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1.
Genes (Basel) ; 14(9)2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37761885

RESUMO

In 1990, Gorlin et al. described four types of craniofacial duplications: (1) single mouth with duplication of the maxillary arch; (2) supernumerary mouth laterally placed with rudimentary segments; (3) single mouth with replication of the mandibular segments; and (4) true facial duplication, namely diprosopus. We describe a newborn born with wide-spaced eyes, a very broad nose, and two separate mouths. Workup revealed the absence of the corpus callosum and the presence of a brain midline lipoma, wide sutures, and a Chiari I malformation with cerebellar herniation. We conducted a systematic review of the literature and compared all the cases described as diprosopus. In 96% of these, the central nervous system is affected, with anencephaly being the most commonly associated abnormality. Other associated anomalies include cardiac malformations (86%), cleft palate (63%), diaphragmatic hernia (13%), and disorder of sex development (DSD) (13%). Although the facial features are those that first strike the eye, the almost obligate presence of cerebral malformations suggests a disruptive event in the cephalic pole of the forming embryo. No major monogenic contribution has been recognized today for this type of malformation.


Assuntos
Fissura Palatina , Recém-Nascido , Humanos , Face , Encéfalo/diagnóstico por imagem , Sistema Nervoso Central
2.
Bone ; 175: 116838, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37454964

RESUMO

Diastrophic dysplasia (DTD) is a recessive chondrodysplasia caused by pathogenic variants in the SLC26A2 gene encoding for a cell membrane sulfate/chloride antiporter crucial for sulfate uptake and glycosaminoglycan (GAG) sulfation. Research on a DTD animal model has suggested possible pharmacological treatment approaches. In view of future clinical trials, the identification of non-invasive biomarkers is crucial to assess the efficacy of treatments. Urinary GAG composition has been analyzed in several metabolic disorders including mucopolysaccharidoses. Moreover, the N-terminal fragment of collagen X, known as collagen X marker (CXM), is considered a real-time marker of endochondral ossification and growth velocity and was studied in individuals with achondroplasia and osteogenesis imperfecta. In this work, urinary GAG sulfation and blood CXM levels were investigated as potential biomarkers for individuals affected by DTD. Chondroitin sulfate disaccharide analysis was performed on GAGs isolated from urine by HPLC after GAG digestion with chondroitinase ABC and ACII, while CXM was assessed in dried blood spots. Results from DTD patients were compared with an age-matched control population. Undersulfation of urinary GAGs was observed in DTD patients with some relationship to the clinical severity and underlying SLC26A2 variants. Lower than normal CXM levels were observed in most patients, even if the marker did not show a clear pattern in our small patient cohort because CXM values are highly dependent on age, gender and growth velocity. In summary, both non-invasive biomarkers are promising assays targeting various aspects of the disorder including overall metabolism of sulfated GAGs and endochondral ossification.


Assuntos
Acondroplasia , Proteínas de Transporte de Ânions , Animais , Proteínas de Transporte de Ânions/genética , Transportadores de Sulfato , Glicosaminoglicanos , Biomarcadores , Colágeno/metabolismo , Sulfatos/metabolismo
3.
Clin Genet ; 104(2): 230-237, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37038048

RESUMO

Spondylocostal dysostosis (SCD), a condition characterized by multiple segmentation defects of the vertebrae and rib malformations, is caused by bi-allelic variants in one of the genes involved in the Notch signaling pathway that tunes the "segmentation clock" of somitogenesis: DLL3, HES7, LFNG, MESP2, RIPPLY2, and TBX6. To date, seven individuals with LFNG variants have been reported in the literature. In this study we describe two newborns and one fetus with SCD, who were found by trio-based exome sequencing (trio-ES) to carry homozygous (c.822-5C>T) or compound heterozygous (c.[863dup];[1063G>A]) and (c.[521G>T];[890T>G]) variants in LFNG. Notably, the c.822-5C>T change, affecting the polypyrimidine tract of intron 5, is the first non-coding variant reported in LFNG. This study further refines the clinical and molecular features of spondylocostal dysostosis 3 and adds to the numerous investigations supporting the usefulness of trio-ES approach in prenatal and neonatal settings.


