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1.
Am J Med Genet B Neuropsychiatr Genet ; 195(2): e32956, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37584268

ABSTRACT

Smith-Magenis syndrome (SMS) is a neurodevelopmental disorder caused by a 17p11.2 deletion or a pathogenic variant of the RAI1 gene, which lies within the 17p11.2 region. Various psychiatric and neurological disorders have been reported in SMS, with most literature focusing on children and adolescents. To provide an overview of the current knowledge on this topic in adults with SMS, we performed a comprehensive scoping review of the relevant literature. Our findings suggest that many manifestations that are common in childhood persist into adulthood. Neuropsychiatric manifestations in adults with SMS include intellectual disability, autism spectrum- and attention deficit hyperactivity disorder-related features, self-injurious and physical aggressive behaviors, sleep-wake disorders, and seizures. Findings of this review may facilitate optimization of management strategies in adults with SMS, and may guide future studies exploring late-onset psychiatric and neurological comorbidities in SMS.


Subject(s)
Intellectual Disability , Neurodevelopmental Disorders , Smith-Magenis Syndrome , Adult , Child , Adolescent , Humans , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Trans-Activators , Intellectual Disability/genetics , Neurodevelopmental Disorders/genetics , Aggression
2.
Cell Death Dis ; 13(11): 981, 2022 11 21.
Article in English | MEDLINE | ID: mdl-36411275

ABSTRACT

Smith-Magenis syndrome (SMS) is a neurodevelopmental disorder characterized by cognitive and behavioral symptoms, obesity, and sleep disturbance, and no therapy has been developed to alleviate its symptoms or delay disease onset. SMS occurs due to haploinsufficiency of the retinoic acid-induced-1 (RAI1) gene caused by either chromosomal deletion (SMS-del) or RAI1 missense/nonsense mutation. The molecular mechanisms underlying SMS are unknown. Here, we generated and characterized primary cells derived from four SMS patients (two with SMS-del and two carrying RAI1 point mutations) and four control subjects to investigate the pathogenetic processes underlying SMS. By combining transcriptomic and lipidomic analyses, we found altered expression of lipid and lysosomal genes, deregulation of lipid metabolism, accumulation of lipid droplets, and blocked autophagic flux. We also found that SMS cells exhibited increased cell death associated with the mitochondrial pathology and the production of reactive oxygen species. Treatment with N-acetylcysteine reduced cell death and lipid accumulation, which suggests a causative link between metabolic dyshomeostasis and cell viability. Our results highlight the pathological processes in human SMS cells involving lipid metabolism, autophagy defects and mitochondrial dysfunction and suggest new potential therapeutic targets for patient treatment.


Subject(s)
Smith-Magenis Syndrome , Humans , Smith-Magenis Syndrome/diagnosis , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Haploinsufficiency/genetics , Lipid Metabolism/genetics , Transcription Factors/metabolism , Trans-Activators/metabolism , Phenotype , Autophagy/genetics , Tretinoin/pharmacology , Tretinoin/metabolism , Lipids
6.
Dtsch Med Wochenschr ; 145(16): 1139-1144, 2020 08.
Article in German | MEDLINE | ID: mdl-32791549

ABSTRACT

Two major advances were made in the treatment of chronic lymphocytic leukaemia (CLL): the addition of the antibody rituximab to chemotherapy two decades ago and the introduction of the targeted agents during the last few years. Four targeted drugs with different mechanisms of action were added to the armamentarium of CLL treatment: the anti-CD20 antibody obinutuzumab, the two kinase inhibitors ibrutinib and idelalisib, which target the Bruton tyrosine kinase (BTK) and Phosphatidylinositiol-3-Kinase (PI3K) respectively in the B-cell receptor signalling pathway, as well as the Bcl2-antagonist venetoclax.Recently, the combination of venetoclax/obinutuzumab was approved for the first-line treatment of all CLL patients based on a phase-III trial in elderly unfit patients. This combination was shown to be clearly superior to chlorambucil/obinutuzumab and should become the preferred first-line treatment for the so called "slow-go" patients. Other options for these elderly, unfit patients are continuous ibrutinib or chlorambucil/obinutuzumab. Although data from phase-III studies are not yet available, venetoclax/obintuzumab may also be offered to younger, fit patients. Established therapeutic options for these so called "go go" patients are ibrutinib, fludarabin/cyclophosphamide/rituximab or bendemustine/rituximab (if > 65 years). Patients with the high-risk parameters deletion 17p or TP53mutation are known to poorly respond to chemo(immuno)therapy and should receive either ibrutinib or venetoclax/obinutuzumab.Thus, a choice has to be made between a continuous monotherapy with ibrutinib or a time-limited combination with either venetoclax/obinutuzumab (12 months) or chemoimmunotherapy (usually 6 months). In addition to disease-related factors (e. g. presence of deletion 17p/TP53 mutation, IgHV mutational status, prior therapies), comorbidities, co-medication and the specific side effects of the CLL therapies (myelosuppression, infections and secondary malignancies for chemoimmunotherapy; cardiac toxicity, bleeding and autoimmune disease for ibrutinib; tumour-lysis syndromes and infections for venetoclax) the patient's expectations need to be considered.


