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2.
Clin Dysmorphol ; 28(3): 137-141, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30789376

RESUMO

Rubinstein-Taybi syndrome (RSTS) is a rare dominant disorder with intellectual disability, postnatal growth deficiency, and multiple congenital anomalies. Approximately 50-70% of the patients have a mutation in the CREBBP gene (RSTS1) and 5-10% display an EP300 gene mutation (RSTS2). Craniospinal abnormalities such as microcranium, scoliosis, and lordosis are frequent findings in RSTS1, but malformations of the brain or spinal cord are seen only occasionally. Here, we report on a 3-year-old boy with facial abnormalities of RSTS, broad thumbs and halluces, developmental delay, autistic features, cerebellar underdevelopment, and a neural tube defect. Molecular diagnostic of the CREBBP and EP300 genes showed a heterozygous 17-bp deletion (c.5698_5714del AAGGCAGCAGGCCAGGT) in exon 31 of the EP300 gene. Findings underline that small (hypoplastic) cerebellum and neural tube defects belong to the phenotypic spectrum not only of RSTS1 but also of RSTS2. Based on the literature and this observation, we recommend that each individual with RSTS2 should be closely evaluated for neural axis and craniovertebral junction anomalies, and where appropriate, neuroimaging studies should be considered. Our frequency estimate of ~ 6% occult or overt neural tube defects in RSTS2 could represent an underestimate.

3.
Eur J Med Genet ; : 103613, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30677517

RESUMO

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV (HSAN-IV), is a rare and severe autosomal recessive disorder. We report on an adult female patient whose clinical findings during childhood were not recognized as CIPA. There was neither complete anhidrosis nor a recognizable sensitivity to heat. Tumorlike swellings of many joints and skeletal signs of Charcot neuropathy developed in adolescence which, together with a history of self-mutilation, led to a clinical suspicion of CIPA confirmed by identification of a novel homozygous variant c.1795G > T in the NTRK1 gene in blood lymphocytes. Both parents were heterozygous for the mutation. The variant predicts a premature stop codon (p.Gly599Ter) and thus represents a pathogenic variant; the first reported in the Southeastern European population.

4.
Hum Mol Genet ; 27(8): 1343-1352, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29432577

RESUMO

CHARGE syndrome is an autosomal dominant malformation disorder caused by heterozygous loss of function mutations in the chromatin remodeler CHD7. Chd7 regulates the expression of Sema3a, which also contributes to the pathogenesis of Kallmann syndrome, a heterogeneous condition with the typical features hypogonadotropic hypogonadism and an impaired sense of smell. Both features are common in CHARGE syndrome suggesting that SEMA3A may provide a genetic link between these syndromes. Indeed, we find evidence that SEMA3A plays a role in the pathogenesis of CHARGE syndrome. First, Chd7 is enriched at the Sema3a promotor in neural crest cells and loss of function of Chd7 inhibits Sema3a expression. Second, using a Xenopus CHARGE model, we show that human SEMA3A rescues Chd7 loss of function. Third, to elucidate if SEMA3A mutations in addition to CHD7 mutations also contribute to the severity of the CHARGE phenotype, we screened 31 CHD7-positive patients and identified one patient with a heterozygous non-synonymous SEMA3A variant, c.2002A>G (p.I668V). By analyzing protein expression and processing, we did not observe any differences of the p.I668V variant compared with wild-type SEMA3A, while a pathogenic SEMA3A variant p.R66W recently described in a patient with Kallmann syndrome did affect protein secretion. Furthermore, the p.I668V variant, but not the pathogenic p.R66W variant, rescues Chd7 loss of function in Xenopus, indicating that the p.I668V variant is likely benign. Thus, SEMA3A is part of an epigenetic loop that plays a role in the pathogenesis of CHARGE syndrome, however, it seems not to act as a common direct modifier.

