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1.
Hum Mol Genet ; 31(9): 1389-1406, 2022 05 04.
Article in English | MEDLINE | ID: mdl-34761259

ABSTRACT

Autism spectrum disorder (ASD) and intellectual disability (ID) often exist together in patients. The RAB39B gene has been reported to be mutated in ID patients with additional clinical features ranging from ASD, macrocephaly, seizures and/or early-onset parkinsonism. Here, we describe a novel RAB39B nonstop mutation [Xq28; c.640 T > C; p.(*214Glnext*21)] in a family with ASD, severe ID and poor motor coordination, and we assessed the pathogenicity of the mutation. A heterologous cell system and a Rab39b knockdown (KD) murine model, which mimic the nonstop mutation, were used to validate the deleterious effect of the RAB39B mutation. The mutation led to RAB39B protein instability, resulting in its increased degradation and consequent downregulation. Using a Rab39b KD mouse model, we demonstrated that the downregulation of RAB39B led to increased GluA2 lacking Ca2+-permeable AMPAR composition at the hippocampal neuronal surface and increased dendritic spine density that remained in an immature filopodia-like state. These phenotypes affected behavioural performance in a disease-specific manner. Rab39b KD mice revealed impaired social behaviour but intact social recognition. They also showed normal anxiety-like, exploratory and motivational behaviours but impaired working and associative memories. In conclusion, we found a novel RAB39B nonstop variant that segregated in a family with a clinical phenotype including ID, ASD and poor motor coordination. The pathogenicity of mutations causing the downregulation of RAB39B proteins, impacting AMPAR trafficking and dendritic spine morphogenesis, reinforced the idea that AMPAR modulation and dendritic spine assets could be considered hallmarks of neurodevelopmental disorders.


Subject(s)
Autism Spectrum Disorder , Intellectual Disability , Animals , Autism Spectrum Disorder/genetics , Disease Models, Animal , Down-Regulation , Humans , Intellectual Disability/genetics , Mice , Mutation , rab GTP-Binding Proteins/genetics , rab GTP-Binding Proteins/metabolism
2.
Prenat Diagn ; 42(13): 1575-1586, 2022 12.
Article in English | MEDLINE | ID: mdl-36403097

ABSTRACT

OBJECTIVES: To establish the positive predictive values (PPV) of cfDNA testing based on data from a nationwide survey of independent clinical cytogenetics laboratories. METHODS: Prenatal diagnostic test results obtained by Italian laboratories between 2013 and March 2020 were compiled for women with positive non-invasive prenatal tests (NIPT), without an NIPT result, and cases where there was sex discordancy between the NIPT and ultrasound. PPV and other summary data were reviewed. RESULTS: Diagnostic test results were collected for 1327 women with a positive NIPT. The highest PPVs were for Trisomy (T) 21 (624/671, 93%) and XYY (26/27, 96.3%), while rare autosomal trisomies (9/47, 19.1%) and recurrent microdeletions (8/55, 14.5%) had the lowest PPVs. PPVs for T21, T18, and T13 were significantly higher when diagnostic confirmation was carried out on chorionic villi (97.5%) compared to amniotic fluid (89.5%) (p < 0.001). In 19/139 (13.9%), of no result cases, a cytogenetic abnormality was detected. Follow-up genetic testing provided explanations for 3/6 cases with a fetal sex discordancy between NIPT and ultrasound. CONCLUSIONS: NIPT PPVs differ across the conditions screened and the tissues studied in diagnostic testing. This variability, issues associated with fetal sex discordancy, and no results, illustrate the importance of pre- and post-test counselling.


Subject(s)
Cell-Free Nucleic Acids , Female , Humans , Pregnancy , Cytogenetic Analysis , Predictive Value of Tests , Prenatal Diagnosis/methods , Trisomy/diagnosis , Trisomy/genetics , Trisomy 13 Syndrome/diagnosis , Trisomy 18 Syndrome/diagnosis , Italy
3.
Adv Neonatal Care ; 22(2): 125-131, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-33852449