Subject(s)
Antineoplastic Agents/therapeutic use , Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Adenine/adverse effects , Adenine/analogs & derivatives , Adenine/therapeutic use , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Agents/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bridged Bicyclo Compounds, Heterocyclic/adverse effects , Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , Chromosome Deletion , Chromosomes, Human, Pair 17/genetics , Clinical Trials, Phase III as Topic , Combined Modality Therapy , Comorbidity , Drug Approval , Humans , Immunotherapy , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Neoplasm Staging , Piperidines/adverse effects , Piperidines/therapeutic use , Prognosis , Purines/adverse effects , Purines/therapeutic use , Quinazolinones/adverse effects , Quinazolinones/therapeutic use , Rituximab/adverse effects , Rituximab/therapeutic use , Smith-Magenis Syndrome/diagnosis , Smith-Magenis Syndrome/drug therapy , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Sulfonamides/adverse effects , Sulfonamides/therapeutic use
7.
Am J Med Genet A ; 182(9): 2077-2084, 2020 09.
Article in English | MEDLINE | ID: mdl-32656927

ABSTRACT

Potocki-Lupski Syndrome (PTLS, MIM 610883), or duplication of chromosome 17p11.2, is a clinically recognizable condition characterized by infantile hypotonia, failure to thrive, developmental delay, intellectual disability, and congenital anomalies. Short stature, classified as greater than two standard deviations below the mean, has not previously been considered a major feature of PTLS. Retrospective chart review on a cohort of 37 individuals with PTLS was performed to investigate the etiology of short stature. Relevant data included anthropometric measurements, insulin growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), growth hormone (GH) stimulation testing, blood glucose levels, brain MRI, and bone age. Approximately 25% (9/37) of individuals with PTLS had short stature. Growth hormone deficiency (GHD) was definitively identified in two individuals. These two PTLS patients with growth hormone deficiency, as well as three others with short stature and no documented GHD, received growth hormone and obtained improvement in linear growth. One individual was identified to have pituitary abnormalities on MRI and had complications of hypoglycemia due to unrecognized GHD. Individuals with PTLS can benefit from undergoing evaluation for GHD should they present with short stature or hypoglycemia. Early identification of GHD could facilitate potential therapeutic benefit for individuals with PTLS, including linear growth, musculoskeletal, and in cases of hypoglycemia, potentially cognitive development as well.


Subject(s)
Abnormalities, Multiple/genetics , Chromosome Disorders/genetics , Chromosome Duplication/genetics , Dwarfism, Pituitary/genetics , Insulin-Like Growth Factor Binding Protein 3/genetics , Insulin-Like Growth Factor I/genetics , Abnormalities, Multiple/diagnostic imaging , Abnormalities, Multiple/epidemiology , Abnormalities, Multiple/pathology , Adolescent , Adult , Blood Glucose/genetics , Brain/diagnostic imaging , Brain/pathology , Child , Child, Preschool , Chromosome Disorders/diagnostic imaging , Chromosome Disorders/epidemiology , Chromosome Disorders/pathology , Comparative Genomic Hybridization , Dwarfism, Pituitary/diagnostic imaging , Dwarfism, Pituitary/epidemiology , Dwarfism, Pituitary/pathology , Failure to Thrive/epidemiology , Failure to Thrive/genetics , Failure to Thrive/pathology , Female , Human Growth Hormone/deficiency , Human Growth Hormone/genetics , Humans , Infant , Magnetic Resonance Imaging , Male , Phenotype , Smith-Magenis Syndrome/diagnostic imaging , Smith-Magenis Syndrome/epidemiology , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Young Adult
8.
Diagn Cytopathol ; 47(9): 930-934, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31120625