6.
Orphanet J Rare Dis ; 13(1): 23, 2018 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-29373990

RESUMO

BACKGROUND: Many of the genetic childhood disorders leading to death in the pre- or neonatal period or during early childhood follow autosomal recessive modes of inheritance and bear specific challenges for genetic counseling and prenatal diagnostics. Parents are carriers but clinically unaffected, and diseases are rare but have recurrence risks of 25% in the same family. Often, affected children (or fetuses) die before a genetic diagnosis can be established, post-mortem analysis and phenotypic descriptions are insufficient and DNA from affected fetuses or children is not available for later analysis. A genetic diagnosis showing biallelic causative mutations is, however, the requirement for targeted carrier testing in parents and prenatal and preimplantation genetic diagnosis in further pregnancies. METHODS: We undertook targeted next-generation sequencing (NGS) for carrier screening of autosomal recessive lethal disorders in 8 consanguineous and 5 non-consanguineous couples with one or more affected children. We searched for heterozygous variants (non-synonymous coding or splice variants) in parents' DNA, using a set of 430 genes known to be causative for rare autosomal recessive diseases with poor prognosis, and then filtering for variants present in genes overlapping in both partners. Putative pathogenic variants were tested for cosegregation in affected fetuses or children where material was available. RESULTS: The diagnosis for the premature death in children was established in 5 of the 13 couples. Out of the 8 couples in which no causative diagnosis could be established 4 consented to undergo further analysis, in two of those a potentially causative variant in a novel candidate gene was identified. CONCLUSIONS: For the families in whom causative variants could be identified, these may now be used for prenatal and preimplantation genetic diagnostics. Our data show that NGS based gene panel sequencing of selected genes involved in lethal autosomal recessive disorders is an effective tool for carrier screening in parents and for the identification of recessive gene defects and offers the possibility of prenatal and preimplantation genetic diagnosis in further pregnancies in families that have experienced deaths in early childhood and /or multiple abortions.

7.
Hum Genet ; 137(2): 111-127, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29305691

RESUMO

Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorineural hearing impairment (CAPOS) is a rare clinically distinct syndrome caused by a single dominant missense mutation, c.2452G>A, p.Glu818Lys, in ATP1A3, encoding the neuron-specific alpha subunit of the Na+/K+-ATPase α3. Allelic mutations cause the neurological diseases rapid dystonia Parkinsonism and alternating hemiplegia of childhood, disorders which do not encompass hearing or visual impairment. We present detailed clinical phenotypic information in 18 genetically confirmed patients from 11 families (10 previously unreported) from Denmark, Sweden, UK and Germany indicating a specific type of hearing impairment-auditory neuropathy (AN). All patients were clinically suspected of CAPOS and had hearing problems. In this retrospective analysis of audiological data, we show for the first time that cochlear outer hair cell activity was preserved as shown by the presence of otoacoustic emissions and cochlear microphonic potentials, but the auditory brainstem responses were grossly abnormal, likely reflecting neural dyssynchrony. Poor speech perception was observed, especially in noise, which was beyond the hearing level obtained in the pure tone audiograms in several of the patients presented here. Molecular modelling and in vitro electrophysiological studies of the specific CAPOS mutation were performed. Heterologous expression studies of α3 with the p.Glu818Lys mutation affects sodium binding to, and release from, the sodium-specific site in the pump, the third ion-binding site. Molecular dynamics simulations confirm that the structure of the C-terminal region is affected. In conclusion, we demonstrate for the first time evidence for auditory neuropathy in CAPOS syndrome, which may reflect impaired propagation of electrical impulses along the spiral ganglion neurons. This has implications for diagnosis and patient management. Auditory neuropathy is difficult to treat with conventional hearing aids, but preliminary improvement in speech perception in some patients suggests that cochlear implantation may be effective in CAPOS patients.

8.
Am J Med Genet A ; 176(3): 668-675, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29341480

RESUMO

The cutis laxa syndromes are multisystem disorders that share loose redundant inelastic and wrinkled skin as a common hallmark clinical feature. The underlying molecular defects are heterogeneous and 13 different genes have been involved until now, all of them being implicated in elastic fiber assembly. We provide here molecular and clinical characterization of three unrelated patients with a very rare phenotype associating cutis laxa, facial dysmorphism, severe growth retardation, hyperostotic skeletal dysplasia, and intellectual disability. This disorder called Lenz-Majewski syndrome (LMS) is associated with gain of function mutations in PTDSS1, encoding an enzyme involved in phospholipid biosynthesis. This report illustrates that LMS is an unequivocal cutis laxa syndrome and expands the clinical and molecular spectrum of this group of disorders. In the neonatal period, brachydactyly and facial dysmorphism are two early distinctive signs, later followed by intellectual disability and hyperostotic skeletal dysplasia with severe dwarfism allowing differentiation of this condition from other cutis laxa phenotypes. Further studies are needed to understand the link between PTDSS1 and extra cellular matrix assembly.

