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Öztürk Ö, Bagis H, Bolu S. Osteogenesis Imperfecta and Split Foot Malformation due to 7q21.2q21.3 Deletion Including COL1A2, DLX5/6 Genes: Review of the Literature. J Pediatr Genet 2024; 13:69-79. [PMID: 38567169 PMCID: PMC10984717 DOI: 10.1055/s-0041-1736613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 09/22/2021] [Indexed: 10/19/2022]
Abstract
Copy number variation in loss of 7q21 is a genetic disorder characterized by split hand/foot malformation, hearing loss, developmental delay, myoclonus, dystonia, joint laxity, and psychiatric disorders. Osteogenesis imperfecta caused by whole gene deletions of COL1A2 is a very rare condition. We report a Turkish girl with ectrodactyly, joint laxity, multiple bone fractures, blue sclera, early teeth decay, mild learning disability, and depression. A copy number variant in loss of 4.8 Mb at chromosome 7 (q21.2q21.3) included the 58 genes including DLX5, DLX6, DYNC1I1, SLC25A13, SGCE, and COL1A2 . They were identified by chromosomal microarray analysis. We compared the findings in our patients with those previously reported. This case report highlights the importance of using microarray to identify the genetic etiology in patients with ectrodactyly and osteogenesis imperfecta.
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Affiliation(s)
- Özden Öztürk
- Department of Medical Genetics, Medical School of Adiyaman University, Adiyaman, Türkiye
| | - Haydar Bagis
- Department of Medical Genetics, Medical School of Adiyaman University, Adiyaman, Türkiye
| | - Semih Bolu
- Department of Pediatrics, Division of Pediatric Endocrinology, Medical School of Adiyaman University, Adiyaman, Türkiye
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2
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Soliani L, Alcalá San Martín A, Balsells S, Hernando‐Davalillo C, Ortigoza‐Escobar JD. Chromosome Microarray Analysis for the Investigation of Deletions in Pediatric Movement Disorders: A Systematic Review of the Literature. Mov Disord Clin Pract 2023; 10:547-557. [PMID: 37070051 PMCID: PMC10105116 DOI: 10.1002/mdc3.13711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/19/2023] [Accepted: 02/19/2023] [Indexed: 03/06/2023] Open
Abstract
Background Chromosome microarray analysis (CMA) can detect copy number variants (CNV) beyond the resolution of standard G-banded karyotyping. De novo or inherited microdeletions may cause autosomal dominant movement disorders. Objectives The purpose of this study was to analyze the clinical characteristics, associated features, and genetic information of children with deletions in known genes that cause movement disorders and to make recommendations regarding the diagnostic application of CMA. Methods Clinical cases published in English were identified in scientific databases (PubMed, ClinVar, and DECIPHER) from January 1998 to July 2019 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Cases with deletions or microdeletions greater than 300 kb were selected. Information collected included age, sex, movement disorders, associated features, and the size and location of the deletion. Duplications or microduplications were not included. Results A total of 18.097 records were reviewed, and 171 individuals were identified. Ataxia (30.4%), stereotypies (23.9%), and dystonia (21%) were the most common movement disorders. A total of 16% of the patients demonstrated more than one movement disorder. The most common associated features were intellectual disability or developmental delay (78.9%) and facial dysmorphism (57.8%). The majority (77.7%) of microdeletions were smaller than 5 Mb. We find no correlation between movement disorders, their associated features, and the size of microdeletions. Conclusions Our results support the use of CMA as an investigational test in children with movement disorders. As the majority of identified articles were case reports and small case series (low quality), future efforts should focus on larger prospective studies to examine the causation of microdeletions in pediatric movement disorders.