ABSTRACT

Primary thyroid teratomas are rare, usually benign, and typically occur in children. We report the unusual occurrence of a malignant thyroid teratoma in a young man. Initial ultrasound and CT studies revealed an 8.5 heterogeneous mass involving the entire right thyroid lobe causing tracheal compression and deviation. Fine-needle aspiration (FNA) revealed malignant cells with possible neuroendocrine features. Similar findings have been previously reported, with an occasional interpretation as possible medullary thyroid carcinoma. In no report, as with our case, has the correct diagnosis been suggested with FNA. The surgical specimen contained abundant primitive neuroepithelium with a very minor component of mature ectodermal tissue in one area. Like this case, an abundance of immature neuroepithelium has been reported in essentially all previous reports of primary malignant thyroid teratoma, sometimes creating a challenge to find another type of germ cell tissue. Array comparative genomic hybridization studies in this case revealed a markedly complex karyotype including gain of chromosome 12 and loss of 17p. Amplification of MYCN, EWSR1 rearrangement and isochromosome 12p were not identified, providing no evidence for neuroblastoma or Ewing sarcoma/peripheral neuroectodermal tumor, both of which have also rarely been reported as primary thyroid tumors. With the use of cisplatinum-based chemotherapy combined with radiation, survival times have increased dramatically. Our patient is now disease free and back to his normal activities after relatively short follow-up. Although rare, it is important to be aware that teratomas may present as a thyroid nodule. Recognition by FNA is challenging, and requires multiple modalities for full identification.


Subject(s)
Chemoradiotherapy , Cisplatin/administration & dosage , Teratoma , Thyroid Neoplasms , Adolescent , Biopsy, Fine-Needle , Chromosome Deletion , Chromosomes, Human, Pair 12/genetics , Chromosomes, Human, Pair 12/metabolism , Chromosomes, Human, Pair 17/genetics , Chromosomes, Human, Pair 17/metabolism , Humans , Male , N-Myc Proto-Oncogene Protein/genetics , N-Myc Proto-Oncogene Protein/metabolism , RNA-Binding Protein EWS/genetics , RNA-Binding Protein EWS/metabolism , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/metabolism , Smith-Magenis Syndrome/pathology , Smith-Magenis Syndrome/therapy , Teratoma/genetics , Teratoma/metabolism , Teratoma/pathology , Teratoma/therapy , Thyroid Neoplasms/genetics , Thyroid Neoplasms/metabolism , Thyroid Neoplasms/pathology , Thyroid Neoplasms/therapy
9.
Genome Med ; 11(1): 12, 2019 02 28.
Article in English | MEDLINE | ID: mdl-30819258

ABSTRACT

BACKGROUND: Neurodevelopmental disorders are genetically and phenotypically heterogeneous encompassing developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), structural brain abnormalities, and neurological manifestations with variants in a large number of genes (hundreds) associated. To date, a few de novo mutations potentially disrupting TCF20 function in patients with ID, ASD, and hypotonia have been reported. TCF20 encodes a transcriptional co-regulator structurally related to RAI1, the dosage-sensitive gene responsible for Smith-Magenis syndrome (deletion/haploinsufficiency) and Potocki-Lupski syndrome (duplication/triplosensitivity). METHODS: Genome-wide analyses by exome sequencing (ES) and chromosomal microarray analysis (CMA) identified individuals with heterozygous, likely damaging, loss-of-function alleles in TCF20. We implemented further molecular and clinical analyses to determine the inheritance of the pathogenic variant alleles and studied the spectrum of phenotypes. RESULTS: We report 25 unique inactivating single nucleotide variants/indels (1 missense, 1 canonical splice-site variant, 18 frameshift, and 5 nonsense) and 4 deletions of TCF20. The pathogenic variants were detected in 32 patients and 4 affected parents from 31 unrelated families. Among cases with available parental samples, the variants were de novo in 20 instances and inherited from 4 symptomatic parents in 5, including in one set of monozygotic twins. Two pathogenic loss-of-function variants were recurrent in unrelated families. Patients presented with a phenotype characterized by developmental delay, intellectual disability, hypotonia, variable dysmorphic features, movement disorders, and sleep disturbances. CONCLUSIONS: TCF20 pathogenic variants are associated with a novel syndrome manifesting clinical characteristics similar to those observed in Smith-Magenis syndrome. Together with previously described cases, the clinical entity of TCF20-associated neurodevelopmental disorders (TAND) emerges from a genotype-driven perspective.


