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1.
Brain ; 147(1): 311-324, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-37713627

RESUMO

Highly conserved transport protein particle (TRAPP) complexes regulate subcellular trafficking pathways. Accurate protein trafficking has been increasingly recognized to be critically important for normal development, particularly in the nervous system. Variants in most TRAPP complex subunits have been found to lead to neurodevelopmental disorders with diverse but overlapping phenotypes. We expand on limited prior reports on TRAPPC6B with detailed clinical and neuroradiologic assessments, and studies on mechanisms of disease, and new types of variants. We describe 29 additional patients from 18 independent families with biallelic variants in TRAPPC6B. We identified seven homozygous nonsense (n = 12 patients) and eight canonical splice-site variants (n = 17 patients). In addition, we identified one patient with compound heterozygous splice-site/missense variants with a milder phenotype and one patient with homozygous missense variants. Patients displayed non-progressive microcephaly, global developmental delay/intellectual disability, epilepsy and absent expressive language. Movement disorders including stereotypies, spasticity and dystonia were also observed. Brain imaging revealed reductions in cortex, cerebellum and corpus callosum size with frequent white matter hyperintensity. Volumetric measurements indicated globally diminished volume rather than specific regional losses. We identified a reduced rate of trafficking into the Golgi apparatus and Golgi fragmentation in patient-derived fibroblasts that was rescued by wild-type TRAPPC6B. Molecular studies revealed a weakened interaction between mutant TRAPPC6B (c.454C>T, p.Q152*) and its TRAPP binding partner TRAPPC3. Patient-derived fibroblasts from the TRAPPC6B (c.454C>T, p.Q152*) variant displayed reduced levels of TRAPPC6B as well as other TRAPP II complex-specific members (TRAPPC9 and TRAPPC10). Interestingly, the levels of the TRAPPC6B homologue TRAPPC6A were found to be elevated. Moreover, co-immunoprecipitation experiments showed that TRAPPC6A co-precipitates equally with TRAPP II and TRAPP III, while TRAPPC6B co-precipitates significantly more with TRAPP II, suggesting enrichment of the protein in the TRAPP II complex. This implies that variants in TRAPPC6B may preferentially affect TRAPP II functions compared to TRAPP III functions. Finally, we assessed phenotypes in a Drosophila TRAPPC6B-deficiency model. Neuronal TRAPPC6B knockdown impaired locomotion and led to wing posture defects, supporting a role for TRAPPC6B in neuromotor function. Our findings confirm the association of damaging biallelic TRAPPC6B variants with microcephaly, intellectual disability, language impairments, and epilepsy. A subset of patients also exhibited dystonia and/or spasticity with impaired ambulation. These features overlap with disorders arising from pathogenic variants in other TRAPP subunits, particularly components of the TRAPP II complex. These findings suggest that TRAPPC6B is essential for brain development and function, and TRAPP II complex activity may be particularly relevant for mediating this function.


Assuntos
Distonia , Epilepsia , Deficiência Intelectual , Microcefalia , Transtornos do Neurodesenvolvimento , Animais , Humanos , Microcefalia/genética , Deficiência Intelectual/genética , Proteínas de Transporte Vesicular/genética , Transtornos do Neurodesenvolvimento/genética , Epilepsia/genética
2.
Hum Genet ; 143(3): 311-329, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38459354

RESUMO

Identification of genes associated with nonsyndromic hearing loss is a crucial endeavor given the substantial number of individuals who remain without a diagnosis after even the most advanced genetic testing. PKHD1L1 was established as necessary for the formation of the cochlear hair-cell stereociliary coat and causes hearing loss in mice and zebrafish when mutated. We sought to determine if biallelic variants in PKHD1L1 also cause hearing loss in humans. Exome sequencing was performed on DNA of four families segregating autosomal recessive nonsyndromic sensorineural hearing loss. Compound heterozygous p.[(Gly129Ser)];p.[(Gly1314Val)] and p.[(Gly605Arg)];p[(Leu2818TyrfsTer5)], homozygous missense p.(His2479Gln) and nonsense p.(Arg3381Ter) variants were identified in PKHD1L1 that were predicted to be damaging using in silico pathogenicity prediction methods. In vitro functional analysis of two missense variants was performed using purified recombinant PKHD1L1 protein fragments. We then evaluated protein thermodynamic stability with and without the missense variants found in one of the families and performed a minigene splicing assay for another variant. In silico molecular modeling using AlphaFold2 and protein sequence alignment analysis were carried out to further explore potential variant effects on structure. In vitro functional assessment indicated that both engineered PKHD1L1 p.(Gly129Ser) and p.(Gly1314Val) mutant constructs significantly reduced the folding and structural stabilities of the expressed protein fragments, providing further evidence to support pathogenicity of these variants. Minigene assay of the c.1813G>A p.(Gly605Arg) variant, located at the boundary of exon 17, revealed exon skipping leading to an in-frame deletion of 48 amino acids. In silico molecular modeling exposed key structural features that might suggest PKHD1L1 protein destabilization. Multiple lines of evidence collectively associate PKHD1L1 with nonsyndromic mild-moderate to severe sensorineural hearing loss. PKHD1L1 testing in individuals with mild-moderate hearing loss may identify further affected families.