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Affiliation(s)
- Luca Soliani
- IRCCS Istituto delle Scienze Neurologiche di Bologna UOC Neuropsichiatria dell'età PediatricaBolognaItaly
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC) Università di BolognaBolognaItaly
| | - Adrián Alcalá San Martín
- Department of Genetic and Molecular Medicine and Pediatric Institute of Rare DiseasesHospital Sant Joan de Déu BarcelonaBarcelonaSpain
| | - Sol Balsells
- Department of StatisticsInstitut de Recerca Sant Joan de DéuBarcelonaSpain
| | - Cristina Hernando‐Davalillo
- Department of Genetic and Molecular Medicine and Pediatric Institute of Rare DiseasesHospital Sant Joan de Déu BarcelonaBarcelonaSpain
| | - Juan Darío Ortigoza‐Escobar
- U‐703 Centre for Biomedical Research on Rare Diseases (CIBER‐ER)Instituto de Salud Carlos IIIBarcelonaSpain
- Movement Disorders Unit, Pediatric Neurology Department, Institut de RecercaHospital Sant Joan de Déu BarcelonaBarcelonaSpain
- European Reference Network for Rare Neurological Diseases (ERN‐RND)BarcelonaSpain
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3
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Menozzi E, Balint B, Latorre A, Valente EM, Rothwell JC, Bhatia KP. Twenty years on: Myoclonus-dystonia and ε-sarcoglycan - neurodevelopment, channel, and signaling dysfunction. Mov Disord 2019; 34:1588-1601. [PMID: 31449710 DOI: 10.1002/mds.27822] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/19/2019] [Accepted: 07/14/2019] [Indexed: 12/26/2022] Open
Abstract
Myoclonus-dystonia is a clinical syndrome characterized by a typical childhood onset of myoclonic jerks and dystonia involving the neck, trunk, and upper limbs. Psychiatric symptomatology, namely, alcohol dependence and phobic and obsessive-compulsive disorder, is also part of the clinical picture. Zonisamide has demonstrated effectiveness at reducing both myoclonus and dystonia, and deep brain stimulation seems to be an effective and long-lasting therapeutic option for medication-refractory cases. In a subset of patients, myoclonus-dystonia is associated with pathogenic variants in the epsilon-sarcoglycan gene, located on chromosome 7q21, and up to now, more than 100 different pathogenic variants of the epsilon-sarcoglycan gene have been described. In a few families with a clinical phenotype resembling myoclonus-dystonia associated with distinct clinical features, variants have been identified in genes involved in novel pathways such as calcium channel regulation and neurodevelopment. Because of phenotypic similarities with epsilon-sarcoglycan gene-related myoclonus-dystonia, these conditions can be collectively classified as "myoclonus-dystonia syndromes." In the present article, we present myoclonus-dystonia caused by epsilon-sarcoglycan gene mutations, with a focus on genetics and underlying disease mechanisms. Second, we review those conditions falling within the spectrum of myoclonus-dystonia syndromes, highlighting their genetic background and involved pathways. Finally, we critically discuss the normal and pathological function of the epsilon-sarcoglycan gene and its product, suggesting a role in the stabilization of the dopaminergic membrane via regulation of calcium homeostasis and in the neurodevelopmental process involving the cerebello-thalamo-pallido-cortical network. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Elisa Menozzi
- Department of Biomedical, Metabolic and Neural Sciences, University-Hospital of Modena and Reggio Emilia, Modena, Italy.,Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Bettina Balint
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Enza Maria Valente
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
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4
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Carecchio M, Magliozzi M, Copetti M, Ferraris A, Bernardini L, Bonetti M, Defazio G, Edwards MJ, Torrente I, Pellegrini F, Comi C, Bhatia KP, Valente EM. Defining the Epsilon-Sarcoglycan (SGCE) Gene Phenotypic Signature in Myoclonus-Dystonia: A Reappraisal of Genetic Testing Criteria. Mov Disord 2013; 28:787-94. [DOI: 10.1002/mds.25506] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 03/27/2013] [Accepted: 04/09/2013] [Indexed: 11/11/2022] Open
Affiliation(s)
- Miryam Carecchio
- Sobell Department of Motor Neuroscience and Movement Disorders; UCL Institute of Neurology; London United Kingdom
- Department of Neurology; Amedeo Avogadro University; Novara Italy
| | - Monia Magliozzi
- CSS-Mendel Laboratory; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Massimiliano Copetti
- Biostatistics Unit; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Alessandro Ferraris
- CSS-Mendel Laboratory; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Laura Bernardini
- CSS-Mendel Laboratory; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Monica Bonetti
- CSS-Mendel Laboratory; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Giovanni Defazio