ABSTRACT

BACKGROUND: Filamin A (FLNA) is an intracellular actin-binding protein, encoded by the FLNA gene, with a wide tissue expression. It is involved in several cellular functions, and extracellular matrix structuring. FLNA gene alterations lead to diseases with a wide phenotypic spectrum, such as brain periventricular nodular heterotopia (PVNH), cardiovascular abnormalities, skeletal dysplasia, and lung involvement. CLINICAL FINDINGS: We present the case of a female infant who showed at birth aortic valve stenosis and PVNH, and subsequently developed interstitial lung disease with severe pulmonary hypertension. PRIMARY DIAGNOSIS: The association of aortic valve dysplasia, left ventricular outflow obstruction, persistent patent ductus arteriosus, and brain heterotopic gray matter suggested a possible FLNA gene alteration. A novel heterozygous intronic variant in the FLNA gene (NM_001110556.1), c.4304-1G >A, was detected. INTERVENTIONS: In consideration of valve morphology and severity of stenosis, the neonate was scheduled for a transcatheter aortic valvuloplasty. At 3 months of life, she developed hypoxemic respiratory failure with evidence of severe pulmonary hypertension. Inhaled nitric oxide (iNO) and milrinone on continuous infusion were started. Because of a partial response to iNO, an intravenous continuous infusion of sildenafil was introduced. OUTCOMES: In consideration of severe clinical course and fatal outcome, the new FLNA gene mutation described in our patient seems to be associated with a loss of function of FLNA. PRACTICE RECOMMENDATIONS: Lung and brain involvement, in association with left ventricular outflow obstruction and persistent patency of ductus arteriosus, should be considered highly suggestive of FLNA gene alterations, in a female newborn.


Subject(s)
Hypertension, Pulmonary , Periventricular Nodular Heterotopia , Ventricular Outflow Obstruction , Brain/diagnostic imaging , Female , Filamins/genetics , Humans , Hypertension, Pulmonary/genetics , Infant , Infant, Newborn , Lung/diagnostic imaging , Mutation , Periventricular Nodular Heterotopia/genetics
4.
Clin Genet ; 99(3): 425-429, 2021 03.
Article in English | MEDLINE | ID: mdl-33236357

ABSTRACT

mTOR dysregulation has been described in pathological conditions, such as cardiovascular and overgrowth disorders. Here we report on the first case of a patient with a complex congenital heart disease and an interstitial duplication in the short arm of chromosome 1, encompassing part of the mTOR gene. Our results suggest that an intragenic mTOR microduplication might play a role in the pathogenesis of non-syndromic congenital heart defects (CHDs) due to an upregulation of mTOR/Rictor and consequently an increased phosphorylation of PI3K/AKT and MEK/ERK signaling pathways in patient-derived amniocytes. This is the first report which shows a causative role of intragenic mTOR microduplication in the etiology of an isolated complex CHD.


Subject(s)
Genetic Predisposition to Disease , Heart Defects, Congenital/genetics , Heart Defects, Congenital/metabolism , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism , Chromosomes, Human, Pair 1 , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , Heart Defects, Congenital/diagnosis , Humans , Infant , Mitogen-Activated Protein Kinase Kinases/metabolism , Mutation , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Up-Regulation
5.
Am J Med Genet A ; 185(6): 1897-1902, 2021 06.
Article in English | MEDLINE | ID: mdl-33750022

ABSTRACT

RASopathies are a group of syndromes with partially overlapping clinical features caused by germline mutations of the RAS/MAPK signaling pathway genes. The most common disorder is Noonan syndrome (NS; MIM 163950). We report the first prenatal case of NS with SOS2 (NM_006939.4) mutation in a euploid fetus with a severe increase in nuchal translucency (NT > 12 mm). Trio-based custom next-generation sequencing detected a de novo heterozygous missense mutation in the SOS2 gene: c.800 T > A (p.Met267Lys). Owing to the marked variable expressivity of NS and the scarcity of SOS2 mutation-related NS cases reported in the literature, it is difficult to provide appropriate genetic counseling. Several issues such as the best management technique and optimal NT cutoff have been discussed. In addition, in general, the fine balance between the advantages of an early prenatal diagnosis and the challenge of determining if the detected gene variant is pathogenic and, primarily, the stress of the counselees when providing a genetic counseling with limited information on the prenatal phenotype have been discussed. A prenatal path comprising examinations and multidisciplinary counseling is essential to support couples in a shared decision-making process.


