Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 130
Filtrar
1.
J Clin Pathol ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38981663

RESUMO

AIMS: Analysis of the F8 gene helps predict the risk of developing factor VIII (FVIII) inhibitors and the depth of phenotype in haemophilia A (HA) patients. Since data in Southeast Asian countries remain scarce, we aim to study F8 variation correlated with HA phenotypes in Thailand. METHODS: Thai patients with HA were enrolled from seven haemophilia treatment centres during 2022-2023. Using peripheral blood DNA, inverse shifting-polymerase chain reaction (IS-PCR) for F8-intron 22 inversion (Inv22) and F8-intron 1 inversion (Inv1) was performed. Whole exome sequencing (WES) was explored in cases without Inv22/Inv1. RESULTS: Of 124 patients with HA, 91.9% were detected with a causative F8 variant, including Inv22 (30.6%), Inv1 (1.6%), missense (23.4%), nonsense (16.9%) and small insertion/deletion (16.1%) mutations. Inv22, small insertion/deletion and nonsense were associated with severe HA, compared with missense variants, by the ORs of 13.9 (95% CI, 4.2 to 56.7), 14.7 (95% CI, 3.4 to 104.7) and 15.6 (95% CI, 3.6 to 110.2), respectively. While nonsense variants affecting the light chain increased the risk of developing FVIII inhibitors (OR, 6.8; 95% CI, 1.5 to 32.6) compared with the low-risk (small insertion/deletion, missense and splice-site) variants. Twelve patients (9.7%) harboured novel F8 variants, comprising five missense (p.Pro540Leu, p.Ser564Pro, p.Leu668Pro, p.Ala1721Glu, p.His2024Pro), five small insertion/deletion (p.Val502SerfsTer13, p.Ile522PhefsTer13, p.Phe992LysfsTer11, p.Leu1223PhefsTer18, c.6427_6429+3delATGGTA) and one nonsense mutations (p.Glu1292Ter). CONCLUSIONS: IS-PCR followed by WES successfully assesses F8 alterations in most HA cases. With several unique variants, severe HA in Thailand is considerably caused by Inv22, small insertion/deletion and nonsense, whereas missense variants are more responsible for nonsevere HA phenotypes.

3.
Clin Exp Reprod Med ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38853127

RESUMO

Errors in human DNA may cause genetic disorders. Technological developments have raised hopes for reducing the risks of genetic inheritance among married couples who have a history of such disorders. Among the developments in reproductive health technology that reduce those risks is the in vitro fertilization (IVF) process. This review aimed to describe the current strategies using IVF and preimplantation genetic testing (PGT), which would be effective for couples with genetic disorders to have healthy offspring. The literature review included full-text, open-access research articles from ScienceDirect, PubMed, and Google Scholar that were published between 2013 and 2023, with 65 articles obtained from various journals. The keywords were "in vitro fertilization," "reproductive genetic disorders," "PGT-A," "PGT-M," "PGT-SR," and "oocyte donor." A total of 46 articles were selected as the most relevant to the review topic, and the results show that the IVF process can be an option for couples with a history of genetic disorders. Several additional procedures can be performed following IVF, such as oocyte donation and PGT, to help couples who want to have offspring without transmitting their genetic disorders. IVF can be an option for couples who have or carry genetic disorders. With IVF, couples can undertake several procedures such as oocyte donation and PGT for aneuploidy, monogenic disorders, or structural rearrangement.

4.
J Med Genet ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849204

RESUMO

INTRODUCTION: Tonne-Kalscheuer syndrome (TOKAS) is a recessive X-linked multiple congenital anomaly disorder caused by RLIM variations. Of the 41 patients reported, only 7 antenatal cases were described. METHOD: After the antenatal diagnosis of TOKAS by exome analysis in a family followed for over 35 years because of multiple congenital anomalies in five male fetuses, a call for collaboration was made, resulting in a cohort of 11 previously unpublished cases. RESULTS: We present a TOKAS antenatal cohort, describing 11 new cases in 6 French families. We report a high frequency of diaphragmatic hernia (9 of 11), differences in sex development (10 of 11) and various visceral malformations. We report some recurrent dysmorphic features, but also pontocerebellar hypoplasia, pre-auricular skin tags and olfactory bulb abnormalities previously unreported in the literature. Although no clear genotype-phenotype correlation has yet emerged, we show that a recurrent p.(Arg611Cys) variant accounts for 66% of fetal TOKAS cases. We also report two new likely pathogenic variants in RLIM, outside of the two previously known mutational hotspots. CONCLUSION: Overall, we present the first fetal cohort of TOKAS, describe the clinical features that made it a recognisable syndrome at fetopathological examination, and extend the phenotypical spectrum and the known genotype of this rare disorder.