Assuntos
Anormalidades Múltiplas , Hérnia Diafragmática , Humanos , Recém-Nascido , Coluna Vertebral/anormalidades , Anormalidades Múltiplas/genética , Hérnia Diafragmática/genética , Alelos , Proteínas com Domínio T/genética , Proteínas de Membrana/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética
5.
Hum Mol Genet ; 31(24): 4131-4142, 2022 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-35861666

RESUMO

KBG syndrome (KBGS) is characterized by distinctive facial gestalt, short stature and variable clinical findings. With ageing, some features become more recognizable, allowing a differential diagnosis. We aimed to better characterize natural history of KBGS. In the context of a European collaborative study, we collected the largest cohort of KBGS patients (49). A combined array- based Comparative Genomic Hybridization and next generation sequencing (NGS) approach investigated both genomic Copy Number Variants and SNVs. Intellectual disability (ID) (82%) ranged from mild to moderate with severe ID identified in two patients. Epilepsy was present in 26.5%. Short stature was consistent over time, while occipitofrontal circumference (median value: -0.88 SD at birth) normalized over years. Cerebral anomalies, were identified in 56% of patients and thus represented the second most relevant clinical feature reinforcing clinical suspicion in the paediatric age when short stature and vertebral/dental anomalies are vague. Macrodontia, oligodontia and dental agenesis (53%) were almost as frequent as skeletal anomalies, such as brachydactyly, short fifth finger, fifth finger clinodactyly, pectus excavatum/carinatum, delayed bone age. In 28.5% of individuals, prenatal ultrasound anomalies were reported. Except for three splicing variants, leading to a premature termination, variants were almost all frameshift. Our results, broadening the spectrum of KBGS phenotype progression, provide useful tools to facilitate differential diagnosis and improve clinical management. We suggest to consider a wider range of dental anomalies before excluding diagnosis and to perform a careful odontoiatric/ear-nose-throat (ENT) evaluation in order to look for even submucosal palate cleft given the high percentage of palate abnormalities. NGS approaches, following evidence of antenatal ultrasound anomalies, should include ANKRD11.


Assuntos
Anormalidades Múltiplas , Doenças do Desenvolvimento Ósseo , Nanismo , Deficiência Intelectual , Anormalidades Dentárias , Gravidez , Feminino , Humanos , Fácies , Anormalidades Dentárias/genética , Doenças do Desenvolvimento Ósseo/genética , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/diagnóstico , Deficiência Intelectual/genética , Deficiência Intelectual/diagnóstico , Hibridização Genômica Comparativa , Proteínas Repressoras/genética , Fenótipo , Nanismo/genética , População Europeia
6.
Am J Hum Genet ; 109(3): 457-470, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-35120630

RESUMO

We used a machine learning approach to analyze the within-gene distribution of missense variants observed in hereditary conditions and cancer. When applied to 840 genes from the ClinVar database, this approach detected a significant non-random distribution of pathogenic and benign variants in 387 (46%) and 172 (20%) genes, respectively, revealing that variant clustering is widespread across the human exome. This clustering likely occurs as a consequence of mechanisms shaping pathogenicity at the protein level, as illustrated by the overlap of some clusters with known functional domains. We then took advantage of these findings to develop a pathogenicity predictor, MutScore, that integrates qualitative features of DNA substitutions with the new additional information derived from this positional clustering. Using a random forest approach, MutScore was able to identify pathogenic missense mutations with very high accuracy, outperforming existing predictive tools, especially for variants associated with autosomal-dominant disease and cancer. Thus, the within-gene clustering of pathogenic and benign DNA changes is an important and previously underappreciated feature of the human exome, which can be harnessed to improve the prediction of pathogenicity and disambiguation of DNA variants of uncertain significance.