Subject(s)
Early Diagnosis , Genetic Predisposition to Disease , Noonan Syndrome/diagnosis , Son of Sevenless Proteins/genetics , Female , Fetus/diagnostic imaging , Fetus/pathology , Genetic Counseling , Humans , Male , Mutation, Missense , Noonan Syndrome/diagnostic imaging , Noonan Syndrome/genetics , Noonan Syndrome/pathology , Pedigree , Prenatal Diagnosis
6.
Medicina (Kaunas) ; 57(12)2021 Dec 10.
Article in English | MEDLINE | ID: mdl-34946295

ABSTRACT

Background: Cleidocranial dysplasia (CCD) is a rare, autosomal dominant skeletal dysplasia with a prevalence of one per million births. The main causes of CCD are mutations in the core-binding factor alpha-1 (CBFA1) or runt-related transcription factor-2 (RUNX2), located at the 6p21 chromosomal region. RUNX2 plays important roles in osteoblast differentiation, chondrocyte proliferation and differentiation, and tooth formation. The disease is characterized by clavicular aplasia or hypoplasia, Wormian bones, delayed closure of cranial suture, brachycephalic head, maxillary deficiency, retention of primary teeth, inclusion of permanent teeth, and multiple supernumerary teeth. Materials and Methods: A 22-year-old girl suffering from cleidocranial dysplasia with short stature, narrow shoulders, craniofacial manifestations (short face, broad forehead, etc.) and dental anomalies (different lower dental elements under eruption, supernumerary and impacted multiple teeth, etc.) was examined at our service (Complex Operative Unit of Odontostomatology of Policlinico of Bari). RX Orthopantomography (OPG) and cone beam computed tomography (CBCT) were requested to better assess the position of the supernumerary teeth and their relationships with others and to evaluate the bone tissue. Results: Under eruption was probably caused by dental interferences with supernumerary teeth; hence, extractions of supernumerary upper canines and lower premolars were performed under general anaesthesia. Surgery outcome was excellent with good tissue healing and improvements in the therapeutic possibilities with future orthodontics. Conclusions: The objective of this article is to give an update about radiological, clinical, and molecular features of CCD and to alert the health team about the importance of establishing an early diagnosis and an appropriate treatment in these patients to prevent impacted teeth complications and to offer them a better quality of life.


Subject(s)
Cleidocranial Dysplasia , Tooth, Impacted , Tooth, Supernumerary , Adult , Cleidocranial Dysplasia/genetics , Female , Humans , Quality of Life , Radiography, Panoramic , Tooth, Impacted/diagnostic imaging , Tooth, Impacted/genetics , Tooth, Impacted/surgery , Tooth, Supernumerary/diagnostic imaging , Tooth, Supernumerary/genetics , Tooth, Supernumerary/surgery , Young Adult
7.
Prenat Diagn ; 40(11): 1474-1481, 2020 10.
Article in English | MEDLINE | ID: mdl-33034897

ABSTRACT

OBJECTIVE: To examine the incidence and type of chromosomal abnormalities in fetuses with first trimester ultrasound anomalies and a low-risk cfDNA test for common trisomies. METHODS: In 486 singleton pregnancies undergoing invasive testing after combined screening, a detailed first trimester ultrasound assessment was carried out and a maternal blood sample was sent for cfDNA analysis. Ultrasound and cfDNA data were analyzed in relation to fetal karyotype. RESULTS: Invasive testing demonstrated a chromosomal abnormality in 157 (32.3%) of 486 fetuses. In 348 cases with a low-risk cfDNA test for common trisomies, NT ≥ 3.5 mm and/or a major structural defect were observed in 92 (26.4%) fetuses. A chromosomal abnormality was found in 17 (18.5%; 95%CI 10.55-26.41) of these pregnancies, including 1 (1.1%) case of trisomy 21 and 16 (17.4%) fetuses with abnormalities different from common trisomies. The respective incidence in the 256 cases with a low-risk cfDNA test result and no ultrasound anomalies was 2.3% (95% CI 0.49-4.20; n = 6). CONCLUSIONS: In fetuses with first trimester ultrasound anomalies and a low-risk cfDNA result for trisomy 21, 18 and 13, diagnostic testing should be offered with the main objective to detect chromosomal abnormalities beyond common trisomies.