5.
J Med Genet ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937076

RESUMO

BACKGROUND: Tatton-Brown-Rahman syndrome (TBRS; OMIM 615879), also known as DNA methyltransferase 3 alpha (DNMT3A)-overgrowth syndrome (DOS), was first described by Tatton-Brown in 2014. This syndrome is characterised by overgrowth, intellectual disability and distinctive facial features and is the consequence of germline loss-of-function variants in DNMT3A, which encodes a DNA methyltransferase involved in epigenetic regulation. Somatic variants of DNMT3A are frequently observed in haematological malignancies, including acute myeloid leukaemia (AML). To date, 100 individuals with TBRS with de novo germline variants have been described. We aimed to further characterise this disorder clinically and at the molecular level in a nationwide series of 24 French patients and to investigate the correlation between the severity of intellectual disability and the type of variant. METHODS: We collected genetic and medical information from 24 individuals with TBRS using a questionnaire released through the French National AnDDI-Rares Network. RESULTS: Here, we describe the first nationwide French cohort of 24 individuals with germline likely pathogenic/pathogenic variants in DNMT3A, including 17 novel variants. We confirmed that the main phenotypic features were intellectual disability (100% of individuals), distinctive facial features (96%) and overgrowth (87%). We highlighted novel clinical features, such as hypertrichosis, and further described the neurological features and EEG results. CONCLUSION: This study of a nationwide cohort of individuals with TBRS confirms previously published data and provides additional information and clarifies clinical features to facilitate diagnosis and improve care. This study adds value to the growing body of knowledge on TBRS and broadens its clinical and molecular spectrum.

7.
J Med Genet ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816193

RESUMO

BACKGROUND AND AIMS: Variants in ZFYVE19 underlie a disorder characterised by progressive portal fibrosis, portal hypertension and eventual liver decompensation. We aim to create an animal model to elucidate the pathogenic mechanism. METHODS: Zfyve19 knockout (Zfyve19-/- ) mice were generated and exposed to different liver toxins. Their livers were characterised at the tissue, cellular and molecular levels. Findings were compared with those in wild-type mice and in ZFYVE19-deficient patients. ZFYVE19 knockout and knockdown retinal pigment epithelial-1 cells and mouse embryonic fibroblasts were generated to study cell division and cell death. RESULTS: The Zfyve19-/- mice were normal overall, particularly with respect to hepatobiliary features. However, when challenged with α-naphthyl isothiocyanate, Zfyve19-/- mice developed changes resembling those in ZFYVE19-deficient patients, including elevated serum liver injury markers, increased numbers of bile duct profiles with abnormal cholangiocyte polarity and biliary fibrosis. Failure of cell division, centriole and cilia abnormalities, and increased cell death were observed in knockdown/knockout cells. Increased cell death and altered mRNA expression of cell death-related signalling pathways was demonstrated in livers from Zfyve19-/- mice and patients. Transforming growth factor-ß (TGF-ß) and Janus kinase-Signal Transducer and Activator of Transcription 3 (JAK-STAT3) signalling pathways were upregulated in vivo, as were chemokines such as C-X-C motif ligands 1, 10 and 12. CONCLUSIONS: Our findings demonstrated that ZFYVE19 deficiency is a ciliopathy with novel histological features. Failure of cell division with ciliary abnormalities and cell death activates macrophages and may thus lead to biliary fibrosis via TGF-ß pathway in the disease.