Assuntos
Genoma Humano , Mutação de Sentido Incorreto , Análise por Conglomerados , Exoma/genética , Genoma Humano/genética , Humanos , Mutação de Sentido Incorreto/genética , Virulência
7.
Genes (Basel) ; 13(2)2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35205306

RESUMO

Osteocraniostenosis (OCS, OMIM #602361) is a severe, usually lethal condition characterized by gracile bones with thin diaphyses, a cloverleaf-shaped skull and splenic hypo/aplasia. The condition is caused by heterozygous mutations in the FAM111A gene and is allelic to the non-lethal, dominant disorder Kenny-Caffey syndrome (KCS, OMIM #127000). Here we report two new cases of OCS, including one with a detailed pathological examination. We review the main diagnostic signs of OCS both before and after birth based on our observations and on the literature. We then review the current knowledge on the mutational spectrum of FAM111A associated with either OCS or KCS, including three novel variants, both from one of the OCS fetuses described here, and from further cases diagnosed at our centers. This report refines the previous knowledge on OCS and expands the mutational spectrum that results in either OCS or KCS.


Assuntos
Doenças do Desenvolvimento Ósseo , Hiperostose Cortical Congênita , Doenças do Desenvolvimento Ósseo/diagnóstico , Doenças do Desenvolvimento Ósseo/genética , Doenças do Desenvolvimento Ósseo/patologia , Anormalidades Craniofaciais , Feminino , Feto/diagnóstico por imagem , Feto/patologia , Humanos , Hiperostose Cortical Congênita/diagnóstico , Hiperostose Cortical Congênita/genética , Hiperostose Cortical Congênita/patologia , Recém-Nascido , Gravidez , Ultrassonografia Pré-Natal
8.
Am J Med Genet A ; 188(1): 319-325, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34580982

RESUMO

Cranio-lenticulo-sutural dysplasia (CLSD; MIM 607812) is a rare or underdiagnosed condition, as only two families have been reported. The original family (Boyadjiev et al., Human Genetics, 2003, 113, 1-9 and Boyadjiev et al., Nature Genetics, 2006, 38, 1192-1197) showed recessive inheritance of the condition with a biallelic SEC23A missense variant in affected individuals. In contrast, another child with sporadic CLSD had a monoallelic SEC23A variant inherited from the reportedly unaffected father (Boyadjiev et al., Clinical Genetics, 2011, 80, 169-176), raising questions on possible digenism. Here, we report a 2-month-old boy seen because of large fontanels with wide cranial sutures, a large forehead, hypertelorism, a thin nose, a high arched palate, and micrognathia. His mother was clinically unremarkable, while his father had a history of large fontanels in infancy who had closed only around age 10 years; he also had a large forehead, hypertelorism, a thin, beaked nose and was operated for bilateral glaucoma with exfoliation of the lens capsule. Trio genome sequencing and familial segregation revealed a monoallelic c.1795G > A transition in SEC23A that was de novo in the father and transmitted to the proband. The variant predicts a nonconservative substitution (p.E599K) in an ultra-conserved residue that is seen in 3D models of yeast SEC23 to be involved in direct binding between SEC23 and SAR1 subunits of the coat protein complex II coat. This observation confirms the link between SEC23A variants and CLSD but suggests that in addition to the recessive inheritance described in the original family, SEC23A variants may result in dominant inheritance of CLSD, possibly by a dominant-negative disruptive effect on the SEC23 multimer.


Assuntos
Mutação de Sentido Incorreto , Proteínas de Transporte Vesicular , Sequência de Bases , Criança , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto/genética , Proteínas de Transporte Vesicular/genética
9.
Front Genet ; 12: 529236, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220921