9.
Mol Syndromol ; 8(4): 172-178, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28690482

RESUMO

Barber-Say syndrome (BSS) and ablepharon-macrostomia syndrome (AMS) are infrequently reported congenital malformation disorders caused by mutations in the TWIST2 gene. Both are characterized by abnormalities in ectoderm-derived structures and cause a very unusual morphology of mainly the face in individuals with otherwise normal cognition and normal physical functioning. We studied the impact that the presence of BSS and AMS has on psychosocial functioning of affected individuals and their families, using their point of view to start with. We tabulated frequently asked questions from affected individuals and families, and a parent of an affected child and an affected adult woman offered personal testimonies. We focused on perception of illness, body satisfaction, and the consequences for an otherwise normal individual who has a disorder that interferes with body image. The importance of paying particular attention to the management of both the physical appearance and the consequences of these entities on the quality of life is stressed by the affected individuals themselves.

12.
Am J Med Genet A ; 170(12): 3069-3082, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27648933

RESUMO

Rubinstein-Taybi syndrome (RSTS) is a developmental disorder characterized by a typical face and distal limbs abnormalities, intellectual disability, and a vast number of other features. Two genes are known to cause RSTS, CREBBP in 60% and EP300 in 8-10% of clinically diagnosed cases. Both paralogs act in chromatin remodeling and encode for transcriptional co-activators interacting with >400 proteins. Up to now 26 individuals with an EP300 mutation have been published. Here, we describe the phenotype and genotype of 42 unpublished RSTS patients carrying EP300 mutations and intragenic deletions and offer an update on another 10 patients. We compare the data to 308 individuals with CREBBP mutations. We demonstrate that EP300 mutations cause a phenotype that typically resembles the classical RSTS phenotype due to CREBBP mutations to a great extent, although most facial signs are less marked with the exception of a low-hanging columella. The limb anomalies are more similar to those in CREBBP mutated individuals except for angulation of thumbs and halluces which is very uncommon in EP300 mutated individuals. The intellectual disability is variable but typically less marked whereas the microcephaly is more common. All types of mutations occur but truncating mutations and small rearrangements are most common (86%). Missense mutations in the HAT domain are associated with a classical RSTS phenotype but otherwise no genotype-phenotype correlation is detected. Pre-eclampsia occurs in 12/52 mothers of EP300 mutated individuals versus in 2/59 mothers of CREBBP mutated individuals, making pregnancy with an EP300 mutated fetus the strongest known predictor for pre-eclampsia. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteína de Ligação a CREB/genética , Proteína p300 Associada a E1A/genética , Pré-Eclâmpsia/genética , Síndrome de Rubinstein-Taybi/genética , Adulto , Montagem e Desmontagem da Cromatina/genética , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Pré-Eclâmpsia/fisiopatologia , Gravidez , Síndrome de Rubinstein-Taybi/patologia , Deleção de Sequência
14.
Epigenetics ; 11(2): 120-31, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26949839

RESUMO

Constitutive epimutations of tumor suppressor genes are increasingly considered as cancer predisposing factors equally to sequence mutations. In light of the emerging role of the microenvironment for cancer predisposition, initiation, and progression, we aimed to characterize the consequences of a BRCA1 epimutation in cells of mesenchymal origin. We performed a comprehensive molecular and cellular comparison of primary dermal fibroblasts taken from a monozygous twin pair discordant for recurrent cancers and BRCA1 epimutation, whose exceptional clinical case we previously reported in this journal. Comparative transcriptome analysis identified differential expression of extracellular matrix-related genes and pro-tumorigenic growth factors, such as collagens and CXC chemokines. Moreover, genes known to be key markers of so called cancer-associated fibroblasts (CAFs), such as ACTA2, FAP, PDPN, and TNC, were upregulated in fibroblasts of the affected twin (BRCA1(mosMe)) in comparison to those of the healthy twin (BRCA1(wt)). Further analyses detected CAF-typical cellular features, including an elevated growth rate, enhanced migration, altered actin architecture and increased production of ketone bodies in BRCA1(mosMe) fibroblasts compared to BRCA1(wt) fibroblasts. In addition, conditioned medium of BRCA1(mosMe) fibroblasts was more potent than conditioned medium of BRCA1(wt) fibroblasts to promote cell proliferation in an epithelial and a cancer cell line. Our data demonstrate, that a CAF-like state is not an exclusive feature of tumor-associated tissue but also exists in healthy tissue with tumor suppressor deficiency. The naturally occurring phenomenon of twin fibroblasts differing in their BRCA1 methylation status revealed to be a unique powerful tool for exploring tumor suppressor deficiency-related changes in healthy tissue, reinforcing their significance for cancer predisposition.