Subject(s)
Craniofacial Abnormalities/genetics , Developmental Disabilities/genetics , INDEL Mutation , Intellectual Disability/genetics , Muscle Hypotonia/genetics , Smith-Magenis Syndrome/genetics , Transcription Factors/genetics , Adolescent , Child , Child, Preschool , Craniofacial Abnormalities/pathology , Developmental Disabilities/pathology , Female , Humans , Infant , Intellectual Disability/pathology , Male , Muscle Hypotonia/pathology , Smith-Magenis Syndrome/pathology , Transcription Factors/metabolism , Young Adult
10.
Proc Natl Acad Sci U S A ; 115(42): 10744-10749, 2018 10 16.
Article in English | MEDLINE | ID: mdl-30275311

ABSTRACT

Haploinsufficiency of Retinoic Acid Induced 1 (RAI1) causes Smith-Magenis syndrome (SMS), a syndromic autism spectrum disorder associated with craniofacial abnormalities, intellectual disability, and behavioral problems. There is currently no cure for SMS. Here, we generated a genetic mouse model to determine the reversibility of SMS-like neurobehavioral phenotypes in Rai1 heterozygous mice. We show that normalizing the Rai1 level 3-4 wk after birth corrected the expression of genes related to neural developmental pathways and fully reversed a social interaction deficit caused by Rai1 haploinsufficiency. In contrast, Rai1 reactivation 7-8 wk after birth was not beneficial. We also demonstrated that the correct Rai1 dose is required in both excitatory and inhibitory neurons for proper social interactions. Finally, we found that Rai1 heterozygous mice exhibited a reduction of dendritic spines in the medial prefrontal cortex (mPFC) and that optogenetic activation of mPFC neurons in adults improved the social interaction deficit of Rai1 heterozygous mice. Together, these results suggest the existence of a postnatal temporal window during which restoring Rai1 can improve the transcriptional and social behavioral deficits in a mouse model of SMS. It is possible that circuit-level interventions would be beneficial beyond this critical window.


Subject(s)
Disease Models, Animal , Haploinsufficiency , Interpersonal Relations , Smith-Magenis Syndrome/genetics , Social Behavior Disorders/prevention & control , Trans-Activators/pharmacology , Adolescent , Animals , Dendritic Spines/metabolism , Dendritic Spines/pathology , Heterozygote , Humans , Male , Mice , Mutation , Phenotype , Smith-Magenis Syndrome/pathology , Social Behavior Disorders/genetics
11.
Clin Cancer Res ; 24(18): 4371-4379, 2018 09 15.
Article in English | MEDLINE | ID: mdl-29895707