RESUMO

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Despite appropriate therapy, 20-40% of affected-patients evolve toward end-stage kidney disease (ESKD). Mesangial IgA deposits are the hallmark of IgAN, and complement deposition (C3) seems to differentiate latent IgA mesangial deposits from active IgAN. Atypical hemolytic uremic syndrome (aHUS), another disease in which complement plays an important role, is caused by inherited or acquired deregulation of the alternative pathway (AP) of complement. A subgroup of IgAN shows thrombotic microangiopathy (TMA) lesions in kidney biopsies, the histological characteristic of aHUS. Genetic variants of complement Factor H (CFH), known to be present in aHUS, have been associated with rapidly progressive forms of IgAN and a clinical pattern of aHUS. Genome-wide association studies (GWAS) have confirmed that the 1q32 region, encoding for CFH and its related proteins, is an IgAN susceptibility locus. A 30 year-old man was admitted for seizures and malignant hypertension. The kidney biopsy showed IgAN associated with features of TMA. Despite five plasma exchanges, the patient remained dialysis-dependent, and ESKD was diagnosed. Functional and genetic complement analysis were performed. A monoallelic protein-truncating, likely loss-of-function variant was identified in the CFHR5 gene. Eculizumab is the treatment of aHUS. As it has been successfully used in a few cases of rapidly progressive IgAN, it was decided to administer eculizumab over a period of 12 months in addition to the usual immunosuppression for renal transplantation. After a follow-up of 3 years, there was no clinical disease recurrence. Systematic biologic and genetic screening of complement in individuals with IgAN might be useful to better delineate the role of the AP of complement in renal disease progression, and this may have therapeutic implications.

10.
Am J Med Genet A ; 185(12): 3831-3837, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34296525

RESUMO

Polydactyly is a hallmark of GLI3 pathogenic variants, with Greig cephalopolysyndactyly syndrome and Pallister-Hall syndrome being the two main associated clinical presentations. Homozygous GLI3 variants are rare instances in the literature, and mendelian dominance is the accepted framework for GLI3-related diseases. Herein, we report three unrelated probands, presenting with polydactyly, and homozygous variants in the GLI3 gene. First, a 10-year-old girl, whose parents were first-degree cousins, presented with bilateral postaxial polydactyly of the hands, developmental delay and multiple malformations. Second, a male newborn, whose parents were first-degree cousins, presented with isolated bilateral postaxial polysyndactyly of the hands and the feet. Third, an adult male, whose parents were first-degree cousins, had bilateral mesoaxial polydactyly of the hands, with severe intellectual disability and multiple malformations. All three probands carried homozygous GLI3 variants. Strikingly, the parents also carried the child's variant, in the heterozygous state, without any clinical sign of GLI3 disease. Given the clinical presentation of our patients, the rarity and predicted high pathogenicity of the variants observed, and the absence of other pathogenic variants, we suggest that these GLI3 homozygous variants are causal. Moreover, the parents were heterozygous for the observed variants, but were clinically unremarkable, suggesting that these variants are hypomorphic alleles.


Assuntos
Predisposição Genética para Doença , Proteínas do Tecido Nervoso/genética , Polidactilia/genética , Proteína Gli3 com Dedos de Zinco/genética , Adulto , Criança , Feminino , Heterozigoto , Homozigoto , Humanos , Recém-Nascido , Masculino , Linhagem , Polidactilia/patologia
11.
Genes (Basel) ; 12(5)2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-34066437

RESUMO

The identification of neurological disorders by next-generation sequencing (NGS)-based gene panels has helped clinicians understand the underlying physiopathology, resulting in personalized treatment for some rare diseases. While the phenotype of distinct neurogenetic disorders is generally well-known in childhood, in adulthood, the phenotype can be unspecific and make the standard diagnostic approach more complex. Here we present three unrelated adults with various neurological manifestations who were successfully diagnosed using NGS, allowing for the initiation of potentially life-changing treatments. A 63-year-old woman with progressive cognitive decline, pyramidal signs, and bilateral cataract was treated by chenodeoxycholic acid following the diagnosis of cerebrotendinous xanthomatosis due to a homozygous variant in CYP27A1. A 32-year-old man with adult-onset spastic paraplegia, in whom a variant in ABCD1 confirmed an X-linked adrenoleukodystrophy, was treated with corticoids for adrenal insufficiency. The third patient, a 28-year-old woman with early-onset developmental delay, epilepsy, and movement disorders was treated with a ketogenic diet following the identification of a variant in SLC2A1, confirming a glucose transporter type 1 deficiency syndrome. This case study illustrates the challenges in the timely diagnosis of medically actionable neurogenetic conditions, but also the considerable potential for improving patient health through modern sequencing technologies.


