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1.
Am J Med Genet A ; 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729175

RESUMO

Infantile onset cardiomyopathies are highly heterogeneous with several phenocopies compared with adult cardiomyopathies. Multidisciplinary management is essential in determining the underlying etiology in children's cardiomyopathy. Elevated urinary excretion of 3-methylglutaconic acid (3-MGA) is a useful tool in identifying the etiology in some metabolic cardiomyopathy. Here, we report the delayed appearance of 3-MGA-uria, between 6 and 18 months in three patients (out of 100 childhood onset cardiomyopathy) with neonatal onset cardiomyopathy, secondary to TMEM70 mutations and TAZ mutations (Barth syndrome), in whom extensive metabolic investigations, performed in the first weeks of life, did not display 3-MGA-uria. Serial retrospective evaluations showed full characteristic features of TMEM70 and TAZ mutations (Barth syndrome) in these three patients, including a clearly abnormal monolysocardiolipin/cardiolipin ratio in the two Barth syndrome patients. Serially repeated metabolic investigations finally discovered the 3-MGA-uria biomarker in all three patients between the age of 6 and 18 months. Our observation provides novel insights into the temporal appearance of 3-MGA-uria in TMEM70 and TAZ mutations (Barth syndrome) and focus the importance of multidisciplinary management and careful evaluation of family history and red flag signs for phenocopies in infantile onset cardiomyopathies.

2.
Clin Genet ; 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31600839

RESUMO

Aymé-Gripp syndrome (AYGRPS) is a recognizable condition caused by a restricted spectrum of dominantly acting missense mutations affecting the transcription factor MAF. Major clinical features of AYGRPS include congenital cataracts, sensorineural hearing loss, intellectual disability, and a distinctive flat facial appearance. Skeletal abnormalities have also been observed in affected individuals, even though these features have not been assessed systematically. Expanding the series with four additional patients, here we provide a more accurate delineation of the molecular aspects and clinical phenotype, particularly focusing on the skeletal features characterizing this disorder. Apart from previously reported malar flattening and joint limitations, we document that carpal/tarsal and long bone defects, and hip dysplasia occur in affected subjects more frequently than formerly appreciated.

3.
Am J Med Genet A ; 179(10): 2083-2090, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31368652

RESUMO

Noonan syndrome (NS) is caused by mutations in more than 10 genes, mainly PTPN11, SOS1, RAF1, and RIT1. Congenital heart defects and cardiomyopathy (CMP) are associated with significant morbidity and mortality in NS. Although hypertrophic CMP has "classically" been reported in association to RAF1, RIT1, and PTPN11 variants, SOS1 appears to be poorly related to CMP. Patients with NS attending our Center from January 2013 to June 2018 were eligible for inclusion if they carried SOS1 variants and presented with-or developed-CMP. Literature review describing the co-existence of SOS1 mutation and CMP was also performed. We identified six patients with SOS1 variants and CMP (male to female ratio 2:1) including two novel variants. CMP spectrum encompassed: (a) dilated CMP, (b) nonobstructive hypertrophic CMPs, and (c) obstructive hypertrophic CMPs. Survival is 100%. Literature review included 16 SOS1 mutated in CMP. CMP, mainly hypertrophic, has been often reported in association to RAF1, RIT1, and PTPN11 variants. Differently from previous reports, due to the frequent association of SOS1 variants and CMP in our single center experience, we suggest potential underestimated proportion of SOS1 in pediatric CMPs.

4.
Curr Opin Gastroenterol ; 35(6): 491-498, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31464810

RESUMO

PURPOSE OF REVIEW: The 'precision medicine' refers to the generation of identification and classification criteria for advanced taxonomy of patients, exploiting advanced models to infer optimized clinical decisions for each disease phenotype. RECENT FINDINGS: The current article reviews new advances in the past 18 months on the microbiomics science intended as new discipline contributing to advanced 'precision medicine'. Recently published data highlight the importance of multidimensional data in the description of deep disease phenotypes, including microbiome and immune profiling, and support the efficacy of the systems medicine to better stratify patients, hence optimizing diagnostics, clinical management and response to treatments. SUMMARY: The articles referenced in this review help inform the reader on new decision-support systems that can be based on multiomics patients' data including microbiome and immune profiling. These harmonized and integrated data can be elaborated by artificial intelligence to generate optimized diagnostic pipelines and clinical interventions.