Assuntos
Surdez , Mutação de Sentido Incorreto , Linhagem , Receptores de Superfície Celular , Estereocílios , Animais , Feminino , Humanos , Masculino , Surdez/genética , Sequenciamento do Exoma , Genes Recessivos , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/patologia , Modelos Moleculares , Receptores de Superfície Celular/genética , Estereocílios/metabolismo , Estereocílios/patologia , Estereocílios/genética
3.
Am J Hum Genet ; 108(6): 1069-1082, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34022130

RESUMO

BCAS3 microtubule-associated cell migration factor (BCAS3) is a large, highly conserved cytoskeletal protein previously proposed to be critical in angiogenesis and implicated in human embryogenesis and tumorigenesis. Here, we established BCAS3 loss-of-function variants as causative for a neurodevelopmental disorder. We report 15 individuals from eight unrelated families with germline bi-allelic loss-of-function variants in BCAS3. All probands share a global developmental delay accompanied by pyramidal tract involvement, microcephaly, short stature, strabismus, dysmorphic facial features, and seizures. The human phenotype is less severe compared with the Bcas3 knockout mouse model and cannot be explained by angiogenic defects alone. Consistent with being loss-of-function alleles, we observed absence of BCAS3 in probands' primary fibroblasts. By comparing the transcriptomic and proteomic data based on probands' fibroblasts with those of the knockout mouse model, we identified similar dysregulated pathways resulting from over-representation analysis, while the dysregulation of some proposed key interactors could not be confirmed. Together with the results from a tissue-specific Drosophila loss-of-function model, we demonstrate a vital role for BCAS3 in neural tissue development.


Assuntos
Mutação com Perda de Função , Perda de Heterozigosidade , Proteínas de Neoplasias/genética , Transtornos do Neurodesenvolvimento/etiologia , Adolescente , Adulto , Animais , Movimento Celular , Criança , Pré-Escolar , Drosophila , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Lactente , Masculino , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/metabolismo , Transtornos do Neurodesenvolvimento/metabolismo , Transtornos do Neurodesenvolvimento/patologia , Linhagem , Proteoma/análise , Adulto Jovem
4.
Mov Disord ; 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38899514

RESUMO

BACKGROUND: Biallelic ZBTB11 variants have previously been associated with an ultrarare subtype of autosomal recessive intellectual developmental disorder (MRT69). OBJECTIVE: The aim was to provide insights into the clinical and genetic characteristics of ZBTB11-related disorders (ZBTB11-RD), with a particular emphasis on progressive complex movement abnormalities. METHODS: Thirteen new and 16 previously reported affected individuals, ranging in age from 2 to 50 years, with biallelic ZBTB11 variants underwent clinical and genetic characterization. RESULTS: All patients exhibited a range of neurodevelopmental phenotypes with varying severity, encompassing ocular and neurological features. Eleven new patients presented with complex abnormal movements, including ataxia, dystonia, myoclonus, stereotypies, and tremor, and 7 new patients exhibited cataracts. Deep brain stimulation was successful in treating 1 patient with generalized progressive dystonia. Our analysis revealed 13 novel variants. CONCLUSIONS: This study provides additional insights into the clinical features and spectrum of ZBTB11-RD, highlighting the progressive nature of movement abnormalities in the background of neurodevelopmental phenotype. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

5.
Clin Genet ; 103(3): 346-351, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36371792

RESUMO

Bi-allelic variants affecting one of the four genes encoding the AP4 subunits are responsible for the "AP4 deficiency syndrome." Core features include hypotonia that progresses to hypertonia and spastic paraplegia, intellectual disability, postnatal microcephaly, epilepsy, and neuroimaging features. Namely, AP4M1 (SPG50) is involved in autosomal recessive spastic paraplegia 50 (MIM#612936). We report on three patients with core features from three unrelated consanguineous families originating from the Middle East. Exome sequencing identified the same homozygous nonsense variant: NM_004722.4(AP4M1):c.1012C>T p.Arg338* (rs146262009). So far, four patients from three other families carrying this homozygous variant have been reported worldwide. We describe their phenotype and compare it to the phenotype of patients with other variants in AP4M1. We construct a shared single-nucleotide polymorphism (SNP) haplotype around AP4M1 in four families and suggest a probable founder effect of Arg338* AP4M1 variant with a common ancestor most likely of Turkish origin.