Assuntos
Adrenoleucodistrofia/genética , Erros Inatos do Metabolismo dos Carboidratos/genética , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Proteínas de Transporte de Monossacarídeos/deficiência , Xantomatose Cerebrotendinosa/genética , Membro 1 da Subfamília D de Transportadores de Cassetes de Ligação de ATP/genética , Adrenoleucodistrofia/diagnóstico , Adulto , Erros Inatos do Metabolismo dos Carboidratos/diagnóstico , Colestanotriol 26-Mono-Oxigenase/genética , Feminino , Transportador de Glucose Tipo 1/genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Transporte de Monossacarídeos/genética , Análise de Sequência de DNA/métodos , Xantomatose Cerebrotendinosa/diagnóstico
12.
Hum Mutat ; 42(8): 1005-1014, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34057271

RESUMO

Biallelic loss of function variants in TRIP11 encoding for the Golgi microtubule-associated protein 210 (GMAP-210) causes the lethal chondrodysplasia achondrogenesis type 1A (ACG1A). Loss of TRIP11 activity has been shown to impair Golgi structure, vesicular transport, and results in loss of IFT20 anchorage to the Golgi that is vital for ciliary trafficking and ciliogenesis. Here, we report four fetuses, two each from two families, who were ascertained antenatally with ACG1A. Affected fetuses in both families are homozygous for the deep intronic TRIP11 variant, c.5457+81T>A, which was found in a shared region of homozygosity. This variant was found to cause aberrant transcript splicing and the retention of 77 base pairs of intron 18. The TRIP11 messenger RNA and protein levels were drastically reduced in fibroblast cells derived from one of the affected fetuses. Using immunofluorescence we also detected highly compacted Golgi apparatus in affected fibroblasts. Further, we observed a significant reduction in the frequency of ciliated cells and in the length of primary cilia in subject-derived cell lines, not reported so far in patient cells with TRIP11 null or hypomorphic variants. Our findings illustrate how pathogenic variants in intronic regions of TRIP11 can impact transcript splicing, expression, and activity, resulting in ACG1A.


Assuntos
Acondroplasia , Osteocondrodisplasias , Acondroplasia/genética , Acondroplasia/patologia , Proteínas do Citoesqueleto/genética , Humanos , Mutação , Osteocondrodisplasias/genética , Osteocondrodisplasias/patologia
13.
Mol Genet Metab Rep ; 27: 100746, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33868930

RESUMO

Background Cystationine ß-synthase (CBS) deficiency is a genetic disorder characterized by severe hyperhomocysteinemia and thrombotic complications. In healthy individuals, physical exercise may result in a transient increase in plasma total homocysteine (tHcy) raising the possibility that exercise might be detrimental in CBS deficiency. Our main objective was to determine plasma tHcy kinetics in response to physical exercise in homocystinuria patients. Methods Six adult patients (2 males, 4 females) with homocystinuria and 6 age- and gender-matched controls completed a 30-min aerobic exercise of moderate-intensity with fixed power output (50 W for women and 100 W for men). Blood samples were drawn before, immediately, 180 min and 24 h after exercise. tHcy levels were determined by standard procedures; substrate oxidation and energy expenditure were measured using indirect calorimetry. Results Acute exercise was well tolerated and safe in patients and controls. During the exercise bout, heart rate and energy expenditure increased equally in both groups. tHcy levels were higher in patients compared to controls at all time points (p < 0.05). There was no significant effect of exercise on tHcy levels at any time point (p = 0.36). Although two patients with partial pyridoxine responsiveness presented higher homocysteine responses, their highest value remained below 55 µmol/l. Conclusions Overall metabolic responses to acute exercise were similar between homocystinuria patients and controls; specifically, exercise did not significantly change tHcy concentrations. Moderate physical exercise was well tolerated without any adverse event in our cohort of patients. Further studies are needed to identify the effects of different intensities and modes of exercise in larger cohorts of CBS patients with different levels of pyridoxine responsiveness.