Subject(s)
Chromosome Aberrations/statistics & numerical data , Congenital Abnormalities/genetics , Nuchal Translucency Measurement , Adult , Cell-Free Nucleic Acids/analysis , Congenital Abnormalities/diagnostic imaging , Female , Humans , Middle Aged , Pregnancy , Pregnancy Trimester, First , Prospective Studies , Trisomy/diagnosis , Young Adult
8.
Clin Genet ; 95(1): 165-171, 2019 01.
Article in English | MEDLINE | ID: mdl-30288735

ABSTRACT

Biallelic exostosin-2 (EXT2) pathogenic variants have been described as the cause of the Seizures-Scoliosis-Macrocephaly syndrome (OMIM 616682) characterized by intellectual disability, facial dysmorphisms and seizures. More recently, it has been proposed to rename this disorder with the acronym AREXT2 (autosomal recessive EXT2-related syndrome). Here, we report the third family affected by AREXT2 syndrome, harboring compound missense variants in EXT2, p.Asp227Asn, and p.Tyr608Cys. In addition, our patients developed multiple exostoses, which were not observed in the previously described families. AREXT2 syndrome can be considered as a multiorgan Congenital Disorder of Glycosylation caused by a significant, but non-lethal, decrease in EXT2 expression, thereby affecting the synthesis of the heparan sulfate proteoglycans, which is relevant in many physiological processes. Our finding expands the clinical and molecular spectrum of the AREXT2 syndrome and suggests a possible genotype/phenotype correlation in the development of the exostoses.


Subject(s)
Exostoses, Multiple Hereditary/genetics , Intellectual Disability/genetics , N-Acetylglucosaminyltransferases/genetics , Seizures/genetics , Adult , Echocardiography , Exostoses, Multiple Hereditary/diagnostic imaging , Exostoses, Multiple Hereditary/physiopathology , Female , Genetic Predisposition to Disease , Humans , Infant , Intellectual Disability/diagnostic imaging , Intellectual Disability/physiopathology , Male , Mutation, Missense/genetics , Pedigree , Seizures/diagnostic imaging , Seizures/physiopathology , Young Adult
9.
Int J Mol Sci ; 18(6)2017 May 23.
Article in English | MEDLINE | ID: mdl-28545230

ABSTRACT

The stromal vascular cell fraction (SVF) of visceral and subcutaneous adipose tissue (VAT and SAT) has increasingly come into focus in stem cell research, since these compartments represent a rich source of multipotent adipose-derived stem cells (ASCs). ASCs exhibit a self-renewal potential and differentiation capacity. Our aim was to study the different expression of the embryonic stem cell markers NANOG (homeobox protein NANOG), SOX2 (SRY (sex determining region Y)-box 2) and OCT4 (octamer-binding transcription factor 4) and to evaluate if there exists a hierarchal role in this network in ASCs derived from both SAT and VAT. ASCs were isolated from SAT and VAT biopsies of 72 consenting patients (23 men, 47 women; age 45 ± 10; BMI between 25 ± 5 and 30 ± 5 range) undergoing elective open-abdominal surgery. Sphere-forming capability was evaluated by plating cells in low adhesion plastic. Stem cell markers CD90, CD105, CD29, CD31, CD45 and CD146 were analyzed by flow cytometry, and the stem cell transcription factors NANOG, SOX2 and OCT4 were detected by immunoblotting and real-time PCR. NANOG, SOX2 and OCT4 interplay was explored by gene silencing. ASCs from VAT and SAT confirmed their mesenchymal stem cell (MSC) phenotype expressing the specific MSC markers CD90, CD105, NANOG, SOX2 and OCT4. NANOG silencing induced a significant OCT4 (70 ± 0.05%) and SOX2 (75 ± 0.03%) downregulation, whereas SOX2 silencing did not affect NANOG gene expression. Adipose tissue is an important source of MSC, and siRNA experiments endorse a hierarchical role of NANOG in the complex transcription network that regulates pluripotency.


Subject(s)
Adipose Tissue/cytology , Nanog Homeobox Protein/metabolism , Adult , Cell Differentiation/genetics , Cell Differentiation/physiology , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Female , Humans , Male , Middle Aged , Nanog Homeobox Protein/genetics , Octamer Transcription Factor-3/genetics , Octamer Transcription Factor-3/metabolism , Real-Time Polymerase Chain Reaction , SOXB1 Transcription Factors/genetics , SOXB1 Transcription Factors/metabolism
10.
Am J Med Genet A ; 170(7): 1884-8, 2016 07.
Article in English | MEDLINE | ID: mdl-27148860