Assuntos
Epilepsia , Deficiência Intelectual , Paraplegia Espástica Hereditária , Humanos , Deficiência Intelectual/genética , Mutação/genética , Efeito Fundador , Paraplegia/genética , Paraplegia Espástica Hereditária/genética , Epilepsia/genética , Linhagem , Fenótipo
6.
Brain ; 145(9): 3095-3107, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-35718349

RESUMO

The hereditary spastic paraplegias (HSP) are among the most genetically diverse of all Mendelian disorders. They comprise a large group of neurodegenerative diseases that may be divided into 'pure HSP' in forms of the disease primarily entailing progressive lower-limb weakness and spasticity, and 'complex HSP' when these features are accompanied by other neurological (or non-neurological) clinical signs. Here, we identified biallelic variants in the transmembrane protein 63C (TMEM63C) gene, encoding a predicted osmosensitive calcium-permeable cation channel, in individuals with hereditary spastic paraplegias associated with mild intellectual disability in some, but not all cases. Biochemical and microscopy analyses revealed that TMEM63C is an endoplasmic reticulum-localized protein, which is particularly enriched at mitochondria-endoplasmic reticulum contact sites. Functional in cellula studies indicate a role for TMEM63C in regulating both endoplasmic reticulum and mitochondrial morphologies. Together, these findings identify autosomal recessive TMEM63C variants as a cause of pure and complex HSP and add to the growing evidence of a fundamental pathomolecular role of perturbed mitochondrial-endoplasmic reticulum dynamics in motor neurone degenerative diseases.


Assuntos
Canais de Cálcio , Mitocôndrias , Paraplegia Espástica Hereditária , Canais de Cálcio/genética , Retículo Endoplasmático/genética , Humanos , Mitocôndrias/patologia , Mutação , Paraplegia Espástica Hereditária/genética
7.
Am J Hum Genet ; 105(5): 1048-1056, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31668703

RESUMO

NTNG2 encodes netrin-G2, a membrane-anchored protein implicated in the molecular organization of neuronal circuitry and synaptic organization and diversification in vertebrates. In this study, through a combination of exome sequencing and autozygosity mapping, we have identified 16 individuals (from seven unrelated families) with ultra-rare homozygous missense variants in NTNG2; these individuals present with shared features of a neurodevelopmental disorder consisting of global developmental delay, severe to profound intellectual disability, muscle weakness and abnormal tone, autistic features, behavioral abnormalities, and variable dysmorphisms. The variants disrupt highly conserved residues across the protein. Functional experiments, including in silico analysis of the protein structure, in vitro assessment of cell surface expression, and in vitro knockdown, revealed potential mechanisms of pathogenicity of the variants, including loss of protein function and decreased neurite outgrowth. Our data indicate that appropriate expression of NTNG2 plays an important role in neurotypical development.


Assuntos
Proteínas Ligadas por GPI/genética , Mutação de Sentido Incorreto/genética , Netrinas/genética , Transtornos do Neurodesenvolvimento/genética , Adolescente , Adulto , Criança , Pré-Escolar , Exoma/genética , Feminino , Homozigoto , Humanos , Deficiência Intelectual/genética , Masculino , Linhagem , Sequenciamento do Exoma/métodos , Adulto Jovem
8.
Mol Genet Genomics ; 297(5): 1289-1300, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35754085

RESUMO

Genetic ocular diseases are heterogeneous disorders. Recent advances have led to a paradigm shift in the discovery of eye disease-associated genetic variants from linkage and genome-wide association studies to next-generation sequencing-based genome studies. The aim of the current study was to investigate the spectrum of possible vision impairment-related variants in 66 Iranian patients. Whole-exome sequencing (WES) technology followed by bioinformatics analysis, Sanger validation, and co-segregation study were done to find eye disease-causing variants in the patients with vision impairments from Southwest Iran. WES revealed disease-causing variants in 82% of the enrolled cases. WES of understudied cohorts presented an effective strategy for determining pathogenic variants in heterogeneous eye diseases and demonstrated the distribution of causative genetic mutations in Iranian patients. The present data could provide the potential to accelerate genetic screening and a reference for treatment modalities for patients with different types of eye disorders from Southwest Iran.