14.
Mol Genet Metab Rep ; 26: 100719, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33659184

RESUMO

BACKGROUND: Classic cerebrotendinous xanthomatosis (CTX; OMIM #213700) manifests with chronic diarrhea, juvenile cataracts, tendon xanthomas and neurological symptoms. It is due to biallelic inactivation of CYP27A1 wich leads to cholestanol accumulation in the central nervous system, eyes and tendons. Less commonly, the disease can present in young adults as spastic paraparesis in the absence of xanthomas. CASE PRESENTATION: We report a 38-year old woman who presented with chronic diarrhea and progressive spastic paraparesis in her twenties. Brain magnetic resonance imaging (MRI) showed cerebral atrophy with diffuse periventricular white matter hyperintensities. Spinal MRI was normal. CYP27A1 gene sequencing confirmed the diagnosis of CTX. Chenodeoxycholic acid (CDCA) treatment was introduced with remission of diarrhea. Unfortunately, the treatment had to be discontinued several times and the patient developed psychosis and an severe ataxospastic gait. Spinal MRI revealed new linear hyperintensities of the corticospinal and gracile tracts. Thirty-three spinal CTX patients were identified by searching in Pubmed, EMBASE™ and Web of Science databases. All patients presented pyramidal signs and 48% had dorsal column signs. Juvenile cataracts were described in 78% of patients, chronic diarrhea in 65%, and tendon xanthomas in 31%. Disease improvement or stabilization with chenodeoxycholic acid was observed in 69% of patients. A higher prevalence of the Arg395Cys allele was observed in patients with spinal CTX as compared to CTX in general (ᵡ2; p < 0.00001). CONCLUSIONS: The diagnosis of spinal CTX can be easily missed or delayed in absence of xanthomas. There is a higher prevalence of the Arg395Cys allele in spinal CTX as compared to classic childhood-onset CTX. CDCA treatment seems to stabilize or improve clinical symptoms in most patients. However, as seen in our patient and in two previously reported cases, sudden interruption of CDCA may lead to irreversible neurological complications.

15.
Clin Genet ; 99(6): 780-788, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33586135

RESUMO

Four individuals from two families presented with a multisystemic condition of suspected genetic origin that was diagnosed only after genome analysis. The main phenotypic features were immune system dysregulation (severe immunodeficiency with autoimmunity) and intellectual disability. The four individuals were found to be homozygous for a 4.4 Kb deletion removing exons 20-23 (NM_003291.4) of the TPP2 gene, predicting a frameshift with premature termination of the protein. The deletion was located on a shared chromosome 13 haplotype indicating a Swiss founder mutation. Tripeptidyl peptidase 2 (TPP2) is a protease involved in HLA/antigen complex processing and amino acid homeostasis. Biallelic variants in TPP2 have been described in 10 individuals with variable features including immune deficiency, autoimmune cytopenias, and intellectual disability or chronic sterile brain inflammation mimicking multiple sclerosis. Our observations further delineate this severe condition not yet included in the OMIM catalog. Timely recognition of TPP2 deficiency is crucial since (1) immune surveillance is needed and hematopoietic stem cell transplantation may be necessary, and (2) for provision of genetic counselling. Additionally, enzyme replacement therapy, as already established for TPP1 deficiency, might be an option in the future.


