia , Pré-Escolar , Bandeamento Cromossômico , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/genética , Seguimentos , Humanos , Lactente , Cariotipagem , Masculino , Neurofibromatose 1/diagnóstico , Pseudoartrose/genética , Pseudoartrose/patologia , Tíbia/anormalidades , Tíbia/patologia , Trissomia/diagnósticoRESUMO
We describe a girl with microcephaly, short stature, coarse face, severe growth and developmental delay, seizures, hypertonia, bilateral flexion contractures of the knees, and a de novo 21;21 translocation trisomy 21 in peripheral blood lymphocytes. Fluorescence in situ hybridization (FISH) analysis confirmed the trisomy 21 translocation using whole chromosome painting probe 21 (WCP21). Chromosome analysis which was also performed on skin fibroblasts and revealed mosaicism for a translocation trisomy 21 cell line (22.3%) as well as a second cell line consisting of one normal chromosome 21 and a small ring chromosome 21 derived from the translocation 21q21q (61%) and a third line consisting of monosomy 21 (16.7%). FISH analyses by LS121 probe for the critical (21q22.2-22.3) region of Down syndrome (DS) on interphase blood cells resulted with 30% two signals and 70% three signals, skin fibroblasts showed 84% single signal, 9% two signals and 7% three signals. The size of ring chromosome 21 in skin fibroblasts was very small and probably there was a large, more proximally located deletion including chromosome 21q22 band. We consider that the atypical DS phenotype of the patient originated from the small ring chromosome 21 and the monosomy 21 in the skin fibroblasts and other tissues not available for analysis. Therefore, the clinical findings of the patient were most similar to monosomy 21 mosaicism syndrome.
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Cromossomos Humanos Par 21/genética , Síndrome de Down/genética , Monossomia , Mosaicismo , Cromossomos em Anel , Criança , Feminino , HumanosRESUMO
We describe a family with progressive skeletal dysplasia and severe spinal involvement, short stature, premature arthrosis and joint contractures diagnosed as spondyloepiphyseal dysplasia Omani type. Mutation analysis in CHST3, the gene encoding for the chondroitin 6-O-sulfotransferase-1 (C6ST-1), revealed a homozygous missense mutation (T141M) in exon 3 in all three affected members of the family. Using recombinant C6ST-1, we showed that the identified missense mutation results in a reduction of C6ST-1 activity to 24-29% of the wild type protein. In addition to the previously noted skeletal features, affected members of this family also had cardiac involvement including mitral, tricuspid and/or aortic regurgitations and type E brachydactyly.
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Cardiopatias Congênitas/genética , Mutação de Sentido Incorreto , Osteocondrodisplasias/genética , Sulfotransferases/genética , Criança , Análise Mutacional de DNA , Saúde da Família , Feminino , Homozigoto , Humanos , Masculino , Linhagem , Carboidrato SulfotransferasesRESUMO
We report a 15 month old boy with prominent metopic suture, epicanthal folds, strabismus, low-set ears, microretrognathia, large anterior fontanel, bilateral simian creases, muscular hypotonia, and severe psychomotor retardation. He also had West syndrome. An electroencephalogram showed hypsarrythmia, and cranial MR indicated a myelinisation delay. Standard karyotyping showed additional material on one chromosome 9p. Using FISH, a terminal 7q duplication spanning 26 Mb in size and a terminal 9p deletion sized (at least) 9.1 Mb were identified. The father had a karyotype of t(7;9)(q33;p23) and the mother's karyotype was normal. The boy presented typical facial features of the distal 7q duplication syndrome but no genital anomalies attributable to his distal 9p deletion. We assume that the severe epilepsy is likely due to the trisomy 7q.