5.
Am J Med Genet A ; 179(8): 1570-1574, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31111652

RESUMO

"Apple peel" intestinal atresia is a rare form of small bowel atresia, in which the duodenum or proximal jejunum ends in a blind pouch and the distal small bowel wraps around its vascular supply, in a spiral resembling an apple peel. The etiology of "apple peel" intestinal atresia is presently unknown, although a congenital or acquired intestinal vascular accident can have a role in the pathogenesis. We report a family in which the proband affected by "apple peel" intestinal atresia, had a sibling (an interrupted pregnancy), and a paternal cousin with cardiac left-sided obstructive lesions. Molecular testing for NOTCH1 gene was carried out in the proband, because pathogenic mutations in this gene have been associated with familial and sporadic cardiac left-sided obstructive lesions and vascular anomalies, both isolated or within the spectrum of the Adams-Oliver syndrome (AOS). The heterozygous c.2734C>T (p.Arg912Trp) NOTCH1 variant was found in the proband with "apple peel" intestinal atresia and in his father. This result argues for a possible causal relationship between NOTCH1 gene mutations and some forms of intestinal defects, through a vascular mechanism. The spectrum of NOTCH1-associated malformations is widened. Genetic counseling should take into account intrafamilial variable clinical expression and incomplete penetrance.

6.
Am J Med Genet A ; 179(8): 1615-1621, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31145527

RESUMO

Only a few individuals with 12q15 deletion have been described, presenting with a disorder characterized by learning disability, developmental delay, nasal speech, and hypothyroidism. The smallest region of overlap for this syndrome was included in a genomic segment spanning CNOT2, KCNMB4, and PTPRB genes. We report on an additional patient harboring a 12q15 microdeletion encompassing only part of CNOT2 gene, presenting with a spectrum of clinical features overlapping the 12q15 deletion syndrome phenotype. We propose CNOT2 as the phenocritical gene for 12q15 deletion syndrome and its haploinsufficiency being associated with an autosomal dominant disorder, presenting with developmental delay, hypotonia, feeding problems, learning difficulties, nasal speech, skeletal anomalies, and facial dysmorphisms.

7.
Int J Mol Sci ; 20(6)2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30909440

RESUMO

To identify whether parent-of-origin effects (POE) of the 15q11.2 BP1-BP2 microdeletion are associated with differences in clinical features in individuals inheriting the deletion, we collected 71 individuals reported with phenotypic data and known inheritance from a clinical cohort, a research cohort, the DECIPHER database, and the primary literature. Chi-squared and Mann-Whitney U tests were used to test for differences in specific and grouped clinical symptoms based on parental inheritance and proband gender. Analyses controlled for sibling sets and individuals with additional variants of uncertain significance (VOUS). Among all probands, maternal deletions were associated with macrocephaly (p = 0.016) and autism spectrum disorder (ASD; p = 0.02), while paternal deletions were associated with congenital heart disease (CHD; p = 0.004). Excluding sibling sets, maternal deletions were associated with epilepsy as well as macrocephaly (p < 0.05), while paternal deletions were associated with CHD and abnormal muscular phenotypes (p < 0.05). Excluding sibling sets and probands with an additional VOUS, maternal deletions were associated with epilepsy (p = 0.019) and paternal deletions associated with muscular phenotypes (p = 0.008). Significant gender-based differences were also observed. Our results supported POEs of this deletion and included macrocephaly, epilepsy and ASD in maternal deletions with CHD and abnormal muscular phenotypes seen in paternal deletions.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Criança , Pré-Escolar , Aberrações Cromossômicas , Cromossomos Humanos Par 15/genética , Estudos de Coortes , Feminino , Impressão Genômica , Humanos , Masculino , Fenótipo , Fatores Sexuais , Irmãos
8.
Clin Genet ; 95(4): 525-531, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30684285