Assuntos
Aminopeptidases/genética , Doenças Autoimunes/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Mutação da Fase de Leitura/genética , Síndromes de Imunodeficiência/genética , Serina Endopeptidases/genética , Adulto , Criança , Pré-Escolar , Éxons/genética , Feminino , Humanos , Masculino , Adulto Jovem
16.
Eur J Hum Genet ; 29(9): 1384-1395, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33594261

RESUMO

Decreased or increased activity of potassium channels caused by loss-of-function and gain-of-function (GOF) variants in the corresponding genes, respectively, underlies a broad spectrum of human disorders affecting the central nervous system, heart, kidney, and other organs. While the association of epilepsy and intellectual disability (ID) with variants affecting function in genes encoding potassium channels is well known, GOF missense variants in K+ channel encoding genes in individuals with syndromic developmental disorders have only recently been recognized. These syndromic phenotypes include Zimmermann-Laband and Temple-Baraitser syndromes, caused by dominant variants in KCNH1, FHEIG syndrome due to dominant variants in KCNK4, and the clinical picture associated with dominant variants in KCNN3. Here we review the presentation of these individuals, including five newly reported with variants in KCNH1 and three additional individuals with KCNN3 variants, all variants likely affecting function. There is notable overlap in the phenotypic findings of these syndromes associated with dominant KCNN3, KCNH1, and KCNK4 variants, sharing developmental delay and/or ID, coarse facial features, gingival enlargement, distal digital hypoplasia, and hypertrichosis. We suggest to combine the phenotypes and define a new subgroup of potassium channelopathies caused by increased K+ conductance, referred to as syndromic neurodevelopmental K+ channelopathies due to dominant variants in KCNH1, KCNK4, or KCNN3.


Assuntos
Anormalidades Múltiplas/genética , Canalopatias/genética , Anormalidades Craniofaciais/genética , Canais de Potássio Éter-A-Go-Go/genética , Fibromatose Gengival/genética , Mutação com Ganho de Função , Hallux/anormalidades , Deformidades Congênitas da Mão/genética , Deficiência Intelectual/genética , Unhas Malformadas/genética , Canais de Potássio/genética , Canais de Potássio Ativados por Cálcio de Condutância Baixa/genética , Polegar/anormalidades , Anormalidades Múltiplas/patologia , Adolescente , Adulto , Canalopatias/patologia , Criança , Anormalidades Craniofaciais/patologia , Feminino , Fibromatose Gengival/patologia , Hallux/patologia , Deformidades Congênitas da Mão/patologia , Humanos , Deficiência Intelectual/patologia , Masculino , Unhas Malformadas/patologia , Fenótipo , Polegar/patologia
17.
Biochem Pharmacol ; 185: 114452, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33545117

RESUMO

Diastrophic dysplasia (DTD) is a recessive chondrodysplasia caused by mutations in the SLC26A2 gene encoding for a sulfate/chloride transporter. When SLC26A2 is impaired intracellular level of sulfate is reduced leading to the synthesis of undersulfated proteoglycans. In normal chondrocytes, the main source of intracellular sulfate is the extracellular uptake through SLC26A2, but a small amount comes from the catabolism of sulfur-containing amino acids and other thiols. Here N-acetylcysteine (NAC), an extensively used drug, is proposed as alternative source of intracellular sulfate in an animal model of DTD (dtd mouse). Mutant and wild type mice were treated twice a day with hypodermic injections of 250 mg NAC/kg body weight for one week after birth. At the end of the treatment, an improvement trend in cartilage proteoglycan sulfation and in the skeletal phenotype of treated dtd mice were observed. Thus, a longer treatment lasted three weeks starting from birth was performed. Treated mutant mice showed a significant increase of cartilage proteoglycan sulfation and a relevant improvement of the skeletal phenotype based on measurements of several bony elements and bone quality by DEXA and micro CT. Moreover, the amelioration of the overall growth plate morphology in treated dtd mice suggested a partial rescue of the endochondral ossification process. Overall, the results prove that NAC is an effective source of intracellular sulfate for dtd mice in the postnatal period. This finding paves the way for a potential pharmacological treatment of DTD patients taking advantage from a drug repositioning strategy.