ABSTRACT

Purpose: The oral BCL-2 inhibitor venetoclax is an effective therapy for patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL), including disease with high-risk genomic features such as chromosome 17p deletion [del(17p)] or progressive disease following B-cell receptor pathway inhibitors.Patients and Methods: We conducted a comprehensive analysis of the safety of 400 mg daily venetoclax monotherapy in 350 patients with CLL using an integrated dataset from three phase I/II studies.Results: Median age was 66 years and 60% had del(17p). Patients had received a median of three prior therapies (range: 0-15); 42% previously received ibrutinib or idelalisib. Median duration of exposure to venetoclax was 16 months (0-56). In the pooled analysis, the most common adverse events (AE) of any grade were diarrhea (41%), neutropenia (40%), nausea (39%), anemia (31%), fatigue (28%), and upper respiratory tract infection (25%). The most common grade 3/4 AEs were neutropenia (37%), anemia (17%), and thrombocytopenia (14%). With the current 5-week ramp-up dosing, the incidence of laboratory TLS was 1.4% (2/166), none had clinical sequelae, and all of these patients were able to ramp-up to a daily dose of 400 mg. Grade 3/4 neutropenia was manageable with growth factor support and dose adjustments; the incidence of serious infections in these patients was 15%. Ten percent of patients discontinued venetoclax due to AEs and 8% died while on study, with the majority of deaths in the setting of disease progression.Conclusions: Venetoclax as a long-term continuous therapy is generally well tolerated in patients with R/R CLL when initiated with the current treatment algorithm. Clin Cancer Res; 24(18); 4371-9. ©2018 AACR.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , Drug-Related Side Effects and Adverse Reactions/classification , Gastrointestinal Tract/drug effects , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Sulfonamides/therapeutic use , Adult , Aged , Aged, 80 and over , Bridged Bicyclo Compounds, Heterocyclic/administration & dosage , Bridged Bicyclo Compounds, Heterocyclic/adverse effects , Chromosome Deletion , Chromosomes, Human, Pair 17/genetics , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Gastrointestinal Tract/pathology , Gene Expression Regulation, Neoplastic/drug effects , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Male , Middle Aged , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/genetics , Smith-Magenis Syndrome/drug therapy , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Sulfonamides/administration & dosage , Sulfonamides/adverse effects , Treatment Outcome , Tumor Suppressor Protein p53/genetics
12.
J Clin Oncol ; 36(19): 1973-1980, 2018 07 01.
Article in English | MEDLINE | ID: mdl-29715056

ABSTRACT

Purpose Venetoclax is an orally bioavailable B-cell lymphoma 2 inhibitor. US Food and Drug Administration and European Medicines Agency approval for patients with 17p deleted relapsed/refractory chronic lymphocytic leukemia [del(17p) CLL] was based on results from 107 patients. An additional 51 patients were enrolled in a safety expansion cohort. Extended analysis of all enrolled patients, including the effect of minimal residual disease (MRD) negativity on outcome, is now reported. Patients and Methods Overall, 158 patients with relapsed/refractory or previously untreated (n = 5) del(17p) CLL received venetoclax 400 mg per day after an initial dose ramp up. Responses were based on 2008 International Workshop on Chronic Lymphocytic Leukemia criteria, with monthly physical exams and blood counts. Computed tomography scan was mandatory at week 36, after which assessment made was by clinical evaluation. Marrow biopsy was performed when complete remission was suspected. MRD was assessed by flow cytometry. Results Patients had a median of two prior therapies (range, zero to 10 therapies), 71% had TP53 mutation, and 48% had nodes that were ≥ 5 cm. Median time on venetoclax was 23.1 months (range, 0 to 44.2 months) and median time on study was 26.6 months (range, 0 to 44.2 months). For all patients, investigator-assessed objective response rate was 77% (122 of 158 patients; 20% complete remission) and estimated progression-free survival at 24 months was 54% (95% CI, 45% to 62%). For 16 patients who received prior kinase inhibitors, objective response rate was 63% (10 of 16 patients) and 24-month progression-free survival estimate was 50% (95% CI, 25% to 71%). By intent-to-treat analysis, 48 (30%) of 158 patients achieved MRD below the cutoff of 10-4 in blood. Common grade 3 and 4 adverse events were hematologic and managed with supportive care and/or dose adjustments. Conclusion Venetoclax achieves durable responses and was well tolerated in patients with del(17p) CLL. A high rate of blood MRD < 10-4 was achieved in this high-risk population.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/administration & dosage , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Smith-Magenis Syndrome/pathology , Sulfonamides/administration & dosage , Administration, Oral , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacokinetics , Bridged Bicyclo Compounds, Heterocyclic/adverse effects , Bridged Bicyclo Compounds, Heterocyclic/pharmacokinetics , Chromosome Deletion , Chromosomes, Human, Pair 17/genetics , Female , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Male , Middle Aged , Neoplasm, Residual/pathology , Smith-Magenis Syndrome/genetics , Sulfonamides/adverse effects , Sulfonamides/pharmacokinetics
13.
J Hum Genet ; 63(7): 795-801, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29691480