RESUMO

Whole exome sequencing (WES) has led to the understanding of the molecular events affecting neurodevelopment in an extremely diverse clinical context, including diseases with intellectual disability (ID) associated with variable central nervous system (CNS) malformations, and developmental and epileptic encephalopathies (DEEs). Recently, PACS2 mutations have been causally linked to a DEE with cerebellar dysgenesis and facial dysmorphism. All known patients presented with a recurrent de novo missense mutation, c.625G>A (p.Glu209Lys). Here, we report on a 7-year-old boy with DEE, cerebellar dysgenesis, facial dysmorphism and postnatal growth delay, apparently not fitting with any recognized disorder. WES disclosed a de novo novel missense PACS2 variant, c.631G>A (p.Glu211Lys), as the molecular cause of this complex phenotype. We provide a detailed clinical characterization of this patient, and analyse the available clinical data of individuals with PACS2 mutations to delineate more accurately the clinical spectrum associated with this recently described syndrome. Our study expands the clinical and molecular spectrum of PACS2 mutations. Overview of the available clinical data allow to delineate the condition associated with PACS2 mutations as a variable trait, in which the key features are represented by moderate to severe ID, cerebellar dysgenesis and other CNS malformations, reduced growth, and facial dysmorphism.

9.
J Clin Endocrinol Metab ; 104(6): 2163-2170, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30649436

RESUMO

CONTEXT: Nonalcoholic fatty liver disease (NAFLD) is being increasingly diagnosed at younger ages, pointing toward an early-life origin. OBJECTIVE: To evaluate the frequency and risk factors for bright liver (BL) in 1-year-old toddlers. DESIGN: Secondary analysis of the 1-year follow-up of the Feeding Study. Exposures were child PNPLA3 and TM6SF2 gene variants; child anthropometry at birth and at 1 year of follow-up; child subcutaneous, visceral, and epicardial adipose tissue at 1 year of follow-up; maternal anthropometry at the start and at the end of pregnancy; and maternal red blood cell fatty-acid composition at the third trimester of pregnancy. SETTING: General population. PARTICIPANTS: Among 505 mother-toddler pairs, 391 children (77%) underwent liver and abdominal ultrasonography at the 1-year follow-up. MAIN OUTCOME: BL as diagnosed by ultrasonography. RESULTS: Seventeen (4%) of 391 toddlers had BL. Compared with the toddlers with the PNPLA 3 CC genotype, the odds (95% CI) of BL were 3.01 (1.05 to 8.64, P < 0.05) times higher in those with the PNAPLA3 CG genotype and 5.37 (1.12 to 25.77, P < 0.05) higher in those with the PNPLA3 CC genotype. We found no association between BL status and TM6SF2. Body weight, body mass index, and maternal weight gain during pregnancy were higher in BL+ than in BL- children. Visceral adipose tissue was higher but subcutaneous adipose tissue and epicardial adipose tissue were similar in BL+ and BL- children. CONCLUSIONS: Four percent of the Feeding Study children had BL at 1 year of age. In line with expectations, PNAPLA3 was already a predictor of BL at this early age.

10.
Arthritis Rheumatol ; 71(6): 1000-1010, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30592383

RESUMO

OBJECTIVE: To assess the composition of gut microbiota in Italian and Dutch patients with juvenile idiopathic arthritis (JIA) at baseline, with inactive disease, and with persistent activity compared to healthy controls. METHODS: In a multicenter, prospective, observational cohort study, fecal samples were collected at baseline from 78 Italian and 21 Dutch treatment-naive JIA patients with <6 months of disease duration and compared to 107 geographically matched samples from healthy children. Forty-four follow-up samples from patients with inactive disease and 25 follow-up samples from patients with persistent activity were analyzed. Gut microbiota composition was determined by 16S ribosomal RNA-based metagenomics. Alpha- and ß-diversity were computed, and log ratios of relative abundance were compared between patients and healthy controls using random forest models and logistic regression. RESULTS: Baseline samples from Italian patients showed reduced richness compared to healthy controls (P < 0.001). Random forest models distinguished between Italian patient baseline samples and healthy controls and suggested differences between Dutch patient samples and healthy controls (areas under the curve >0.99 and 0.71, respectively). The operational taxonomic units (OTUs) of Erysipelotrichaceae (increased in patients), Allobaculum (decreased in patients), and Faecalibacterium prausnitzii (increased in patients) showed different relative abundance in Italian patient baseline samples compared to controls after controlling for multiple comparisons. Some OTUs differed between Dutch patient samples and healthy controls, but no evidence remained after controlling for multiple comparisons. No differences were found in paired analysis between Italian patient baseline and inactive disease samples. CONCLUSION: Our findings show evidence for dysbiosis in JIA patients. Only patient/control status, age, and geographic origin appear to be drivers of the microbiota profiles, regardless of disease activity stage, inflammation, and markers of autoimmunity.