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Duplicação Gênica , Espasmos Infantis/genética , Translocação Genética/genética , Anormalidades Múltiplas , Aberrações Cromossômicas , Bandeamento Cromossômico , Coloração Cromossômica , Cromossomos Humanos Par 7 , Humanos , Hibridização in Situ Fluorescente , Lactente , Cariotipagem , Masculino , Fenótipo , TurquiaRESUMO
Cardio-facio-cutaneous (CFC) and Costello syndrome (CS) are congenital disorders with a significant clinical overlap. The recent discovery of heterozygous mutations in genes encoding components of the RAS-RAF-MAPK pathway in both CFC and CS suggested a similar underlying pathogenesis of these two disorders. While CFC is heterogeneous with mutations in BRAF, MAP2K1, MAP2K2 and KRAS, HRAS alterations are almost exclusively associated with CS. We carried out a comprehensive mutation analysis in 51 CFC-affected patients and 31 individuals with CS. Twelve different BRAF alterations were found in twenty-four patients with CFC (47.0%), two MAP2K1 mutations in five (9.8%) and two MAP2K2 sequence variations in three CFC-affected individuals (5.9%), whereas three patients had a KRAS alteration (5.9%). We identified four different missense mutations of HRAS in twenty-eight cases with CS (90.3%), while KRAS mutations were detected in two infants with a phenotype meeting criteria for CS (6.5%). In 14 informative families, we traced the parental origin of HRAS alterations and demonstrated inheritance of the mutated allele exclusively from the father, further confirming a paternal bias in the parental origin of HRAS mutations in CS. Careful clinical evaluation of patients with BRAF and MAP2K1/2 alterations revealed the presence of slight phenotypic differences regarding craniofacial features in MAP2K1- and MAP2K2-mutation positive individuals, suggesting possible genotype-phenotype correlations.
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Anormalidades Múltiplas/genética , Fácies , Cardiopatias Congênitas/genética , Mutação , Anormalidades da Pele/genética , Adulto , Criança , Análise Mutacional de DNA , Deficiências do Desenvolvimento , Humanos , Deficiência Intelectual , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 2/genética , Fenótipo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras) , Síndrome , Proteínas ras/genéticaRESUMO
The prevalence of the HLA-DQA1 and DQB1 alleles in 55 Turkish children with celiac disease and 50 control subjects was investigated by using an allele-specific DNA-based polymerase chain reaction-sequence-specific primer (PCR-SSP) method. The frequency of the DQA1*0501 and DQB1*02 alleles was higher in celiac patients than in controls. The DQA1B1 (*0501; *02) haplotype was present in 46 (83.6%) patients and only in 12 (24%) controls. The remaining 9 celiac patients which were negative for DQA1B1 (*0501;*02) carried the DQA1B1 (*03;*0302) haplotype. We found an excess homozygosity of the DQB1*02 allele and the DQA1B1 (*0501;*02) haplotype in the patients. No statistically significant correlation was found between the homozygosity of this haplotype or the DQB1*02 allele and an earlier onset of the disease.
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Doença Celíaca/genética , Antígenos HLA-DQ/genética , Adolescente , Alelos , Doença Celíaca/imunologia , Criança , Feminino , Deleção de Genes , Frequência do Gene , Genótipo , Cadeias alfa de HLA-DQ , Cadeias beta de HLA-DQ , Haplótipos , Homozigoto , Humanos , Masculino , Polimorfismo Conformacional de Fita Simples , TurquiaRESUMO
Campomelic dysplasia is a rare neonatal skeletal malformation syndrome mainly characterized by congenital bowing and angulation of long bones in combination with other skeletal and extraskeletal defects. Two thirds of karyotypic males exhibit male-to-female sex reversal. Point mutations within SOX9 in 17q24-25 or rearrangements upstream to SOX9 as well as a deletion of a complete gene, causing haploinsufficiency of the gene product, have been detected in some patients. Recurrent mutations appear to be rare and most mutations detected in campomelic dysplasia are family specific. Here, we report on a Turkish patient with a 46,XY karyotype affected by campomelic dysplasia without sex reversal. Sequencing the SOX9 gene revealed a heterozygous Ala119Val mutation in exon 1, coding for the highly conserved HMG-box of the gene. This mutation is not present in the parents' lymphocyte DNAs. The same mutation was recently reported in a patient with 46,XX karyotype. Additionally, our patient is homozygous for the common polymorphism c507C-->T, while both parents are heterozygous.