8.
J Med Genet ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38670634

RESUMO

BACKGROUND: Pontocerebellar hypoplasia (PCH) may present with supratentorial phenotypes and is often accompanied by microcephaly. Damaging mutations in the X-linked gene CASK produce self-limiting microcephaly with PCH in females but are often lethal in males. CASK deficiency leads to early degeneration of cerebellar granule cells but its role in other regions of the brain remains uncertain. METHOD: We generated a conditional Cask knockout mice and deleted Cask ubiquitously after birth at different times. We examined the clinical features in several subjects with damaging mutations clustered in the central part of the CASK protein. We have performed phylogenetic analysis and RT-PCR to assess the splicing pattern within the same protein region and performed in silico structural analysis to examine the effect of splicing on the CASK's structure. RESULT: We demonstrate that deletion of murine Cask after adulthood does not affect survival but leads to cerebellar degeneration and ataxia over time. Intriguingly, damaging hemizygous CASK mutations in boys who display microcephaly and cerebral dysfunction but without PCH are known. These mutations are present in two vertebrate-specific CASK exons. These exons are subject to alternative splicing both in forebrain and hindbrain. Inclusion of these exons differentially affects the molecular structure and hence possibly the function/s of the CASK C-terminus. CONCLUSION: Loss of CASK function disproportionately affects the cerebellum. Clinical data, however, suggest that CASK may have additional vertebrate-specific function/s that play a role in the mammalian forebrain. Thus, CASK has an ancient function shared between invertebrates and vertebrates as well as novel vertebrate-specific function/s.

9.
J Med Genet ; 61(7): 699-706, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38663984

RESUMO

BACKGROUND: Clubfoot, presenting as a rigid inward and downward turning of the foot, is one of the most common congenital musculoskeletal anomalies. The aetiology of clubfoot is poorly understood and variants in known clubfoot disease genes account for only a small portion of the heritability. METHODS: Exome sequence data were generated from 1190 non-syndromic clubfoot cases and their family members from multiple ethnicities. Ultra-rare variant burden analysis was performed comparing 857 unrelated clubfoot cases with European ancestry with two independent ethnicity-matched control groups (1043 in-house and 56 885 gnomAD controls). Additional variants in prioritised genes were identified in a larger cohort, including probands with non-European ancestry. Segregation analysis was performed in multiplex families when available. RESULTS: Rare variants in 29 genes were enriched in clubfoot cases, including PITX1 (a known clubfoot disease gene), HOXD12, COL12A1, COL9A3 and LMX1B. In addition, rare variants in posterior HOX genes (HOX9-13) were enriched overall in clubfoot cases. In total, variants in these genes were present in 8.4% (100/1190) of clubfoot cases with both European and non-European ancestry. Among these, 3 are de novo and 22 show variable penetrance, including 4 HOXD12 variants that segregate with clubfoot. CONCLUSION: We report HOXD12 as a novel clubfoot disease gene and demonstrate a phenotypic expansion of known disease genes (myopathy gene COL12A1, Ehlers-Danlos syndrome gene COL9A3 and nail-patella syndrome gene LMX1B) to include isolated clubfoot.


Assuntos
Pé Torto Equinovaro , Sequenciamento do Exoma , Proteínas de Homeodomínio , Feminino , Humanos , Masculino , Pé Torto Equinovaro/genética , Pé Torto Equinovaro/patologia , Exoma/genética , Predisposição Genética para Doença , Proteínas de Homeodomínio/genética , Linhagem , Fatores de Transcrição/genética
10.
Open Heart ; 11(1)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38569668