Assuntos
Exoma , Perfil Genético , Estudo de Associação Genômica Ampla , Humanos , Irã (Geográfico) , Mutação , Linhagem , Transtornos da Visão , Sequenciamento do Exoma
9.
J Med Genet ; 58(7): 495-504, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32719099

RESUMO

BACKGROUND: Adenosine-to-inosine RNA editing is a co-transcriptional/post-transcriptional modification of double-stranded RNA, catalysed by one of two active adenosine deaminases acting on RNA (ADARs), ADAR1 and ADAR2. ADARB1 encodes the enzyme ADAR2 that is highly expressed in the brain and essential to modulate the function of glutamate and serotonin receptors. Impaired ADAR2 editing causes early onset progressive epilepsy and premature death in mice. In humans, ADAR2 dysfunction has been very recently linked to a neurodevelopmental disorder with microcephaly and epilepsy in four unrelated subjects. METHODS: We studied three children from two consanguineous families with severe developmental and epileptic encephalopathy (DEE) through detailed physical and instrumental examinations. Exome sequencing (ES) was used to identify ADARB1 mutations as the underlying genetic cause and in vitro assays with transiently transfected cells were performed to ascertain the impact on ADAR2 enzymatic activity and splicing. RESULTS: All patients showed global developmental delay, intractable early infantile-onset seizures, microcephaly, severe-to-profound intellectual disability, axial hypotonia and progressive appendicular spasticity. ES revealed the novel missense c.1889G>A, p.(Arg630Gln) and deletion c.1245_1247+1 del, p.(Leu415PhefsTer14) variants in ADARB1 (NM_015833.4). The p.(Leu415PhefsTer14) variant leads to incorrect splicing resulting in frameshift with a premature stop codon and loss of enzyme function. In vitro RNA editing assays showed that the p.(Arg630Gln) variant resulted in a severe impairment of ADAR2 enzymatic activity. CONCLUSION: In conclusion, these data support the pathogenic role of biallelic ADARB1 variants as the cause of a distinctive form of DEE, reinforcing the importance of RNA editing in brain function and development.


Assuntos
Adenosina Desaminase/genética , Adenosina Desaminase/metabolismo , Encefalopatias/genética , Epilepsia/genética , Transtornos do Neurodesenvolvimento/genética , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA/genética , Alelos , Encefalopatias/enzimologia , Encefalopatias/metabolismo , Criança , Pré-Escolar , Consanguinidade , Epilepsia/enzimologia , Feminino , Células HEK293 , Humanos , Mutação , Transtornos do Neurodesenvolvimento/enzimologia , Linhagem , Edição de RNA , Proteínas de Ligação a RNA/metabolismo
10.
J Med Genet ; 58(12): 815-831, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33172956

RESUMO

BACKGROUND: Pathogenic variants of GNB5 encoding the ß5 subunit of the guanine nucleotide-binding protein cause IDDCA syndrome, an autosomal recessive neurodevelopmental disorder associated with cognitive disability and cardiac arrhythmia, particularly severe bradycardia. METHODS: We used echocardiography and telemetric ECG recordings to investigate consequences of Gnb5 loss in mouse. RESULTS: We delineated a key role of Gnb5 in heart sinus conduction and showed that Gnb5-inhibitory signalling is essential for parasympathetic control of heart rate (HR) and maintenance of the sympathovagal balance. Gnb5-/- mice were smaller and had a smaller heart than Gnb5+/+ and Gnb5+/- , but exhibited better cardiac function. Lower autonomic nervous system modulation through diminished parasympathetic control and greater sympathetic regulation resulted in a higher baseline HR in Gnb5-/- mice. In contrast, Gnb5-/- mice exhibited profound bradycardia on treatment with carbachol, while sympathetic modulation of the cardiac stimulation was not altered. Concordantly, transcriptome study pinpointed altered expression of genes involved in cardiac muscle contractility in atria and ventricles of knocked-out mice. Homozygous Gnb5 loss resulted in significantly higher frequencies of sinus arrhythmias. Moreover, we described 13 affected individuals, increasing the IDDCA cohort to 44 patients. CONCLUSIONS: Our data demonstrate that loss of negative regulation of the inhibitory G-protein signalling causes HR perturbations in Gnb5-/- mice, an effect mainly driven by impaired parasympathetic activity. We anticipate that unravelling the mechanism of Gnb5 signalling in the autonomic control of the heart will pave the way for future drug screening.