ABSTRACT

Multiple genomic disorders result from recurrent deletions or duplications between low copy repeat (LCR) clusters, mediated by nonallelic homologous recombination. These copy number variants (CNVs) often exhibit variable expressivity and/or incomplete penetrance. However, the population prevalence of many genomic disorders has not been estimated accurately. A subset of genomic disorders similarly characterized by CNVs between LCRs have been studied epidemiologically, including Williams-Beuren syndrome (7q11.23), Smith-Magenis syndrome (17p11.2), velocardiofacial syndrome (22q11.21), Prader-Willi/Angelman syndromes (15q11.2q12), 17q12 deletion syndrome, and Charcot-Marie-Tooth neuropathy type 1/hereditary neuropathy with liability to pressure palsy (PMP22, 17q11.2). We have generated a method to estimate prevalence of highly penetrant genomic disorders by (1) leveraging epidemiological data for genomic disorders with previously reported prevalence estimates, (2) obtaining chromosomal microarray data on genomic disorders from a large medical genetics clinic; and (3) utilizing these in a linear regression model to determine the prevalence of this syndromic copy number change among the general population. Using our algorithm, the prevalence for five clinically relevant recurrent genomic disorders: 1q21.1 microdeletion (1/6882 live births) and microduplication syndromes (1/6309), 15q13.3 microdeletion syndrome (1/5525), and 16p11.2 microdeletion (1/3021) and microduplication syndromes (1/4216), were determined. These findings will inform epidemiological strategies for evaluating those conditions, and our method may be useful to evaluate the prevalence of other highly penetrant genomic disorders.


Subject(s)
Charcot-Marie-Tooth Disease/epidemiology , DiGeorge Syndrome/epidemiology , Genome, Human , Models, Genetic , Prader-Willi Syndrome/epidemiology , Smith-Magenis Syndrome/epidemiology , Williams Syndrome/epidemiology , Charcot-Marie-Tooth Disease/genetics , Charcot-Marie-Tooth Disease/pathology , Chromosome Deletion , Chromosome Duplication , Chromosome Mapping , DNA Copy Number Variations , DiGeorge Syndrome/genetics , DiGeorge Syndrome/pathology , Humans , Microarray Analysis , Molecular Epidemiology , Penetrance , Prader-Willi Syndrome/genetics , Prader-Willi Syndrome/pathology , Prevalence , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Williams Syndrome/genetics , Williams Syndrome/pathology
14.
Eur J Med Genet ; 59(10): 499-501, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27633572

ABSTRACT

Smith-Magenis syndrome (SMS) is a contiguous-gene disorder most commonly caused by a deletion of chromosome 17p11.2. We report a 57 year-old man with SMS who presents bilateral renal tumors. This is most likely related to haploinsufficiency of FLCN gene, located in the deleted region, and a known tumor suppressor gene. Haploinsufficiency of FLCN causes Birt-Hogg-Dubé syndrome (BHDS), characterized by pulmonary cysts, renal and skin tumors. The present observation suggests that the follow-up of patients with SMS should also focus on possible manifestations of BHDS.


Subject(s)
Kidney Neoplasms/genetics , Proto-Oncogene Proteins/genetics , Skin Neoplasms/genetics , Smith-Magenis Syndrome/genetics , Tumor Suppressor Proteins/genetics , Birt-Hogg-Dube Syndrome/complications , Birt-Hogg-Dube Syndrome/genetics , Birt-Hogg-Dube Syndrome/pathology , Exons/genetics , Genetic Predisposition to Disease , Haploinsufficiency/genetics , Humans , Kidney/pathology , Kidney Neoplasms/complications , Kidney Neoplasms/pathology , Male , Middle Aged , Mutation , Sequence Deletion , Skin Neoplasms/complications , Skin Neoplasms/pathology , Smith-Magenis Syndrome/pathology
15.
Sci Rep ; 6: 19010, 2016 Jan 08.
Article in English | MEDLINE | ID: mdl-26743651