11.
PLoS One ; 13(12): e0208171, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30521551

RESUMO

BACKGROUND: Cystic fibrosis (CF) is a disorder affecting the respiratory, digestive, reproductive systems and sweat glands. This lethal hereditary disease has known or suspected links to the dysbiosis gut microbiota. High-throughput meta-omics-based approaches may assist in unveiling this complex network of symbiosis modifications. OBJECTIVES: The aim of this study was to provide a predictive and functional model of the gut microbiota enterophenotype of pediatric patients affected by CF under clinical stability. METHODS: Thirty-one fecal samples were collected from CF patients and healthy children (HC) (age range, 1-6 years) and analysed using targeted-metagenomics and metabolomics to characterize the ecology and metabolism of CF-linked gut microbiota. The multidimensional data were low fused and processed by chemometric classification analysis. RESULTS: The fused metagenomics and metabolomics based gut microbiota profile was characterized by a high abundance of Propionibacterium, Staphylococcus and Clostridiaceae, including Clostridium difficile, and a low abundance of Eggerthella, Eubacterium, Ruminococcus, Dorea, Faecalibacterium prausnitzii, and Lachnospiraceae, associated with overexpression of 4-aminobutyrate (GABA), choline, ethanol, propylbutyrate, and pyridine and low levels of sarcosine, 4-methylphenol, uracil, glucose, acetate, phenol, benzaldehyde, and methylacetate. The CF gut microbiota pattern revealed an enterophenotype intrinsically linked to disease, regardless of age, and with dysbiosis uninduced by reduced pancreatic function and only partially related to oral antibiotic administration or lung colonization/infection. CONCLUSIONS: All together, the results obtained suggest that the gut microbiota enterophenotypes of CF, together with endogenous and bacterial CF biomarkers, are direct expression of functional alterations at the intestinal level. Hence, it's possible to infer that CFTR impairment causes the gut ecosystem imbalance.This new understanding of CF host-gut microbiota interactions may be helpful to rationalize novel clinical interventions to improve the affected children's nutritional status and intestinal function.

12.
Cytogenet Genome Res ; 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30372694

RESUMO

Interstitial deletions of the long arm of chromosome 20 are very rare, with only 12 reported patients harboring the 20q11.2 microdeletion and presenting a disorder characterized by psychomotor and growth delay, dysmorphisms, and brachy-/clinodactyly. We describe the first case of mosaic 20q11.2 deletion in a 5-year-old girl affected by mild psychomotor delay, feeding difficulties, growth retardation, craniofacial dysmorphisms, and finger anomalies. SNP array analysis disclosed 20% of cells with a 20q11.21q12 deletion, encompassing the 20q11.2 minimal critical region and the 3 OMIM disease-causing genes GDF5, EPB41L1, and SAMHD1. We propose a pathogenic role of other genes mapping outside the small region of overlap, in particular GHRH (growth hormone releasing hormone), whose haploinsufficiency could be responsible for the prenatal onset of growth retardation which is shared by half of these patients. Our patient highlights the utility of chromosomal microarray analysis to identify low-level mosaicism.

13.
Am J Hum Genet ; 103(4): 621-630, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30290154

RESUMO

Aberrant activation or inhibition of potassium (K+) currents across the plasma membrane of cells has been causally linked to altered neurotransmission, cardiac arrhythmias, endocrine dysfunction, and (more rarely) perturbed developmental processes. The K+ channel subfamily K member 4 (KCNK4), also known as TRAAK (TWIK-related arachidonic acid-stimulated K+ channel), belongs to the mechano-gated ion channels of the TRAAK/TREK subfamily of two-pore-domain (K2P) K+ channels. While K2P channels are well known to contribute to the resting membrane potential and cellular excitability, their involvement in pathophysiological processes remains largely uncharacterized. We report that de novo missense mutations in KCNK4 cause a recognizable syndrome with a distinctive facial gestalt, for which we propose the acronym FHEIG (facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, and gingival overgrowth). Patch-clamp analyses documented a significant gain of function of the identified KCNK4 channel mutants basally and impaired sensitivity to mechanical stimulation and arachidonic acid. Co-expression experiments indicated a dominant behavior of the disease-causing mutations. Molecular dynamics simulations consistently indicated that mutations favor sealing of the lateral intramembrane fenestration that has been proposed to negatively control K+ flow by allowing lipid access to the central cavity of the channel. Overall, our findings illustrate the pleiotropic effect of dysregulated KCNK4 function and provide support to the hypothesis of a gating mechanism based on the lateral fenestrations of K2P channels.