Assuntos
Arritmias Cardíacas/genética , Deficiências do Desenvolvimento/genética , Subunidades beta da Proteína de Ligação ao GTP/genética , Coração/fisiopatologia , Mutação , Transdução de Sinais/genética , Adolescente , Animais , Arritmias Cardíacas/fisiopatologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Perfilação da Expressão Gênica/métodos , Frequência Cardíaca/genética , Frequência Cardíaca/fisiologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linhagem , Síndrome , Sequenciamento do Exoma/métodos , Adulto Jovem
11.
Hum Genet ; 140(6): 915-931, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33496845

RESUMO

Deafness, the most frequent sensory deficit in humans, is extremely heterogeneous with hundreds of genes involved. Clinical and genetic analyses of an extended consanguineous family with pre-lingual, moderate-to-profound autosomal recessive sensorineural hearing loss, allowed us to identify CLRN2, encoding a tetraspan protein, as a new deafness gene. Homozygosity mapping followed by exome sequencing identified a 14.96 Mb locus on chromosome 4p15.32p15.1 containing a likely pathogenic missense variant in CLRN2 (c.494C > A, NM_001079827.2) segregating with the disease. Using in vitro RNA splicing analysis, we show that the CLRN2 c.494C > A variant leads to two events: (1) the substitution of a highly conserved threonine (uncharged amino acid) to lysine (charged amino acid) at position 165, p.(Thr165Lys), and (2) aberrant splicing, with the retention of intron 2 resulting in a stop codon after 26 additional amino acids, p.(Gly146Lysfs*26). Expression studies and phenotyping of newly produced zebrafish and mouse models deficient for clarin 2 further confirm that clarin 2, expressed in the inner ear hair cells, is essential for normal organization and maintenance of the auditory hair bundles, and for hearing function. Together, our findings identify CLRN2 as a new deafness gene, which will impact future diagnosis and treatment for deaf patients.


Assuntos
Substituição de Aminoácidos , Cromossomos Humanos Par 4/química , Células Ciliadas Auditivas Internas/metabolismo , Perda Auditiva Neurossensorial/genética , Proteínas de Membrana/genética , Mutação Puntual , Tetraspaninas/genética , Adulto , Alelos , Animais , Sequência de Bases , Mapeamento Cromossômico , Consanguinidade , Feminino , Expressão Gênica , Genes Recessivos , Células Ciliadas Auditivas Internas/patologia , Perda Auditiva Neurossensorial/metabolismo , Perda Auditiva Neurossensorial/patologia , Humanos , Masculino , Proteínas de Membrana/deficiência , Camundongos , Linhagem , Tetraspaninas/deficiência , Sequenciamento do Exoma , Peixe-Zebra
12.
Genet Med ; 23(4): 787-792, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33288880

RESUMO

PURPOSE: Variants in genes encoding sarcomeric proteins are the most common cause of inherited cardiomyopathies. However, the underlying genetic cause remains unknown in many cases. We used exome sequencing to reveal the genetic etiology in patients with recessive familial cardiomyopathy. METHODS: Exome sequencing was carried out in three consanguineous families. Functional assessment of the variants was performed. RESULTS: Affected individuals presented with hypertrophic or dilated cardiomyopathy of variable severity from infantile- to early adulthood-onset and sudden cardiac death. We identified a homozygous missense substitution (c.170C>A, p.[Ala57Asp]), a homozygous translation stop codon variant (c.106G>T, p.[Glu36Ter]), and a presumable homozygous essential splice acceptor variant (c.482-1G>A, predicted to result in skipping of exon 5). Morpholino knockdown of the MYL3 orthologue in zebrafish, cmlc1, resulted in compromised cardiac function, which could not be rescued by reintroduction of MYL3 carrying either the nonsense c.106G>T or the missense c.170C>A variants. Minigene assay of the c.482-1G>A variant indicated a splicing defect likely resulting in disruption of the EF-hand Ca2+ binding domains. CONCLUSIONS: Our data demonstrate that homozygous MYL3 loss-of-function variants can cause of recessive cardiomyopathy and occurrence of sudden cardiac death, most likely due to impaired or loss of myosin essential light chain function.


Assuntos
Cardiomiopatias , Cardiomiopatia Dilatada , Cadeias Leves de Miosina/genética , Animais , Cardiomiopatias/genética , Cardiomiopatia Dilatada/genética , Consanguinidade , Morte Súbita Cardíaca/etiologia , Humanos , Linhagem , Peixe-Zebra/genética
13.
Am J Hum Genet ; 100(3): 537-545, 2017 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-28190459

RESUMO

Congenital muscular dystrophies display a wide phenotypic and genetic heterogeneity. The combination of clinical, biochemical, and molecular genetic findings must be considered to obtain the precise diagnosis and provide appropriate genetic counselling. Here we report five individuals from four families presenting with variable clinical features including muscular dystrophy with a reduction in dystroglycan glycosylation, short stature, intellectual disability, and cataracts, overlapping both the dystroglycanopathies and Marinesco-Sjögren syndrome. Whole-exome sequencing revealed homozygous missense and compound heterozygous mutations in INPP5K in the affected members of each family. INPP5K encodes the inositol polyphosphate-5-phosphatase K, also known as SKIP (skeletal muscle and kidney enriched inositol phosphatase), which is highly expressed in the brain and muscle. INPP5K localizes to both the endoplasmic reticulum and to actin ruffles in the cytoplasm. It has been shown to regulate myoblast differentiation and has also been implicated in protein processing through its interaction with the ER chaperone HSPA5/BiP. We show that morpholino-mediated inpp5k loss of function in the zebrafish results in shortened body axis, microphthalmia with disorganized lens, microcephaly, reduced touch-evoked motility, and highly disorganized myofibers. Altogether these data demonstrate that mutations in INPP5K cause a congenital muscular dystrophy syndrome with short stature, cataracts, and intellectual disability.