RESUMO

AIMS: Some patients with cardiac dystrophinopathy die suddenly. Whether such deaths are preventable by specific antiarrhythmic management or simply indicate heart failure overwhelming medical therapies is uncertain. The aim of this prospective, cohort study was to describe the occurrence and nature of cardiac arrhythmias recorded during prolonged continuous ECG rhythm surveillance in patients with established cardiac dystrophinopathy and relate them to abnormalities on cardiac MRI. METHODS AND RESULTS: A cohort of 10 patients (36.3 years; 3 female) with LVEF<40% due to Duchenne (3) or Becker muscular (4) dystrophy or Duchenne muscular dystrophy-gene carrying effects in females (3) were recruited, had cardiac MRI, ECG signal-averaging and ECG loop-recorder implants. All were on standard of care heart medications and none had prior history of arrhythmias.No deaths or brady arrhythmias occurred during median follow-up 30 months (range 13-35). Self-limiting episodes of asymptomatic tachyarrhythmia (range 1-29) were confirmed in 8 (80%) patients (ventricular only 2; ventricular and atrial 6). Higher ventricular arrhythmia burden correlated with extent of myocardial fibrosis (extracellular volume%, p=0.029; native T1, p=0.49; late gadolinium enhancement, p=0.49), but not with LVEF% (p=1.0) on MRI and atrial arrhythmias with left atrial dilatation. Features of VT episodes suggested various underlying arrhythmia mechanisms. CONCLUSIONS: The overall prevalence of arrhythmias was low. Even in such a small sample size, higher arrhythmia counts occurred in those with larger scar burden and greater ventricular volume, suggesting key roles for myocardial stretch as well as disease progression in arrhythmogenesis. These features overlap with the stage of left ventricular dysfunction when heart failure also becomes overt. The findings of this pilot study should help inform the design of a definitive study of specific antiarrhythmic management in dystrophinopathy. TRIAL REGISTRATION NUMBER: ISRCTN15622536.


Assuntos
Meios de Contraste , Insuficiência Cardíaca , Humanos , Feminino , Estudos Prospectivos , Estudos de Coortes , Projetos Piloto , Gadolínio , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiologia , Imageamento por Ressonância Magnética , Antiarrítmicos/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico
11.
J Med Genet ; 61(6): 503-519, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38471765

RESUMO

Rubinstein-Taybi syndrome (RTS) is an archetypical genetic syndrome that is characterised by intellectual disability, well-defined facial features, distal limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in either of two genes (CREBBP, EP300) which encode for the proteins CBP and p300, which both have a function in transcription regulation and histone acetylation. As a group of international experts and national support groups dedicated to the syndrome, we realised that marked heterogeneity currently exists in clinical and molecular diagnostic approaches and care practices in various parts of the world. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria for types of RTS (RTS1: CREBBP; RTS2: EP300), molecular investigations, long-term management of various particular physical and behavioural issues and care planning. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimisation of diagnostics and care.


Assuntos
Proteína de Ligação a CREB , Proteína p300 Associada a E1A , Síndrome de Rubinstein-Taybi , Síndrome de Rubinstein-Taybi/genética , Síndrome de Rubinstein-Taybi/diagnóstico , Síndrome de Rubinstein-Taybi/terapia , Humanos , Proteína de Ligação a CREB/genética , Proteína p300 Associada a E1A/genética , Consenso , Gerenciamento Clínico , Mutação
12.
J Med Genet ; 61(5): 469-476, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38458756

RESUMO

BACKGROUND: Marfan syndrome (MFS) is a multisystem disease with a unique combination of skeletal, cardiovascular and ocular features. Geleophysic/acromicric dysplasias (GPHYSD/ACMICD), characterised by short stature and extremities, are described as 'the mirror image' of MFS. The numerous FBN1 pathogenic variants identified in MFS are located all along the gene and lead to the same final pathogenic sequence. Conversely, in GPHYSD/ACMICD, the 28 known heterozygous FBN1 pathogenic variants all affect exons 41-42 encoding TGFß-binding protein-like domain 5 (TB5). METHODS: Since 1996, more than 5000 consecutive probands have been referred nationwide to our laboratory for molecular diagnosis of suspected MFS. RESULTS: We identified five MFS probands carrying distinct heterozygous pathogenic in-frame variants affecting the TB5 domain of FBN1. The clinical data showed that the probands displayed a classical form of MFS. Strikingly, one missense variant affects an amino acid that was previously involved in GPHYSD. CONCLUSION: Surprisingly, pathogenic variants in the TB5 domain of FBN1 can lead to two opposite phenotypes: GPHYSD/ACMICD and MFS, suggesting the existence of different pathogenic sequences with the involvement of tissue specificity. Further functional studies are ongoing to determine the precise role of this domain in the physiopathology of each disease.