14.
Am J Med Genet A ; 2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30289615

RESUMO

DCPS gene encodes for a protein involved in gene expression regulation through promoting cap degradation during mRNA decapping processes. Mutations altering the DCPS function have been associated to a distinct disorder, Al-Raqad syndrome, so far described only in two families. We report on a patient harboring a novel homozygous missense mutation in DCPS, presenting with growth retardation, craniofacial anomalies, skin dyschromia, and neuromuscular defects. This case study explains the molecular spectrum of DCPS mutations and might contribute to the phenotypic delineation of this rare condition.

15.
Am J Med Genet A ; 2018 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-30244530

RESUMO

Wolf-Hirschhorn syndrome is a well-defined disorder due to 4p16.3 deletion, characterized by distinct facial features, intellectual disability, prenatal and postnatal growth retardation, and seizures. Genotype-phenotype correlations based on differently sized deletions have been attempted, and some candidate genes have been suggested. We report on clinical characteristics of three patients with pure interstitial submicroscopic 4p16.3 deletions, ranging in size from 68 to 166 kb, involving WHSCR1 and/or part of WHSCR2, and review published cases with overlapping 4p16.3 losses. The present study highlights a major role of NSD2 gene in the pathogenesis of the WHS main features and predicts that loss-of-function mutations affecting NSD2 gene could result in microcephaly, prenatal and postnatal growth retardation, psychomotor and language delay, and craniofacial features. Absent seizures in all subjects corroborate the suggestion that this specific feature is causally linked with at least one additional causative gene. Finally, we suggest that mir-943 could play a role in the pathogenesis of CHD in some of these patients.

16.
Eur J Med Genet ; 2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-30189253

RESUMO

TARP syndrome (TARPS) is an X-linked syndromic condition including Robin sequence, congenital heart defects, developmental delay, feeding difficulties and talipes equinovarus, as major features. The disease is caused by inactivating mutations in RBM10 which encodes for a RNA binding motif protein involved in transcript processing. We herein report a male born from healthy and non-consanguineous parents, presenting prenatal record of intrauterine fetal growth retardation, and postnatal features including growth and developmental delays, CNS abnormalities, facial dysmorphisms, bilateral syndactyly at the hands, talipes equinovarus and congenital heart defects. By using trio-based Whole Exome Sequencing approach, a maternally inherited RBM10 frameshift variant causing decay of the RBM10 transcript was identified. Despite the syndrome is considered lethal in affected males, our subject with molecularly confirmed TARPS is still alive at 11 years of age supporting the chance of surviving. Long-term surviving in TARPS is extremely rare and should be considered in genetic counselling and clinical follow up of the syndrome. We provide the natural history of the syndrome, reviewing the major clinical characteristics. Congenital heart defects are confirmed as specific diagnostic markers for the syndrome. In addition, cardiac anatomical details are defining a possible clinical overlap with syndromic conditions related to the hedgehog pathway and/or primary cilium anomalies as Oral-Facial-Digital or Smith-Lemli-Opitz syndromes.

17.
Am J Hum Genet ; 103(2): 305-316, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30057029

RESUMO

Next-generation sequencing combined with international data sharing has enormously facilitated identification of new disease-associated genes and mutations. This is particularly true for genetically extremely heterogeneous entities such as neurodevelopmental disorders (NDDs). Through exome sequencing and world-wide collaborations, we identified and assembled 20 individuals with de novo variants in FBXO11. They present with mild to severe developmental delay associated with a range of features including short (4/20) or tall (2/20) stature, obesity (5/20), microcephaly (4/19) or macrocephaly (2/19), behavioral problems (17/20), seizures (5/20), cleft lip or palate or bifid uvula (3/20), and minor skeletal anomalies. FBXO11 encodes a member of the F-Box protein family, constituting a subunit of an E3-ubiquitin ligase complex. This complex is involved in ubiquitination and proteasomal degradation and thus in controlling critical biological processes by regulating protein turnover. The identified de novo aberrations comprise two large deletions, ten likely gene disrupting variants, and eight missense variants distributed throughout FBXO11. Structural modeling for missense variants located in the CASH or the Zinc-finger UBR domains suggests destabilization of the protein. This, in combination with the observed spectrum and localization of identified variants and the lack of apparent genotype-phenotype correlations, is compatible with loss of function or haploinsufficiency as an underlying mechanism. We implicate de novo missense and likely gene disrupting variants in FBXO11 in a neurodevelopmental disorder with variable intellectual disability and various other features.