Assuntos
Distrofia Muscular do Cíngulo dos Membros/genética , Monoéster Fosfórico Hidrolases/genética , Degenerações Espinocerebelares/genética , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Encéfalo/metabolismo , Criança , Modelos Animais de Doenças , Distroglicanas/metabolismo , Retículo Endoplasmático/metabolismo , Chaperona BiP do Retículo Endoplasmático , Feminino , Estudo de Associação Genômica Ampla , Glicosilação , Transtornos do Crescimento/genética , Humanos , Deficiência Intelectual/genética , Masculino , Microcefalia/genética , Músculo Esquelético/metabolismo , Mutação , Linhagem , Adulto Jovem , Peixe-Zebra/genética
14.
Hemoglobin ; 44(4): 225-230, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32672086

RESUMO

ß-Thalassemia (ß-thal) is one of the most frequent genetic disorder in Iran with great mutational diversity. In this study, we describe two novel and five rare mutations in the non coding regions of the ß-globin gene; these mutations were identified in the non coding regions of the ß-globin gene (HBB) in the heterozygous state. Three alterations were detected in the promoter region, including -9 (C>G) [HBB: c.59C>G (novel mutation)], -54 (G>A) (HBB: c.-104G>A) and -57 (A>T) (HBB: c.-107A>T), three changes in the 5' untranslated region (5'UTR) including +11 (C>G) [HBB: c.-40C>G (novel mutation)], +41 (A>T) (HBB: c.-10A>T) and +43 (C>G) (HBB: c.-8C>G) and one mutation in the 3'UTR 62 (A>G) (HBB: c.*62A>G). Five mutations including -54, -57, +41, +11 and +43 were predicted to be deleterious in all except one in silico prediction tool, and the remaining two mutations were found to be most likely polymorphisms. In conclusion, two novel mutations were reported for the first time worldwide and five rare changes have not been reported previously in any other part of Iran. In the absence of further data, it is not possible to consider them as mutations that determine an ascertained healthy carrier state.


Assuntos
Hemoglobinopatias/epidemiologia , Hemoglobinopatias/genética , Mutação , Regiões não Traduzidas , Globinas beta/genética , Alelos , Análise Mutacional de DNA , Feminino , Frequência do Gene , Genótipo , Hemoglobinopatias/diagnóstico , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Vigilância da População , Análise de Sequência de DNA
15.
J Pediatr Hematol Oncol ; 40(3): 192-195, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29420372

RESUMO

BACKGROUND: Any mutation in the Krüppel-like factor 1 (KLF1) gene may interfere with its proper related function in the erythropoiesis process and lead to alterations in proper activation of its downstream protein through globin switching, which results in an increase in fetal hemoglobin (HbF). This study aimed to investigate whether KLF1 mutation can associate with high level of HbF in individuals with increased fetal hemoglobin referred for screening of hemoglobinopathies in south of Iran. MATERIALS AND METHODS: The human KLF1 gene was amplified via the polymerase chain reaction procedure, and sequencing was used to determine any mutation in these patients. Moreover, XmnI polymorphisms in the position of -158 of γ-globin gene promoter were analyzed in all patients by polymerase chain reaction restriction fragment length polymorphism. RESULT: Analysis of sequencing revealed a missense mutation in the KLF1 gene, p.Ser102Pro (c.304T>C), which was detectable in 10 of 23 cases with elevated HbF level. This mutation was only detected in individuals who had a HbF level between 3.1% and 25.6%. Statistical analysis showed that the frequency of C allele is significantly correlated with a high level of HbF (P<0.05). The allele frequency of positive result of XmnI polymorphism in individuals with increased HbF level was also significant, which showed an association with increased HbF level (P<0.05). CONCLUSIONS: To the best of our knowledge, this is the first report of p.Ser102Pro (c.304T>C) in the KLF1 gene in ß-thalassemia patients with increased level of fetal hemoglobin. According to statistical results of p.Ser102Pro mutation and XmnI polymorphism, it has been strongly suggested that both polymorphisms have an association with increased HbF samples. These nucleotide changes alone may not be the only elements raising the level of HbF, and other regulatory and modifying factors also play a role in HbF production.