Assuntos
Doenças do Desenvolvimento Ósseo , Deformidades Congênitas dos Membros , Síndrome de Marfan , Humanos , Doenças do Desenvolvimento Ósseo/genética , Fibrilina-1/genética , Síndrome de Marfan/genética , Síndrome de Marfan/patologia , Mutação
13.
Diabetes Metab J ; 48(3): 482-486, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38311059

RESUMO

Maternally inherited diabetes and deafness (MIDD) is a rare mitochondrial disorder primarily resulting from m.3243A>G mutation. The clinical characteristics of MIDD exhibit significant heterogeneity. Our study aims to delineate these characteristics and determine the potential correlation with m.3243A>G heteroplasmy levels. This retrospective, descriptive study encompassed patients with confirmed m.3243A>G mutation and diabetes mellitus at Seoul National University Hospital. Our cohort comprises 40 patients with MIDD, with a mean age at study enrollment of 33.3±12.9 years and an average % of heteroplasmy of 30.0%± 14.6% in the peripheral blood. The most prevalent comorbidity was hearing loss (90%), followed by albuminuria (61%), seizure (38%), and stroke (33%). We observed a significant negative correlation between % of heteroplasmy and age at diabetes diagnosis. These clinical features can aid in the suspicion of MIDD and further consideration of genetic testing for m.3243A>G mutation.


Assuntos
DNA Mitocondrial , Surdez , Doenças Mitocondriais , Mutação , Humanos , Feminino , Masculino , DNA Mitocondrial/genética , Estudos Retrospectivos , Adulto , República da Coreia/epidemiologia , Doenças Mitocondriais/genética , Doenças Mitocondriais/diagnóstico , Doenças Mitocondriais/epidemiologia , Pessoa de Meia-Idade , Surdez/genética , Adulto Jovem , Diabetes Mellitus/genética , Diabetes Mellitus/epidemiologia , Adolescente , Heteroplasmia , Perda Auditiva/genética , Diabetes Mellitus Tipo 2
14.
J Med Genet ; 61(5): 459-468, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38296632

RESUMO

BACKGROUND: Townes-Brocks syndrome (TBS) is a rare genetic disorder characterised by multiple malformations. Due to its phenotypic heterogeneity and rarity, diagnosis and recognition of TBS can be challenging and there has been a lack of investigation of patients with atypical TBS in large cohorts and delineation of their phenotypic characteristics. METHODS: We screened SALL1 and DACT1 variants using next-generation sequencing in the China Deafness Genetics Consortium (CDGC) cohort enrolling 20 666 unrelated hearing loss (HL) cases. Comprehensive clinical evaluations were conducted on seven members from a three-generation TBS family. Combining data from previously reported cases, we also provided a landscape of phenotypes and genotypes of patients with TBS. RESULTS: We identified five novel and two reported pathogenic/likely pathogenic (P/LP) SALL1 variants from seven families. Audiological features in patients differed in severity and binaural asymmetry. Moreover, previously undocumented malformations in the middle and inner ear were detected in one patient. By comprehensive clinical evaluations, we further provide evidence for the causal relationship between SALL1 variation and certain endocrine abnormalities. Penetrance analysis within familial contexts revealed incomplete penetrance among first-generation patients with TBS and a higher disease burden among their affected offspring. CONCLUSION: This study presents the first insight of genetic screening for patients with TBS in a large HL cohort. We broadened the phenotypic-genotypic spectrum of TBS and our results supported an underestimated prevalence of TBS. Due to the rarity and phenotypic heterogeneity of rare diseases, broader spectrum molecular tests, especially whole genome sequencing, can improve the situation of underdiagnosis and provide effective recommendations for clinical management.


Assuntos
Anormalidades Múltiplas , Anus Imperfurado , Perda Auditiva Neurossensorial , Polegar/anormalidades , Fatores de Transcrição , Humanos , Mutação , Fatores de Transcrição/genética , Síndrome , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Fenótipo , Proteínas Nucleares/genética , Proteínas Adaptadoras de Transdução de Sinal/genética
15.
J Med Genet ; 61(6): 590-594, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38228391