ABSTRACT

RAI1 (retinoic acid induced-1) is a dosage-sensitive gene that causes Smith-Magenis syndrome (SMS) when mutated or deleted and Potocki-Lupski Syndrome (PTLS) when duplicated, with psychiatric features commonly observed in both syndromes. How common genetic variants regulate this gene, however, is unknown. In this study, we found that RAI1 mRNA expression in Chinese prefrontal and temporal cortex correlate with genotypes of common single nucleotide polymorphisms (SNPs) located in the RAI1 5'-upstream region. Using genotype imputation, "R(2)-Δ(2)" analysis, and data from the RegulomeDB database, we identified SNPs rs4925102 and rs9907986 as possible regulatory variants, accounting for approximately 30-40% of the variance in RAI1 mRNA expression in both brain regions. Specifically, rs4925102 and rs9907986 are predicted to disrupt the binding of retinoic acid RXR-RAR receptors and the transcription factor DEAF1 (Deformed epidermal autoregulatory factor-1), respectively. Consistent with these predictions, we observed binding of RXRα and RARα to the predicted RAI1 target in chromatin immunoprecipitation assays. Retinoic acid is crucial for early development of the central neural system, and DEAF1 is associated with intellectual disability. The observation that a significant portion of RAI1 mRNA expression is genetically controlled raises the possibility that common RAI1 5'-region regulatory variants contribute more generally to psychiatric disorders.


Subject(s)
Abnormalities, Multiple/genetics , Chromosome Disorders/genetics , Chromosome Duplication/genetics , Nuclear Proteins/genetics , RNA, Messenger/genetics , Retinoid X Receptors/genetics , Smith-Magenis Syndrome/genetics , Transcription Factors/genetics , Abnormalities, Multiple/metabolism , Abnormalities, Multiple/pathology , Base Sequence , Cell Line, Tumor , Chromosome Disorders/metabolism , Chromosome Disorders/pathology , DNA-Binding Proteins , Gene Dosage , Gene Expression Regulation , Genotype , Genotyping Techniques , Humans , Mutation , Neurons/metabolism , Neurons/pathology , Nuclear Proteins/metabolism , Phenotype , Polymorphism, Single Nucleotide , Prefrontal Cortex/metabolism , Prefrontal Cortex/pathology , RNA, Messenger/metabolism , Retinoid X Receptors/metabolism , Signal Transduction , Smith-Magenis Syndrome/metabolism , Smith-Magenis Syndrome/pathology , Temporal Lobe/metabolism , Temporal Lobe/pathology , Trans-Activators , Transcription Factors/metabolism
16.
Mol Med Rep ; 13(1): 347-52, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26572831

ABSTRACT

Smith­Magenis syndrome (SMS) is a rare condition with multiple congenital malformations caused by the haploinsufficiency of RAI1 (deletion or mutation of RAI1). However, the correlation between genotype and phenotype is not well understood. The present study describes the prenatal diagnosis of monozygotic twins with a 17p11.2 deletion, which is indicative of SMS, who presented with discordant phenotypes and uteroplacental insufficiency. A high­resolution genome­wide single nucleotide polymorphism array revealed a 3.7­Mb deletion in the 17p11.2 chromosome region. Accurate breakpoints of the deletion in these patients were used to identify correlations between SMS and the concomitant phenotypes, particularly uteroplacental insufficiency, which has rarely been investigated in SMS. In addition, no exonic mutations were identified in or affected known disease­associated loci that could explain the congenital anomalies, according to a model that accounts for the possibility of incomplete penetrance. Furthermore, a novel benign copy number variation (a duplication of 195 kb at 13q12.13) was identified but was unlikely to be clinically significant in the discordant phenotypes of the twins. The present study showed that multiple interacting genetic and environmental factors are involved in determining the variance of the SMS phenotype.


Subject(s)
Fetus/pathology , Placenta/pathology , Smith-Magenis Syndrome/pathology , Twins, Monozygotic , Uterus/pathology , Chromosomes, Human , DNA Copy Number Variations/genetics , Female , Humans , Phenotype , Pregnancy , Smith-Magenis Syndrome/diagnostic imaging , Ultrasonography, Prenatal , Young Adult
17.
Indian J Pediatr ; 83(6): 589-93, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26676648

ABSTRACT

Smith-Magenis syndrome is a well delineated microdeletion syndrome with characteristic facial and behavioral phenotype. With the availability of the multi-targeted molecular cytogenetic techniques like Multiplex Ligation Probe Amplification and cytogenetic microarray, the cases are diagnosed even without clinical suspicion. Here, the authors present clinical features of nine Indian cases of Smith-Magenis syndrome. Characteristic facial phenotype including tented upper lip, broad forehead, midface hypoplasia, short philtrum and upslant of palpebral fissure is obvious in the photographs. The behavioral variations were seen in some of the cases but were not the presenting features. The characteristic facial phenotype can be an important clinical guide to the diagnosis.