Assuntos
Proteína BRCA1/genética , Metilação de DNA , Fibroblastos/citologia , Mutação , Adulto , Linhagem Celular Tumoral , Células Cultivadas , Meios de Cultivo Condicionados , Citocinas/genética , Proteínas da Matriz Extracelular/genética , Feminino , Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica , Genes Homeobox , Genes Supressores de Tumor , Haploinsuficiência , Humanos , Corpos Cetônicos/metabolismo , Recidiva Local de Neoplasia/genética , Análise de Sequência com Séries de Oligonucleotídeos , Pele/citologia , Transcriptoma , Gêmeos
15.
Clin Dysmorphol ; 25(2): 50-3, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26882220

RESUMO

The ectrodactyly, ectodermal dysplasia, and cleft lip/palate syndrome 3 (EEC3; OMIM #604292), the Rapp-Hodgkin syndrome (RHS), and various other syndromes are caused by mutations in the TP63 gene, which encodes a p53-like transcription factor. Here, we report on a woman aged 37 years and her daughter aged 3 years with the previously reported c.1028G>A (p.Arg343Gln) mutation in exon 8 of TP63. The mother lacked ectrodactyly, indicating a diagnosis of RHS, whereas the girl presented with all three major features (ectrodactyly, ectodermal dysplasia, clefting) and different minor features (including small and brittle nails, and recurrent conjunctivitis believed to be because of stenotic and blocked nasolacrimal ducts) of the EEC3 syndrome. The EEC and EEC-like syndromes are usually distinguished on the basis of the clinical findings; however, these syndromes show a huge variability in features because of variable expressivity and incomplete penetrance, making the correct clinical assignment difficult. In EEC3 syndrome and RHS, a clustering of mutations in the different domains of TP63 can be observed. Our findings indicate the clinical variability with TP63 mutations and underline that in the case of two syndromes being clinically possible in a patient, the final diagnosis should be assigned only after molecular diagnostics.


Assuntos
Fenda Labial/diagnóstico , Fenda Labial/genética , Fissura Palatina/diagnóstico , Fissura Palatina/genética , Displasia Ectodérmica/diagnóstico , Displasia Ectodérmica/genética , Dedos/anormalidades , Deformidades Congênitas do Pé/diagnóstico , Deformidades Congênitas do Pé/genética , Deformidades Congênitas da Mão/diagnóstico , Deformidades Congênitas da Mão/genética , Mutação , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Adulto , Alelos , Substituição de Aminoácidos , Pré-Escolar , Éxons , Facies , Feminino , Heterozigoto , Humanos , Linhagem , Fenótipo
16.
Ear Hear ; 37(4): e238-46, 2016 Jul-Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26849169

RESUMO

OBJECTIVE: PDZD7 was identified in 2009 in a family with apparent nonsyndromic sensorineural hearing loss. However, subsequent clinical reports have associated PDZD7 with digenic Usher syndrome, the most common cause of deaf-blindness, or as a modifier of retinal disease. No further reports have validated this gene for nonsyndromic hearing loss, intuitively calling correct genotype-phenotype association into question. This report describes a validating second case for biallelic mutations in PDZD7 causing nonsyndromic mild to severe sensorineural hearing loss. It also provides detailed audiometric and ophthalmologic data excluding Usher syndrome in both the present proband (proband 1) and the first proband described in 2009 (proband 2). DESIGN: Proband 1 was sequenced using a custom-designed next generation sequencing panel consisting of 151 deafness genes. Bioinformatics analysis and filtering disclosed two PDZD7 sequence variants (c.1648C>T, p.Q550* and c.2107del, p.S703Vfs*20). Segregation testing followed in the family. For both probands, audiograms were collected and analyzed for progressive hearing loss and detailed ophthalmic evaluations were performed including electroretinography. RESULTS: Proband 1 demonstrated a prelingual, nonsyndromic, sensorineural hearing loss that progressed in the higher frequencies between 4 and 9 years old. PDZD7 segregation analysis confirmed biallelic inheritance (compound heterozygosity). Mutation analysis determined the c.1648C>T mutation as novel and reported the c.2107del deletion as rs397516633 with a calculated minor allele frequency of 0.000018. Clinical evaluation spanning well over a decade in proband 2 disclosed bilateral, nonprogressive hearing loss. Both probands showed healthy retinas, excluding Usher syndrome-like changes in the eye. CONCLUSIONS: PDZD7 is confirmed as a bona fide autosomal recessive nonsyndromic hearing loss gene. In both probands, there was no evidence of impaired vision or ophthalmic pathology. As the current understanding of PDZD7 mutations bridge Mendelian and complex phenotypes, the authors recommend careful variant interpretation, since PDZD7 is one of many genes associated with both Usher syndrome and autosomal recessive nonsyndromic hearing loss. Additional reports are required for understanding the complete phenotypic spectrum of this gene, including the possibility of high-frequency progression, as well as noise-induced hearing loss susceptibility in adult carriers. This report rules out all forms of Usher syndrome with an onset before 12 and 15 years old in probands 1 and 2, respectively. However, due to the young ages of the probands, this report is uninformative regarding older patients.