ABSTRACT

Chromosome 14q11-q22 deletion syndrome (OMIM 613457) is a rare genomic disorder whose associated phenotype is heterogeneous, depending on the size, and, mostly, on the deleted region. We report the clinical and molecular characterization of a female newborn, whose phenotype was characterized by poor growth, dysmorphic facial features, subclinical hypothyroidism, and mild reduction of CD3CD8 Lymphocytes with increased CD4/CD8 ratio. By array-CGH, we identified a 4.08 de novo interstitial deletion of the 14q13.2q21.1 region, which includes 16 OMIM genes.Our patient phenotype is compared with other published cases, for a better classification of the 14q11-q22 deletion syndrome. We demonstrated that the 14q13.2q21.1 deletion, which encompasses NKX2-1, but not FOXG1 gene and HPE8 region, identifies a well defined, more benign, microdeletion syndrome. This report confirms that an early identification with accurate characterization of the genomic disorders is of great relevance, enabling proper genetic counseling of the reproductive risk, as well as disease prognosis, and patient management. © 2016 Wiley Periodicals, Inc.


Subject(s)
Chromosome Deletion , Forkhead Transcription Factors/genetics , Hypothyroidism/genetics , Nerve Tissue Proteins/genetics , Nuclear Proteins/genetics , Transcription Factors/genetics , Chromosomes, Human, Pair 14/genetics , Comparative Genomic Hybridization , Face/physiopathology , Female , Humans , Hypothyroidism/physiopathology , In Situ Hybridization, Fluorescence , Infant, Newborn , Lymphocytes/pathology , Male , Phenotype , Thyroid Nuclear Factor 1
11.
Biochim Biophys Acta ; 1843(4): 675-84, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24389246

ABSTRACT

A study is presented on the expression of mitochondrial oxidative phosphorylation complexes in exponentially growing and serum-starved, quiescent human fibroblast cultures. The functional levels of respiratory complexes I and III and complex V (adenosine triphosphate (ATP) synthase) were found to be severely depressed in serum-starved fibroblasts. The depression of oxidative phosphorylation system (OXPHOS) complexes was associated with reduced levels of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and the down-stream nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factors (TFAM). In serum-starved fibroblasts decrease of the catalytic activity of AMP cyclic dependent protein kinase (PKA) and phosphorylation of cAMP response element-binding protein (CREB), the transcription coactivator of the PGC-1α gene, was found. Hydroxytyrosol prevented the decline in the expression of the PGC-1α transcription cascade of OXPHOS complexes in serum-starved fibroblast cultures. The positive effect of HT was associated with activation of PKA and CREB phosphorylation. These results show involvement of PKA, CREB and PGC-1α in the regulation of OXPHOS in cell transition from the replicating to the quiescent state.


Subject(s)
Cyclic AMP-Dependent Protein Kinases/biosynthesis , Mitochondria/enzymology , Oxidative Phosphorylation/drug effects , Peroxisome Proliferator-Activated Receptors/metabolism , ATP Synthetase Complexes/genetics , Adenosine Triphosphate/metabolism , Cyclic AMP Response Element-Binding Protein/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Electron Transport Complex I/genetics , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , Hydrogen Peroxide/metabolism , Mitochondria/metabolism , Nuclear Respiratory Factor 1/metabolism , Phenylethyl Alcohol/analogs & derivatives , Phenylethyl Alcohol/pharmacology , Signal Transduction/drug effects
12.
Am J Physiol Gastrointest Liver Physiol ; 309(10): G826-40, 2015 Nov 15.
Article in English | MEDLINE | ID: mdl-26336926