Assuntos
Acetilcisteína/administração & dosagem , Densidade Óssea/efeitos dos fármacos , Modelos Animais de Doenças , Nanismo/tratamento farmacológico , Nanismo/metabolismo , Fenótipo , Acetilcisteína/farmacocinética , Animais , Animais Recém-Nascidos , Densidade Óssea/fisiologia , Nanismo/diagnóstico por imagem , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/farmacocinética , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
19.
Am J Med Genet A ; 185(2): 517-527, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33398909

RESUMO

Bone dysplasias (osteochondrodysplasias) are a large group of conditions associated with short stature, skeletal disproportion, and radiographic abnormalities of skeletal elements. Nearly all are genetic in origin. We report a series of seven children with similar findings of chondrodysplasia and growth failure following early hematopoietic stem cell transplantation (HSCT) for pediatric non-oncologic disease: hemophagocytic lymphohistiocytosis or HLH (five children, three with biallelic HLH-associated variants [in PRF1 and UNC13D] and one with HLH secondary to visceral Leishmaniasis), one child with severe combined immunodeficiency and one with Omenn syndrome (both children had biallelic RAG1 pathogenic variants). All children had normal growth and no sign of chondrodysplasia at birth and prior to their primary disease. After HSCT, all children developed growth failure, with standard deviation scores for height at or below -3. Radiographically, all children had changes in the spine, metaphyses and epiphyses, compatible with a spondyloepimetaphyseal dysplasia. Genomic sequencing failed to detect pathogenic variants in genes associated with osteochondrodysplasias. We propose that such chondrodysplasia with growth failure is a novel, rare, but clinically important complication following early HSCT for non-oncologic pediatric diseases. The pathogenesis is unknown but could possibly involve loss or perturbation of the cartilage-bone stem cell population.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Linfo-Histiocitose Hemofagocítica/genética , Osteocondrodisplasias/genética , Criança , Pré-Escolar , Feminino , Humanos , Linfo-Histiocitose Hemofagocítica/complicações , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/terapia , Masculino , Proteínas de Membrana/genética , Osteocondrodisplasias/complicações , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/terapia , Perforina/genética , Resultado do Tratamento
20.
Genes (Basel) ; 13(1)2021 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-35052370

RESUMO

The term "arthrogryposis" is used to indicate multiple congenital contractures affecting two or more areas of the body. Arthrogryposis is the consequence of an impairment of embryofetal neuromuscular function and development. The causes of arthrogryposis are multiple, and in newborns, it is difficult to predict the molecular defect as well as the clinical evolution just based on clinical findings. We studied a consecutive series of 13 participants who had amyoplasia, distal arthrogryposis (DA), or syndromic forms of arthrogryposis with normal intellectual development and other motor abilities. The underlying pathogenic variants were identified in 11 out of 13 participants. Correlating the genotype with the clinical features indicated that prenatal findings were specific for DA; this was helpful to identify familial cases, but features were non-specific for the involved gene. Perinatal clinical findings were similar among the participants, except for amyoplasia. Dilatation of the aortic root led to the diagnosis of Loeys-Dietz syndrome (LDS) in one case. The phenotype of DA type 5D (DA5D) and Escobar syndrome became more characteristic at later ages due to more pronounced pterygia. Follow-up indicated that DA type 1 (DA1)/DA type 2B (DA2B) spectrum and LDS had a more favorable course than the other forms. Hand clenching and talipes equinovarus/rocker bottom foot showed an improvement in all participants, and adducted thumb resolved in all forms except in amyoplasia. The combination of clinical evaluation with Next Generation Sequencing (NGS) analysis in the newborn may allow for an early diagnosis and, particularly in the DAs, suggests a favorable prognosis.


Assuntos
Artrogripose/genética , Anormalidades Múltiplas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Túnica Conjuntiva/anormalidades , Feminino , Genótipo , Humanos , Síndrome de Loeys-Dietz/genética , Masculino , Hipertermia Maligna/genética , Pessoa de Meia-Idade , Mutação/genética , Linhagem , Fenótipo , Gravidez , Pterígio/genética , Anormalidades da Pele/genética
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