Assuntos
Hemoglobina Fetal , Fatores de Transcrição Kruppel-Like/genética , Talassemia beta/genética , Análise Mutacional de DNA , Humanos , Irã (Geográfico) , Mutação
16.
Neurol Sci ; 39(11): 1917-1925, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30128655

RESUMO

Biallelic mutations of the alsin Rho guanine nucleotide exchange factor (ALS2) gene cause a group of overlapping autosomal recessive neurodegenerative disorders including infantile-onset ascending hereditary spastic paralysis (IAHSP), juvenile primary lateral sclerosis (JPLS), and juvenile amyotrophic lateral sclerosis (JALS/ALS2), caused by retrograde degeneration of the upper motor neurons of the pyramidal tracts. Here, we describe 11 individuals with IAHSP, aged 2-48 years, with IAHSP from three unrelated consanguineous Iranian families carrying the homozygous c.1640+1G>A founder mutation in ALS2. Three affected siblings from one family exhibit generalized dystonia which has not been previously described in families with IAHSP and has only been reported in three unrelated consanguineous families with JALS/ALS2. We report the oldest individuals with IAHSP to date and provide evidence that these patients survive well into their late 40s with preserved cognition and normal eye movements. Our study delineates the phenotypic spectrum of IAHSP and ALS2-related disorders and provides valuable insights into the natural disease course.


Assuntos
Saúde da Família , Fatores de Troca do Nucleotídeo Guanina/genética , Mutação/genética , Paraplegia Espástica Hereditária/genética , Paraplegia Espástica Hereditária/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Biochem Genet ; 56(5): 506-521, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29627922

RESUMO

Alpha thalassemia is the most prevalent monogenic gene disorder in the world, especially in Mediterranean countries. In the current hematological phenotype of patients with different genotypes, the effects of missense mutations on the protein function and also stability were evaluated in a large cohort study. A total of 1,560 subjects were enrolled in the study and divided into two groups: 259 normal subjects; and 1301 alpha-thalassemia carriers. Genomic DNA was extracted and analyzed using ARMS PCR, Multiplex Gap, and direct sequencing. The effects of single nucleotide change on the protein function and stability were predicted by freely available databases of human polymorphisms. Sixty-three different genotypes were seen in the patients. The more prevalent was heterozygote form of -α3.7 (41.4%) followed by -α3.7 homozygote (11.6%) and -MED (3.8%). The significant differences were seen in mean hemoglobin level [F = 20.5, p < 0.001] between the Alpha-globin genotypes, when adjusted for gender. Moreover, 28 different mutations were found in our study. A significant relationship was seen between ethnicity and the alpha-globin mutation frequency χ2 (df;8) = 38.36, p < 0.0001). Different genotypes could display as different phenotypes. The mutation frequency distributions in our region are different from those of other parts of Iran. Significant differences are seen in the spectrum of mutation frequency among various ethnicities. Finally, some missense mutations might not have considerable effect on the proteins, and they could be neutral mutations.


Assuntos
Mutação de Sentido Incorreto , População Branca/genética , alfa-Globinas/genética , Talassemia alfa/genética , Adulto , Estudos de Coortes , Feminino , Humanos , Irã (Geográfico)/etnologia , Masculino , Estabilidade Proteica , Análise de Sequência de DNA , População Branca/etnologia , Adulto Jovem , alfa-Globinas/química , alfa-Globinas/metabolismo
18.
BMC Complement Altern Med ; 16(1): 386, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27716154

RESUMO

BACKGROUND: Wound healing is often impaired in diabetic animals and humans. Matrix metalloproteases act as pro-inflammatory agents in physiological wound healing pathways by stimulating cytokines including the interleukins, IL6, IL1A and IL1B, and the tumor necrosis factor and transforming growth factor beta1. Botanicals are traditionally used to assist healing of different types of wounds, because they produce fewer side effects. Our specific aim here was to develop a plant-based recipe supporting effective wound healing in diabetic animals. METHODS: Plant materials from Adiantum capillus-veneris, Commiphora molmol, Aloe Vera, and henna were collected for this study, and oven-dried at 60 °C. The dried leaves and resins were then crumbled into a powder and mixed in equal parts with Vaseline as a preservative. This mixture was used as an ointment on wounds induced in 60 diabetic and non-diabetic rats that were divided into 6 subgroups receiving agent or control treatments. Necrotic tissue surrounding the wound was periodically removed during wound healing. RNA was extracted from the healing region of the wound at days 7, 14 and 21 for cDNA synthesis to monitor changes in Tgfb1, Mmp3, Mmp9, Il6 and Tnf α expression using real-time PCR. RESULTS: The expression of the Mmp3, the Tnf α, and the Tgfb1 genes from wound tissue were significantly different (p < 0.05) between diabetic and non-diabetic (control) rats treated with the herbal mixture after 14 and 21 days. There was no significant difference (p > 0.05) of the Mmp9 gene expression in diabetic and non-diabetic rats treated only with Vaseline after 7, 14, and 21 days. But, the expression of the Mmp9 gene decreased significantly (p < 0.05) in diabetic rats after 14 days in comparison to non-diabetic rats, when the herbal mixture was added to Vaseline. CONCLUSIONS: Our study presents an herbal treatment that alters the gene expression signature at wounds induced in the rat model for type I diabetes in a manner consistent with accelerated healing, and demonstrates that this herbal treatment might be effective to treat wounds in diabetic patients.