ABSTRACT

The p66Shc protein mediates oxidative stress-related injury in multiple tissues. Steatohepatitis is characterized by enhanced oxidative stress-mediated cell damage. The role of p66Shc in redox signaling was investigated in human liver cells and alcoholic steatohepatitis. HepG2 cells with overexpression of wild-type or mutant p66Shc, with Ser36 replacement by Ala, were obtained through infection with recombinant adenoviruses. Reactive oxygen species and oxidation-dependent DNA damage were assessed by measuring dihydroethidium oxidation and 8-hydroxy-2'-deoxyguanosine accumulation into DNA, respectively. mRNA and protein levels of signaling intermediates were evaluated in HepG2 cells and liver biopsies from control and alcoholic steatohepatitis subjects. Exposure to H2O2 increased reactive oxygen species and phosphorylation of p66Shc on Ser36 in HepG2 cells. Overexpression of p66Shc promoted reactive oxygen species synthesis and oxidation-dependent DNA damage, which were further enhanced by H2O2. p66Shc activation also resulted in increased Erk-1/2, Akt, and FoxO3a phosphorylation. Blocking of Erk-1/2 activation inhibited p66Shc phosphorylation on Ser36. Increased p66Shc expression was associated with reduced mRNA levels of antioxidant molecules, such as NF-E2-related factor 2 and its target genes. In contrast, overexpression of the phosphorylation defective p66Shc Ala36 mutant inhibited p66Shc signaling, enhanced antioxidant genes, and suppressed reactive oxygen species and oxidation-dependent DNA damage. Increased p66Shc protein levels and Akt phosphorylation were observed in liver biopsies from alcoholic steatohepatitis compared with control subjects. In human alcoholic steatohepatitis, increased hepatocyte p66Shc protein levels may enhance susceptibility to DNA damage by oxidative stress by promoting reactive oxygen species synthesis and repressing antioxidant pathways.


Subject(s)
DNA Damage , Fatty Liver, Alcoholic/metabolism , Hepatocytes/metabolism , Oxidation-Reduction , Oxidative Stress , Shc Signaling Adaptor Proteins , Cell Culture Techniques , Forkhead Box Protein O3 , Forkhead Transcription Factors/metabolism , Humans , Oncogene Protein v-akt/metabolism , Phosphorylation , Reactive Oxygen Species/metabolism , Shc Signaling Adaptor Proteins/genetics , Shc Signaling Adaptor Proteins/metabolism , Signal Transduction , Src Homology 2 Domain-Containing, Transforming Protein 1
13.
Curr Diab Rep ; 15(3): 12, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25687500

ABSTRACT

Lipodystrophies are a genetically heterogeneous group of disorders characterized by loss of subcutaneous adipose tissue and metabolic dysfunction, including insulin resistance, increased levels of free fatty acids, abnormal adipocytokine secretion, and ectopic fat deposition, which are also observed in patients with visceral obesity and/or type 2 diabetes mellitus. Pathophysiological, biochemical, and genetic studies suggest that impairment in multiple adipose tissue functions, including adipocyte maturation, lipid storage, formation and/or maintenance of the lipid droplet, membrane composition, DNA repair efficiency, and insulin signaling, results in severe metabolic and endocrine consequences, ultimately leading to specific lipodystrophic phenotypes. In this review, recent evidences on the causes and metabolic processes of lipodystrophies will be presented, proposing a disease model that could be potentially informative for better understanding of common metabolic diseases in humans, including obesity, metabolic syndrome, and type 2 diabetes.


Subject(s)
Diabetes Mellitus, Type 2/complications , Lipodystrophy/complications , Adipose Tissue/pathology , Genetic Association Studies , Humans , Lipodystrophy/classification , Lipodystrophy/drug therapy , Lipodystrophy/genetics , Mitochondria/metabolism
14.
Nat Genet ; 37(11): 1258-63, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16227998

ABSTRACT

We identified 11 human pedigrees with dominantly inherited hemolytic anemias in both the hereditary stomatocytosis and spherocytosis classes. Affected individuals in these families had an increase in membrane permeability to Na and K that is particularly marked at 0 degrees C. We found that disease in these pedigrees was associated with a series of single amino-acid substitutions in the intramembrane domain of the erythrocyte band 3 anion exchanger, AE1. Anion movements were reduced in the abnormal red cells. The 'leak' cation fluxes were inhibited by SITS, dipyridamole and NS1652, chemically diverse inhibitors of band 3. Expression of the mutated genes in Xenopus laevis oocytes induced abnormal Na and K fluxes in the oocytes, and the induced Cl transport was low. These data are consistent with the suggestion that the substitutions convert the protein from an anion exchanger into an unregulated cation channel.