RESUMO

Background Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder caused by (epi)genetic alterations at 11p15. Because approximately 20% of patients test negative via molecular testing of peripheral blood leukocytes, the concept of Beckwith-Wiedemann spectrum (BWSp) was established to encompass a broader cohort with diverse and overlapping phenotypes. The prevalence of other overgrowth syndromes concealed within molecularly negative BWSp remains unexplored. Methods We conducted whole-exome sequencing (WES) on 69 singleton patients exhibiting molecularly negative BWSp. Variants were confirmed by Sanger sequencing or quantitative genomic PCR. We compared BWSp scores and clinical features between groups with classical BWS (cBWS), atypical BWS or isolated lateralised overgrowth (aBWS+ILO) and overgrowth syndromes identified via WES. Results Ten patients, one classified as aBWS and nine as cBWS, showed causative gene variants for Simpson-Golabi-Behmel syndrome (five patients), Sotos syndrome (two), Imagawa-Matsumoto syndrome (one), glycosylphosphatidylinositol biosynthesis defect 11 (one) or 8q duplication/9p deletion (one). BWSp scores did not distinguish between cBWS and other overgrowth syndromes. Birth weight and height in other overgrowth syndromes were significantly larger than in aBWS+ILO and cBWS, with varying intergroup frequencies of clinical features. Conclusion Molecularly negative BWSp encapsulates other syndromes, and considering both WES and clinical features may facilitate accurate diagnosis.


Assuntos
Síndrome de Beckwith-Wiedemann , Sequenciamento do Exoma , Humanos , Síndrome de Beckwith-Wiedemann/genética , Síndrome de Beckwith-Wiedemann/patologia , Síndrome de Beckwith-Wiedemann/diagnóstico , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Fenótipo , Transtornos do Crescimento/genética , Transtornos do Crescimento/patologia , Variação Genética , Mutação/genética
16.
J Med Genet ; 61(6): 549-552, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38272662

RESUMO

Fetal hydrops as detected by prenatal ultrasound usually carries a poor prognosis depending on the underlying aetiology. We describe the prenatal and postnatal clinical course of two unrelated female probands in whom de novo heterozygous missense variants in the planar cell polarity gene CELSR1 were detected using exome sequencing. Using several in vitro assays, we show that the CELSR1 p.(Cys1318Tyr) variant disrupted the subcellular localisation, affected cell-cell junction, impaired planar cell polarity signalling and lowered proliferation rate. These observations suggest that deleterious rare CELSR1 variants could be a possible cause of fetal hydrops.


Assuntos
Heterozigoto , Hidropisia Fetal , Mutação de Sentido Incorreto , Humanos , Feminino , Mutação de Sentido Incorreto/genética , Hidropisia Fetal/genética , Hidropisia Fetal/patologia , Gravidez , Derrame Pleural/genética , Derrame Pleural/patologia , Caderinas/genética , Sequenciamento do Exoma , Polaridade Celular/genética
17.
J Thromb Haemost ; 22(2): 558-564, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37866516

RESUMO

BACKGROUND: Leukocyte adhesion deficiency III (LAD-III) is a rare autosomal recessive syndrome characterized by functional deficiencies of platelets and leukocytes that occurs due to mutations in the FERMT3 gene encoding kindlin-3. Kindlin-3 is a FERM domain-containing adaptor protein that is essential in integrin activation. We have previously demonstrated that the FERM domain of kindlin-3 is structurally compact and plays an important role in supporting integrin activation in a mouse model. The impact of destabilizing the compact FERM domain in kindlin-3 on the development of LAD-III in humans remains uncertain. OBJECTIVES: To use primary cells from a patient with LAD-III to validate the role of the compact FERM domain in kindlin-3 function in platelets and leukocytes. METHODS: The patient is a 4-year-old girl who since infancy has displayed clinical features of LAD-III. Patient platelets and leukocytes were functionally analyzed, and structural analysis of the kindlin-3 variant was conducted. RESULTS: We identified a novel homozygous missense mutation in the FERMT3 (c.412G>A, p.E138K) FERM domain. Substantially reduced levels of kindlin-3 were detected in the proband's platelets and leukocytes. Functional evaluation verified that integrin αIIbß3-mediated platelet activation, spreading, and aggregation and ß2-integrin-mediated neutrophil adhesion and spreading were significantly compromised. Structural analysis revealed that this newly identified E138K substitution in kindlin-3 destabilizes the compacted FERM domain, resulting in poor expression of kindlin-3 in blood cells and subsequent LAD-III. CONCLUSION: We have identified a novel missense mutation and verified the functional significance of the compact kindlin-3 FERM domain in supporting integrin functions in platelets and leukocytes.