Assuntos
Adiantum/química , Aloe/química , Diabetes Mellitus Experimental/metabolismo , Lawsonia (Planta)/química , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Expressão Gênica/efeitos dos fármacos , Masculino , Metaloproteinases da Matriz/metabolismo , Extratos Vegetais/química , Ratos , Ratos Wistar
19.
Mol Genet Genomic Med ; 12(1): e2294, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37818795

RESUMO

BACKGROUND: Hyperphenylalaninemia (HPA) is a metabolic disorder classified into phenylalanine-4-hydroxylase (PAH) and non-PAH deficiency. The latter is produced by mutations in genes involved in the tetrahydrobiopterin (BH4) biosynthesis pathway and DNAJC12 pathogenetic variants. The BH4 metabolism, including de novo biosynthesis involved genes (i.e., guanosine 5'-triphosphate cyclohydrolase I (GTPCH/GCH1), sepiapterin reductase (SR/SPR), 6-pyruvoyl-tetrahydropterin synthase (PTPS/PTS)), and two genes that play roles in cofactor regeneration pathway (i.e., dihydropteridine reductase (DHPR/QDPR) and pterin-4α-carbinolamine dehydratase (PCD/PCBD1)). The subsequent systemic hyperphenylalaninemia and monoamine neurotransmitter deficiency lead to neurological consequences. The high rate of consanguineous marriages in Iran substantially increases the incidence of BH4 deficiency. METHODS: We utilized the Sanger sequencing technique in this study to investigate 14 Iranian patients with non-PAH deficiency. All affected subjects in this study had HPA and no mutation was detected in their PAH gene. RESULTS: We successfully identified six mutant alleles in BH4-deficiency-associated genes, including three novel mutations: one in QDPR, one in PTS, and one in the PCBD1 gene, thus giving a definite diagnosis to these patients. CONCLUSION: In this light, appropriate patient management may follow. The clinical effect of reported variants is essential for genetic counseling and prenatal diagnosis in the patients' families and significant for the improvement of precision medicine.


Assuntos
Fenilalanina Hidroxilase , Fenilcetonúrias , Gravidez , Feminino , Humanos , Irã (Geográfico) , Fenilcetonúrias/genética , Fenilcetonúrias/epidemiologia , Biopterinas , Di-Hidropteridina Redutase/genética , Fenilalanina Hidroxilase/genética
20.
Heliyon ; 10(7): e28528, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38590857

RESUMO

Background: Severe acute respiratory syndrome coronavirus 2 was first reported in December 2019 and it has spread globally ever since. The HLA system is crucial in directing anti-viral immunity and recent studies are investigating the possible involvement of the HLA genes on the severity of immune inflammation in different phases of COVID-19. Methods: In this cross-sectional study, peripheral blood-extracted genomic DNAs of 109 COVID-19 patients and 70 healthy controls were genotyped for different alleles of HLA-A, HLA-B, and HLA-DRB1 loci using sequence-specific primer PCR method. Results: The results indicated that frequencies of HLA-DRB1*11:01 and HLA-DRB1*04:03 were significantly higher in severe patients rather than moderates (p: <0.001 and 0.004, respectively). Also, it was observed that HLA-DRB1*04:01 was more frequent in moderate patients and healthy controls (p:0.002). In addition, HLA-B*07:35, and HLA-DRB1*07:01 showed higher frequencies in patients compared with controls (p: 0.031 and 0.003 respectively). Inversely, due to the higher frequencies of HLA-B*51:01 (p:0.027), HLA-DRB1*11:05 (p:0.003), HLA-DRB1*13:05 (p:0.022), and HLA-DRB1*14:01 (p:0.006) in healthy individuals rather than patients, they may be associated with COVID-19 resistance. Conclusion: The results show that, based on the population differences, the type of alleles related to the severity of COVID-19 is different, which should be clarified by designing large-scale studies in order to develop HLA-based treatments and vaccines.

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