Subject(s)
Anion Exchange Protein 1, Erythrocyte/genetics , Cations/metabolism , Chlorides/metabolism , Erythrocytes/metabolism , Potassium/metabolism , Sodium/metabolism , 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid/pharmacology , Amino Acid Substitution , Anemia, Hemolytic/genetics , Anemia, Hemolytic/metabolism , Animals , Anion Exchange Protein 1, Erythrocyte/metabolism , Benzoates/pharmacology , Biological Transport , Cell Membrane Permeability , Dipyridamole/pharmacology , Humans , Molecular Sequence Data , Oocytes/cytology , Oocytes/metabolism , Pedigree , Phenylurea Compounds/pharmacology , Phosphodiesterase Inhibitors/pharmacology , Protein Structure, Tertiary , RNA/metabolism , Spherocytosis, Hereditary/genetics , Xenopus laevis
15.
Genes (Basel) ; 14(12)2023 12 10.
Article in English | MEDLINE | ID: mdl-38137016

ABSTRACT

Large-scale genomic structural variations can have significant clinical implications, depending on the specific altered genomic region. Briefly, 2q37 microdeletion syndrome is a prevalent subtelomeric deletion disorder characterized by variable-sized deletions. Affected patients exhibit a wide range of clinical manifestations, including short stature, facial dysmorphism, and features of autism spectrum disorder, among others. Conversely, isolated duplications of proximal chromosome 2q are rare and lack a distinct phenotype. In this report, we provide an extensive molecular analysis of a 15-day-old newborn referred for syndromic features. Our analysis reveals an 8.5 Mb microdeletion at 2q37.1, which extends to the telomere, in conjunction with an 8.6 Mb interstitial microduplication at 2q34q36.1. Our findings underscore the prominence of 2q37 terminal deletions as commonly reported genomic anomalies. We compare our patient's phenotype with previously reported cases in the literature to contribute to a more refined classification of 2q37 microdeletion syndrome and assess the potential impact of 2q34q36.1 microduplication. We also investigate multiple hypotheses to clarify the genetic mechanisms responsible for the observed genomic rearrangement.


Subject(s)
Autism Spectrum Disorder , Intellectual Disability , Infant, Newborn , Humans , Chromosome Deletion , Intellectual Disability/genetics , Autism Spectrum Disorder/genetics , Chromosome Structures , Telomere
16.
Nat Commun ; 14(1): 1475, 2023 03 17.
Article in English | MEDLINE | ID: mdl-36928426

ABSTRACT

Split-Hand/Foot Malformation type 3 (SHFM3) is a congenital limb malformation associated with tandem duplications at the LBX1/FGF8 locus. Yet, the disease patho-mechanism remains unsolved. Here we investigate the functional consequences of SHFM3-associated rearrangements on chromatin conformation and gene expression in vivo in transgenic mice. We show that the Lbx1/Fgf8 locus consists of two separate, but interacting, regulatory domains. Re-engineering of a SHFM3-associated duplication and a newly reported inversion in mice results in restructuring of the chromatin architecture. This leads to ectopic activation of the Lbx1 and Btrc genes in the apical ectodermal ridge (AER) in an Fgf8-like pattern induced by AER-specific enhancers of Fgf8. We provide evidence that the SHFM3 phenotype is the result of a combinatorial effect on gene misexpression in the developing limb. Our results reveal insights into the molecular mechanism underlying SHFM3 and provide conceptual framework for how genomic rearrangements can cause gene misexpression and disease.


Subject(s)
Fibroblast Growth Factor 8 , Gene Rearrangement , Limb Deformities, Congenital , Animals , Mice , Gene Expression , Homeodomain Proteins/genetics , Limb Deformities, Congenital/genetics , Phenotype , Regulatory Sequences, Nucleic Acid , Transcription Factors/genetics
17.
Expert Rev Mol Med ; 14: e19, 2012 Dec 10.
Article in English | MEDLINE | ID: mdl-23302474

ABSTRACT

Stem cells are unique cells exhibiting self-renewing properties and the potential to differentiate into multiple specialised cell types. Totipotent or pluripotent stem cells are generally abundant in embryonic or fetal tissues, but the use of discarded embryos as sources of these cells raises challenging ethical problems. Adult stem cells can also differentiate into a wide variety of cell types. In particular, adult adipose tissue contains a pool of abundant and accessible multipotent stem cells, designated as adipose-derived stem cells (ASCs), that are able to replicate as undifferentiated cells, to develop as mature adipocytes and to differentiate into multiple other cell types along the mesenchymal lineage, including chondrocytes, myocytes and osteocytes, and also into cells of endodermal and neuroectodermal origin, including beta-cells and neurons, respectively. An impairment in the differentiation potential and biological functions of ASCs may contribute to the development of obesity and related comorbidities. In this review, we summarise different aspects of the ASCs with special reference to the isolation and characterisation of these cell populations, their relation to the biochemical features of the adipose tissue depot of origin and to the metabolic characteristics of the donor subject and discuss some prospective therapeutic applications.