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Proteínas de Grupo de Alta Mobilidade/genética , Osteocondrodisplasias/genética , Mutação Puntual , Fatores de Transcrição/genética , Pré-Escolar , Análise Mutacional de DNA , Transtornos do Desenvolvimento Sexual , Domínios HMG-Box/genética , Proteínas de Grupo de Alta Mobilidade/química , Humanos , Masculino , Pais , Fatores de Transcrição SOX9 , Fatores de Transcrição/química , TurquiaRESUMO
Left tibial agenesis, polysyndactyly with talipes equinovarus deformity and Grade IV vesicoureteral reflux of the right kidney are described in a 40-day-old male and an unrelated 1-month-old male, is also reported with right tibial agenesis, polysyndactyly with talipes equinovarus deformity and right kidney agenesis and left Grade V vesicoureteral reflux. No other pathology was recorded. Follow up at 1 year and 3 years, respectively, revealed normal motor and mental development. As this combination has been unpublished before, we believe that this a new syndrome.
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Rim/anormalidades , Sindactilia/diagnóstico , Tíbia/anormalidades , Humanos , Lactente , Nefropatias/diagnóstico , Masculino , Radiografia , Síndrome , Tíbia/diagnóstico por imagem , Refluxo Vesicoureteral/diagnósticoAssuntos
Artrite Juvenil/diagnóstico , Osteocondrodisplasias/diagnóstico , Artrite Juvenil/diagnóstico por imagem , Artrografia , Criança , Diagnóstico Diferencial , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/genética , TurquiaRESUMO
UNLABELLED: Thyroid function tests were carried out on 320 children with Down's syndrome aged between 5 d and 10 y. Thyroid function was normal in 230 patients (71.9%) and abnormal in 90 (28.1%). Six patients (1.8%) had primary congenital hypothyroidism, one patient had acquired hypothyroidism and two had transient hyperthyrotropinaemia of the newborn. Sixteen of the remaining 81 patients (25.3%) had compensated hypothyroidism with increased thyroid-stimulating hormone (TSH) levels (11-20 mU l(-1)). Their T4 levels were found to be either normal or close to the lower limit of normal. These cases were started on thyroxine therapy. Sixty-five of the 81 patients had a mild compensated hypothyroidism with mild TSH elevation (6-10 mU l(-1)). None of the patients had hyperthyroidism. The antithyroid antibodies were positive in the acquired hypothyroidism case. CONCLUSION: The prevalence of congenital hypothyroidism was 1.8% in children with Down's syndrome while 25.3% of them had compensated hypothyroidism. It is suggested that Down's syndrome patients with normal thyroid functions and those with compensated hypothyroidism should be followed annually and every 3 mo, respectively. Besides congenital hypothyroidism cases, those with TSH levels between 11 and 20 mU l(-1) may benefit from treatment with low-dose thyroxine.