18.
Int J Cardiol ; 268: 100-105, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30041775

RESUMO

BACKGROUND: Heterotaxy syndrome (HS) is a group of congenital disorders characterized by abnormal arrangement of thoraco-abdominal organs across the left-right axis of the body, classified as right (RAI) and left atrial isomerism (LAI)·We investigated the long-term survival and phenotypic spectrum in our HS cohort. Results are compared to literature data. METHODS: This is a single centre, observational, both retro and prospective study. Cardiac features, surgical management and abdominal ultrasound (US) of all HS patients were reviewed or investigated if missing. We evaluated all anatomical data and their clinical impact on survival, arrhythmias, infections, and heart transplant (HT). RESULTS: 136 patients were classified as RAI (81) and LAI (55). Long-term survival and freedom from HT reached 69.8% and 87.8% at 40 years in RAI and LAI, respectively. Multivariate analysis showed that LAI is an independent predictor for pacemaker implantation (p = 0.019). Splenic status varied in both groups: in RAI, abdominal US showed asplenia, polysplenia and normal spleen in 48%, 4% and 32% of patients, respectively, whereas in LAI polysplenia, asplenia and normal spleen occurred in 64%, 4% and 16% of cases, respectively. CONCLUSIONS: Mortality was significantly lower (9%) compared to literature (50%). Although patients with RAI experienced a higher mortality, no independent predictors were found. We demonstrated that the obsolete cardiac definition of "asplenia" and "polysplenia" instead of RAI and LAI is misleading, because of the high variability of the splenic phenotype among patients of both groups.

19.
Hum Mutat ; 39(10): 1428-1441, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30007050

RESUMO

Atrioventricular septal defect (AVSD) may occur as part of a complex disorder (e.g., Down syndrome, heterotaxy), or as isolate cardiac defect. Multiple lines of evidence support a role of calcineurin/NFAT signaling in AVSD, and mutations in CRELD1, a protein functioning as a regulator of calcineurin/NFAT signaling have been reported in a small fraction of affected subjects. In this study, 22 patients with isolated AVSD and 38 with AVSD and heterotaxy were screened for NFATC1 gene mutations. Sequence analysis identified three missense variants in three individuals, including a subject with isolated AVSD [p.(Ala367Val)], an individual with AVSD and heterotaxy [p.(Val210Met)], and a subject with AVSD, heterotaxy, and oculo-auriculo-vertebral spectrum (OAVS) [p.(Ala696Thr)], respectively. The latter was also heterozygous for a missense change in TBX1 [p.(Pro86Leu)]. Targeted resequencing of genes associated with AVSD, heterotaxy, or OAVS excluded additional hits in the three mutation-positive subjects. Functional characterization of NFATC1 mutants documented defective nuclear translocation and decreased transcriptional transactivation activity. When expressed in zebrafish, the three NFATC1 mutants caused cardiac looping defects and altered atrioventricular canal patterning, providing evidence of their functional relevance in vivo. Our findings support a role of defective NFATC1 function in the etiology of isolated and heterotaxy-related AVSD.

20.
Eur J Med Genet ; 2018 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30048822

RESUMO

GPC3 and GPC4 are the only two genes in which mutations are known to cause Simpson-Golabi-Behmel syndrome type 1 (SGBS1). The majority of SGBS1 patients have point mutations or deletions in GPC3. Only one SGBS1 family has been reported with duplication of both GPC3 and GPC4. Although clinical presentation of SGBS1 in affected males is well defined, the phenotype in female carriers is less clear. In total, six female carriers with clinical expression of SGBS1 have been reported to date. In this study, we provide description of two families with rare duplications in both GPC3 and GPC4. These imbalances resulted in SGBS1 in males, while female carriers with skewed X-inactivation exhibited significant features of SGBS1 including congenital heart defect, hernias, intellectual disability and coarse facial features. In family 2, a SGBS diagnosis was not considered in the father until after the diagnosis had been first considered and made in the affected daughter. We emphasize on the importance of testing at risk females and careful examination of those who are found to be carriers of SGBS1. We also discuss and provide supportive evidence for the role of skewed X-inactivation in clinical expression of SGBS1 in female carriers.

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