Subject(s)
Adipocytes/cytology , Adipose Tissue/cytology , Metabolic Diseases/etiology , Obesity/etiology , Stem Cells/cytology , Adipocytes/metabolism , Cell Differentiation , Humans , Metabolic Diseases/therapy , Obesity/therapy , Stem Cell Transplantation , Stem Cells/metabolism
18.
Brain Sci ; 12(5)2022 May 08.
Article in English | MEDLINE | ID: mdl-35625000

ABSTRACT

Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare congenital disease characterized by the absence of horizontal gaze movements, progressive scoliosis, and typical brain, cerebellum, and medullary malformations. Here we describe a pediatric HGPPS case with overlapping epilepsy and learning difficulties. A 6-year-old girl was admitted to the University Hospital of Bari for the onset of a tonic-clonic seizure. Electroencephalogram showed slow and sharp waves on the right side with the tendency to diffuse. Brain magnetic resonance imaging demonstrated malformations compatible with HGPPS. Ophthalmological and orthopedic evaluations confirmed conjugate horizontal gaze palsy and mild thoracolumbar scoliosis. Neuropsychological assessment attested normal intelligence but serious difficulties in reading and writing. In spite of neuroradiological malformations, visual difficulties, and spinal deformities, literature data are limited about any coexisting neurocognitive HGPPS symptoms. Literature data regarding such topics are very limited. If, on the one hand, the coexistence of such symptoms can be interpreted as occasional, it could support the idea that they could fall within a spectrum of HGPPS anomalies. In addition to the standard investigations, the activation of specific neuropsychological assessment programs could help interventions improve the specialist care and the quality of life of HGPPS patients.

19.
Front Oncol ; 12: 966063, 2022.
Article in English | MEDLINE | ID: mdl-35992853

ABSTRACT

BRCA-1 associated protein 1 (BAP1) tumour predisposition syndrome (TPDS) is a hereditary condition characterised by germline mutation of the tumour suppressor BAP1. This disorder is associated with the development of various benign and malignant tumours, mainly involving the skin, eyes, kidneys, and mesothelium. In this article, we report the case of a man recruited through the Apulia (Southern Italy) Mesothelioma Regional Operational Centre of the National Register of Mesotheliomas, who suffered from uveal melanoma, renal cancer, and mesothelioma, and a familial cluster of BAP1 germline mutations demonstrated by molecular analyses. The family members of the proband developed multiple malignancies. As tumours arising in this context have specific peculiarities in terms of clinical behaviour, identification of this condition through appropriate genetic counselling should be considered for adequate primary, secondary, and tertiary prevention measures for offspring.

20.
Genes (Basel) ; 12(6)2021 06 07.
Article in English | MEDLINE | ID: mdl-34200357

ABSTRACT

Chromosome deletions, including band 5q12, have rarely been reported and have been associated with a wide range of clinical manifestations, such as postnatal growth retardation, intellectual disability, hyperactivity, nonspecific ocular defects, facial dysmorphism, and epilepsy. In this study, we describe for the first time a child with growth retardation in which we identified a balanced t(3;10) translocation by conventional cytogenetic analysis in addition to an 8.6 Mb 5q12 deletion through array-CGH. Our results show that the phenotypic abnormalities of a case that had been interpreted as "balanced" by conventional cytogenetics are mainly due to a cryptic deletion, highlighting the need for molecular investigation in subjects with an abnormal phenotype before assuming the cause is an apparently simple cytogenetic rearrangement. Finally, we identify PDE4D and PIK3R1 genes as the two major candidates responsible for the clinical features expressed in our patient.


Subject(s)
Chromosome Deletion , Chromosome Disorders/genetics , Chromosomes, Human, Pair 5/genetics , Growth Disorders/genetics , Chromosome Disorders/pathology , Class Ia Phosphatidylinositol 3-Kinase/genetics , Comparative Genomic Hybridization , Cyclic Nucleotide Phosphodiesterases, Type 4/genetics , Female , Growth Disorders/pathology , Humans , Infant , Karyotyping , Phenotype , Translocation, Genetic
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