Assuntos
Proteínas de Transporte/genética , Perda Auditiva Neurossensorial/genética , Adolescente , Alelos , Audiometria de Tons Puros , Criança , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Predisposição Genética para Doença , Heterozigoto , Humanos , Masculino , Mutação , Emissões Otoacústicas Espontâneas , Análise de Sequência de DNA
17.
Hum Mol Genet ; 24(23): 6699-710, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26362256

RESUMO

Patients with 46,XY gonadal dysgenesis (GD) exhibit genital anomalies, which range from hypospadias to complete male-to-female sex reversal. However, a molecular diagnosis is made in only 30% of cases. Heterozygous mutations in the human FGFR2 gene cause various craniosynostosis syndromes including Crouzon and Pfeiffer, but testicular defects were not reported. Here, we describe a patient whose features we would suggest represent a new FGFR2-related syndrome, craniosynostosis with XY male-to-female sex reversal or CSR. The craniosynostosis patient was chromosomally XY, but presented as a phenotypic female due to complete GD. DNA sequencing identified the FGFR2c heterozygous missense mutation, c.1025G>C (p.Cys342Ser). Substitution of Cys342 by Ser or other amino acids (Arg/Phe/Try/Tyr) has been previously reported in Crouzon and Pfeiffer syndrome. We show that the 'knock-in' Crouzon mouse model Fgfr2c(C342Y/C342Y) carrying a Cys342Tyr substitution displays XY gonadal sex reversal with variable expressivity. We also show that despite FGFR2c-Cys342Tyr being widely considered a gain-of-function mutation, Cys342Tyr substitution in the gonad leads to loss of function, as demonstrated by sex reversal in Fgfr2c(C342Y/-) mice carrying the knock-in allele on a null background. The rarity of our patient suggests the influence of modifier genes which exacerbated the testicular phenotype. Indeed, patient whole exome analysis revealed several potential modifiers expressed in Sertoli cells at the time of testis determination in mice. In summary, this study identifies the first FGFR2 mutation in a 46,XY GD patient. We conclude that, in certain rare genetic contexts, maintaining normal levels of FGFR2 signaling is important for human testis determination.


Assuntos
Craniossinostoses/genética , Disgenesia Gonadal 46 XY/genética , Mutação de Sentido Incorreto , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Adolescente , Animais , Craniossinostoses/metabolismo , Análise Mutacional de DNA , Modelos Animais de Doenças , Feminino , Técnicas de Introdução de Genes , Humanos , Masculino , Camundongos , Camundongos Mutantes , Síndrome
18.
Mol Genet Metab ; 116(3): 163-70, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26260076

RESUMO

The conserved oligomeric Golgi (COG) complex consists of eight subunits and plays a crucial role in Golgi trafficking and positioning of glycosylation enzymes. Mutations in all COG subunits, except subunit 3, have been detected in patients with congenital disorders of glycosylation (CDG) of variable severity. So far, 3 families with a total of 10 individuals with biallelic COG6 mutations have been described, showing a broad clinical spectrum. Here we present 7 additional patients with 4 novel COG6 mutations. In spite of clinical variability, we delineate the core features of COG6-CDG i.e. liver involvement (9/10), microcephaly (8/10), developmental disability (8/10), recurrent infections (7/10), early lethality (6/10), and hypohidrosis predisposing for hyperthermia (6/10) and hyperkeratosis (4/10) as ectodermal signs. Regarding all COG6-related disorders a genotype-phenotype correlation can be discerned ranging from deep intronic mutations found in Shaheen syndrome as the mildest form to loss-of-function mutations leading to early lethal CDG phenotypes. A comparison with other COG deficiencies suggests ectodermal changes to be a hallmark of COG6-related disorders. Our findings aid clinical differentiation of this complex group of disorders and imply subtle functional differences between the COG complex subunits.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/genética , Defeitos Congênitos da Glicosilação/genética , Defeitos Congênitos da Glicosilação/fisiopatologia , Complexo de Golgi/genética , Adolescente , Criança , Defeitos Congênitos da Glicosilação/complicações , Feminino , Estudos de Associação Genética , Glicosilação , Complexo de Golgi/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino , Microcefalia/etiologia , Dados de Sequência Molecular , Mutação , Fenótipo , Adulto Jovem
19.
EBioMedicine ; 2(2): 158-64, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26137554