Assuntos
Síndrome de Down/complicações , Hipertireoxinemia/etiologia , Hipertireoxinemia/fisiopatologia , Hipotireoidismo/etiologia , Hipotireoidismo/fisiopatologia , Glândula Tireoide/fisiopatologia , Criança , Pré-Escolar , Hipotireoidismo Congênito , Síndrome de Down/sangue , Síndrome de Down/fisiopatologia , Feminino , Seguimentos , Humanos , Hipertireoxinemia/congênito , Lactente , Recém-Nascido , Masculino , Testes de Função Tireóidea , Glândula Tireoide/anormalidades , Glândula Tireoide/crescimento & desenvolvimento , Tireotropina/sangueRESUMO
Disorganization of the neurofilament network is a prominent feature of several neurodegenerative disorders including amyotrophic lateral sclerosis (ALS), infantile spinal muscular atrophy and axonal Charcot-Marie-Tooth disease. Giant axonal neuropathy (GAN, MIM 256850), a severe, autosomal recessive sensorimotor neuropathy affecting both the peripheral nerves and the central nervous system, is characterized by neurofilament accumulation, leading to segmental distension of the axons. GAN corresponds to a generalized disorganization of the cytoskeletal intermediate filaments (IFs), to which neurofilaments belong, as abnormal aggregation of multiple tissue-specific IFs has been reported: vimentin in endothelial cells, Schwann cells and cultured skin fibroblasts, and glial fibrillary acidic protein (GFAP) in astrocytes. Keratin IFs also seem to be alterated, as most patients present characteristic curly or kinky hairs. We report here identification of the gene GAN, which encodes a novel, ubiquitously expressed protein we have named gigaxonin. We found one frameshift, four nonsense and nine missense mutations in GAN of GAN patients. Gigaxonin is composed of an amino-terminal BTB (for Broad-Complex, Tramtrack and Bric a brac) domain followed by a six kelch repeats, which are predicted to adopt a beta-propeller shape. Distantly related proteins sharing a similar domain organization have various functions associated with the cytoskeleton, predicting that gigaxonin is a novel and distinct cytoskeletal protein that may represent a general pathological target for other neurodegenerative disorders with alterations in the neurofilament network.
Assuntos
Anormalidades Múltiplas/genética , Axônios/patologia , Cromossomos Humanos Par 16/genética , Proteínas do Citoesqueleto/genética , Cabelo/patologia , Neuropatia Hereditária Motora e Sensorial/genética , Proteínas do Tecido Nervoso/genética , Doenças Neurodegenerativas/genética , Alelos , Sequência de Aminoácidos , Doença de Charcot-Marie-Tooth/classificação , Doença de Charcot-Marie-Tooth/genética , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/deficiência , Proteínas do Citoesqueleto/fisiologia , Análise Mutacional de DNA , DNA Complementar/genética , Éxons/genética , Mutação da Fase de Leitura , Heterogeneidade Genética , Genótipo , Neuropatia Hereditária Motora e Sensorial/patologia , Neuropatia Hereditária Motora e Sensorial/veterinária , Humanos , Dados de Sequência Molecular , Família Multigênica , Proteínas do Tecido Nervoso/deficiência , Doenças Neurodegenerativas/patologia , Proteínas de Neurofilamentos/deficiência , Proteínas de Neurofilamentos/genética , Mutação Puntual , Estrutura Terciária de Proteína , Sequências Repetitivas de Aminoácidos , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Relação Estrutura-AtividadeRESUMO
The autosomal recessive form of Robinow syndrome (RRS; MIM 268310) is a severe skeletal dysplasia with generalized limb bone shortening, segmental defects of the spine, brachydactyly and a dysmorphic facial appearance. We previously mapped the gene mutated in RRS to chromosome 9q22 (ref. 4), a region that overlaps the locus for autosomal dominant brachydactyly type B (refs 5,6). The recent identification of ROR2, encoding an orphan receptor tyrosine kinase, as the gene mutated in brachydactyly type B (BDB1; ref. 7) and the mesomelic dwarfing in mice homozygous for a lacZ and/or a neo insertion into Ror2 (refs 8,9) made this gene a candidate for RRS. Here we report homozygous missense mutations in both intracellular and extracellular domains of ROR2 in affected individuals from 3 unrelated consanguineous families, and a nonsense mutation that removes the tyrosine kinase domain and all subsequent 3' regions of the gene in 14 patients from 7 families from Oman. The nature of these mutations suggests that RRS is caused by loss of ROR2 activity. The identification of mutations in three distinct domains (containing Frizzled-like, kringle and tyrosine kinase motifs) indicates that these are all essential for ROR2 function.