Assuntos
Domínios FERM , Síndrome da Aderência Leucocítica Deficitária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas , Animais , Pré-Escolar , Feminino , Humanos , Camundongos , Adesão Celular/genética , Proteínas do Citoesqueleto/metabolismo , Síndrome da Aderência Leucocítica Deficitária/genética , Leucócitos/metabolismo , Mutação , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo
18.
J Med Genet ; 61(3): 224-231, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-37798099

RESUMO

BACKGROUND: Inherited retinal diseases (IRDs) include a range of vision loss conditions caused by variants in different genes. The clinical and genetic heterogeneity make identification of the genetic cause challenging. Here, a cohort of 491 unsolved cases from our cohort of Israeli and Palestinian families with IRDs underwent whole exome sequencing (WES), including detection of CNVs as well as single nucleotide variants (SNVs). METHODS: All participants underwent clinical examinations. Following WES on DNA samples by 3 billion, initial SNV analysis was performed by 3 billion and SNV and CNV analysis by Franklin Genoox. The CNVs indicated by the programme were confirmed by PCR followed by gel electrophoresis. RESULTS: WES of 491 IRD cases revealed the genetic cause of disease in 51% of cases, of which 11% were due wholly or in part to CNVs. In two cases, we clarified previously incorrect or unclear clinical diagnoses. This analysis also identified ESRRB and DNM1 as potential novel genes. CONCLUSION: This analysis is the most extensive one to include CNVs to examine IRD causing genes in the Israeli and Palestinian populations. It has allowed us to identify the causative variant of many patients with IRDs including ones with unclear diagnoses and potential novel genes.


Assuntos
Doenças Retinianas , Humanos , Sequenciamento do Exoma , Doenças Retinianas/genética , Análise de Sequência de DNA/métodos , DNA , Variações do Número de Cópias de DNA/genética
19.
J Med Genet ; 61(3): 239-243, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-37833059

RESUMO

DNA polymerase epsilon (Pol ε), a component of the core replisome, is involved in DNA replication. Although genetic defects of Pol ε have been reported to cause immunodeficiency syndromes, its role in haematopoiesis remains unknown. Here, we identified compound heterozygous variants (p.[Asp1131fs];[Thr1891del]) in POLE, encoding Pol ε catalytic subunit A (POLE1), in siblings with a syndromic form of severe congenital transfusion-dependent anaemia. In contrast to Diamond-Blackfan anaemia, marked reticulocytopenia or marked erythroid hypoplasia was not found. Their bone marrow aspirates during infancy revealed erythroid dysplasia with strongly positive TP53 in immunostaining. Repetitive examinations demonstrated trilineage myelodysplasia within 2 years from birth. They had short stature and facial dysmorphism. HEK293 cell-based expression experiments and analyses of patient-derived induced pluripotent stem cells (iPSCs) disclosed a reduced mRNA level of Asp1131fs-POLE1 and defective nuclear translocation of Thr1891del-POLE1. Analysis of iPSCs showed compensatory mRNA upregulation of the other replisome components and increase of the TP53 protein, both suggesting dysfunction of the replisome. We created Pole-knockout medaka fish and found that heterozygous fishes were viable, but with decreased RBCs. Our observations expand the phenotypic spectrum of the Pol ε defect in humans, additionally providing unique evidence linking Pol ε to haematopoiesis.


Assuntos
DNA Polimerase II , Replicação do DNA , Animais , Humanos , DNA Polimerase II/genética , DNA Polimerase II/metabolismo , Células HEK293 , Replicação do DNA/genética , Proteína Supressora de Tumor p53/genética , RNA Mensageiro
20.
Journal of Clinical Hepatology ; (12): 356-360, 2024.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1007252

RESUMO

This article reports a case with the chief complaint of “hepatosplenomegaly to be investigated” and a confirmed diagnosis of Niemann-Pick disease type B after various tests, and a literature review was conducted to summarize the heterogeneous manifestations of liver involvement in type B Niemann-Pick disease, in order to improve the clinical management of difficult and rare liver diseases.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...