RESUMO

BACKGROUND: Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T. METHODS: We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autologous vein reconstruction for arterial occlusive disease as controls. We compared the frequencies of c.677C>T and another polymorphism of MTHFR, c.1298A>C, with morphology and types of complicated disease. Morphology was recorded as a trunk or perforator type and peripheral congestive complication was defined as chronic venous insufficiency (CEAP C3-6) associated with edema and skin manifestations. FINDINGS: Multivariate analysis of genotypes for c.677C>T and c.1298A>C indicated that c.677C>T was associated significantly with the trunk phenotype (43/53 patients, 81%, p < 0.01), while c.1298A>C was associated significantly with the perforator phenotype (18/24 patients, 75%, p < 0.01) of primary varicose veins. Accordingly, when both c.677C>T and c.1298A>C displayed a heterozygous genotype, the patients were more likely to present with both phenotypes. Additionally, c.1298A>C was found to be strongly linked to the congestive complication (34/51 patients, 67%, p < 0.01). INTERPRETATION: Both polymorphisms of MTHFR may be involved in the morphological specification of primary varicose veins and contribute to the development of complicated disease. FUNDING: None.


Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Varizes , Doença Crônica , Feminino , Humanos , Masculino , Varizes/enzimologia , Varizes/genética , Varizes/patologia , Varizes/fisiopatologia
20.
Am J Hum Genet ; 97(1): 99-110, 2015 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-26119818

RESUMO

Ablepharon macrostomia syndrome (AMS) and Barber-Say syndrome (BSS) are rare congenital ectodermal dysplasias characterized by similar clinical features. To establish the genetic basis of AMS and BSS, we performed extensive clinical phenotyping, whole exome and candidate gene sequencing, and functional validations. We identified a recurrent de novo mutation in TWIST2 in seven independent AMS-affected families, as well as another recurrent de novo mutation affecting the same amino acid in ten independent BSS-affected families. Moreover, a genotype-phenotype correlation was observed, because the two syndromes differed based solely upon the nature of the substituting amino acid: a lysine at TWIST2 residue 75 resulted in AMS, whereas a glutamine or alanine yielded BSS. TWIST2 encodes a basic helix-loop-helix transcription factor that regulates the development of mesenchymal tissues. All identified mutations fell in the basic domain of TWIST2 and altered the DNA-binding pattern of Flag-TWIST2 in HeLa cells. Comparison of wild-type and mutant TWIST2 expressed in zebrafish identified abnormal developmental phenotypes and widespread transcriptome changes. Our results suggest that autosomal-dominant TWIST2 mutations cause AMS or BSS by inducing protean effects on the transcription factor's DNA binding.


Assuntos
Anormalidades Múltiplas/genética , Anormalidades do Olho/genética , Doenças Palpebrais/genética , Hirsutismo/genética , Hipertelorismo/genética , Hipertricose/genética , Macrostomia/genética , Modelos Moleculares , Fenótipo , Proteínas Repressoras/genética , Anormalidades da Pele/genética , Proteína 1 Relacionada a Twist/genética , Anormalidades Múltiplas/patologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Imunoprecipitação da Cromatina , Exoma/genética , Anormalidades do Olho/patologia , Doenças Palpebrais/patologia , Células HeLa , Hirsutismo/patologia , Humanos , Hipertelorismo/patologia , Hipertricose/patologia , Macrostomia/patologia , Microscopia Eletrônica , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , Conformação Proteica , Proteínas Repressoras/química , Análise de Sequência de DNA , Anormalidades da Pele/patologia , Proteína 1 Relacionada a Twist/química , Peixe-Zebra
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