Subject(s)
Face/abnormalities , Smith-Magenis Syndrome/complications , Chromosome Deletion , Chromosomes, Human, Pair 17 , Humans , Intellectual Disability , Phenotype , Smith-Magenis Syndrome/pathology
18.
Int J Mol Sci ; 16(4): 7627-43, 2015 Apr 07.
Article in English | MEDLINE | ID: mdl-25853262

ABSTRACT

Roughly 20% of autism spectrum disorders (ASD) are syndromic with a well-established genetic cause. Studying the genes involved can provide insight into the molecular and cellular mechanisms of ASD. 2q23.1 deletion syndrome (causative gene, MBD5) is a recently identified genetic neurodevelopmental disorder associated with ASD. Mutations in MBD5 have been found in ASD cohorts. In this study, we provide a phenotypic update on the prevalent features of 2q23.1 deletion syndrome, which include severe intellectual disability, seizures, significant speech impairment, sleep disturbance, and autistic-like behavioral problems. Next, we examined the phenotypic, molecular, and network/pathway relationships between nine neurodevelopmental disorders associated with ASD: 2q23.1 deletion Rett, Angelman, Pitt-Hopkins, 2q23.1 duplication, 5q14.3 deletion, Kleefstra, Kabuki make-up, and Smith-Magenis syndromes. We show phenotypic overlaps consisting of intellectual disability, speech delay, seizures, sleep disturbance, hypotonia, and autistic-like behaviors. Molecularly, MBD5 possibly regulates the expression of UBE3A, TCF4, MEF2C, EHMT1 and RAI1. Network analysis reveals that there could be indirect protein interactions, further implicating function for these genes in common pathways. Further, we show that when MBD5 and RAI1 are haploinsufficient, they perturb several common pathways that are linked to neuronal and behavioral development. These findings support further investigations into the molecular and pathway relationships among genes linked to neurodevelopmental disorders and ASD, which will hopefully lead to common points of regulation that may be targeted toward therapeutic intervention.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 2/genetics , DNA-Binding Proteins/genetics , Neurodevelopmental Disorders/genetics , Neurodevelopmental Disorders/pathology , Transcription Factors/genetics , Adolescent , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/pathology , Cells, Cultured , Female , Gene Expression , Gene Regulatory Networks , Haploinsufficiency , Humans , Infant , Male , Signal Transduction , Smith-Magenis Syndrome/genetics , Smith-Magenis Syndrome/pathology , Trans-Activators
19.
Am J Med Genet A ; 164A(12): 3142-7, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25257626

ABSTRACT

Smith-Magenis syndrome (SMS) is caused by an interstitial microdeletion of chromosome 17p11.2. A few patients with the typical SMS phenotype have RAI1 gene mutations. The syndrome is characterized by minor craniofacial anomalies, short stature, sleep disturbances, behavioural and neurocognitive abnormalities, as well as variable multisystemic manifestations. Periventricular nodular heterotopia (PNH) is a genetically heterogeneous neuronal migration disorder characterized by subependymal heterotopic nodules, and is variably associated with other brain malformations, epileptic seizures and intellectual disability. Here we report on two patients harboring deletions of the 17p11.2 region in whom the SMS typical phenotype was associated with bilateral PNH. Our observations expand the spectrum of chromosomal rearrangements associated with PNH and indicate that abnormal neuronal migration may contribute to the neurocognitive phenotype of SMS.


Subject(s)
Periventricular Nodular Heterotopia/pathology , Smith-Magenis Syndrome/pathology , Adolescent , Brain/diagnostic imaging , Child, Preschool , Chromosome Deletion , Chromosomes, Human, Pair 17/genetics , Humans , Magnetic Resonance Imaging , Male , Radiography
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