- Department of Neurosciences and Sensory Organs; School of Motor Sciences; “Aldo Moro” University of Bari; Bari Italy
| | - Mark J. Edwards
- Sobell Department of Motor Neuroscience and Movement Disorders; UCL Institute of Neurology; London United Kingdom
| | - Isabella Torrente
- CSS-Mendel Laboratory; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
| | - Fabio Pellegrini
- Biostatistics Unit; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
- Laboratory of Clinical Epidemiology of Diabetes and Chronic Diseases; Consorzio Mario Negri Sud; Santa Maria Imbaro Italy
| | - Cristoforo Comi
- Department of Neurology; Amedeo Avogadro University; Novara Italy
| | - Kailash P. Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders; UCL Institute of Neurology; London United Kingdom
| | - Enza Maria Valente
- CSS-Mendel Laboratory; IRCCS Casa Sollievo della Sofferenza; San Giovanni Rotondo Italy
- Department of Medicine and Surgery; University of Salerno; Salerno Italy
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5
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Kojovic M, Pareés I, Lampreia T, Pienczk-Reclawowicz K, Xiromerisiou G, Rubio-Agusti I, Kramberger M, Carecchio M, Alazami AM, Brancati F, Slawek J, Pirtosek Z, Valente EM, Alkuraya FS, Edwards MJ, Bhatia KP. The syndrome of deafness-dystonia: clinical and genetic heterogeneity. Mov Disord 2013; 28:795-803. [PMID: 23418071 DOI: 10.1002/mds.25394] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Revised: 12/27/2012] [Accepted: 01/15/2013] [Indexed: 11/09/2022] Open
Abstract
The syndrome of deafness-dystonia is rare and refers to the association of hearing impairment and dystonia when these are dominant features of a disease. Known genetic causes include Mohr-Tranebjaerg syndrome, Woodhouse-Sakati syndrome, and mitochondrial disorders, but the cause frequently remains unidentified. The aim of the current study was to better characterize etiological and clinical aspects of deafness-dystonia syndrome. We evaluated 20 patients with deafness-dystonia syndrome who were seen during the period between 1994 and 2011. The cause was identified in only 7 patients and included methylmalonic aciduria, meningoencephalitis, perinatal hypoxic-ischemic injury, large genomic deletion on chromosome 7q21, translocase of inner mitochondrial membrane 8 homolog A (TIMM8A) mutation (Mohr-Tranebjaerg syndrome), and chromosome 2 open reading frame 37 (C2orf37) mutation (Woodhouse-Sakati syndrome). The age of onset and clinical characteristics in these patients varied, depending on the etiology. In 13 patients, the cause remained unexplained despite extensive work-up. In the group of patients who had unknown etiology, a family history for deafness and/or dystonia was present the majority of patients, suggesting a strong genetic component. Sensory-neural deafness always preceded dystonia. Two clinical patterns of deafness-dystonia syndrome were observed: patients who had an onset in childhood had generalized dystonia (10 of 13 patients) with frequent bulbar involvement, whereas patients who had a dystonia onset in adulthood had segmental dystonia (3 of 13 patients) with the invariable presence of laryngeal dystonia. Deafness-dystonia syndrome is etiologically and clinically heterogeneous, and most patients have an unknown cause. The different age at onset and variable family history suggest a heterogeneous genetic background, possibly including currently unidentified genetic conditions.
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Affiliation(s)
- Maja Kojovic
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, United Kingdom
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6
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Xiao J, Nance MA, LeDoux MS. Incomplete nonsense-mediated decay facilitates detection of a multi-exonic deletion mutation in SGCE. Clin Genet 2012; 84:276-80. [PMID: 23140253 DOI: 10.1111/cge.12059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 11/06/2012] [Accepted: 11/06/2012] [Indexed: 11/26/2022]
Abstract
Mutations in SGCE represent the major cause of the myoclonus-dystonia syndrome (DYT11), an autosomal dominant disorder of reduced penetrance. Virtually all affected individuals have myoclonus, which is concentrated in the upper extremities, neck and trunk. Over half of patients have dystonia, usually affecting the neck or arms. SGCE is maternally imprinted. Of the more than 70 SGCE mutations reported in the literature, 18 are large deletions disrupting at least one exon. Therefore, testing for exonic deletions should be considered in individuals with a classic phenotype in whom Sanger sequencing is unrevealing. However, standard methodologies for detection of exonic deletion mutations are expensive, labor intensive and can produce false negatives. Herein, we report the use of cDNA derived from leukocyte RNA to identify a deletion mutation (exons 4 and 5) of SGCE in a family with DYT11. Residual RNA from incomplete nonsense-mediated decay permitted reverse transcription to cDNA. Breakpoints of the 8939 bp heterozygous deletion were then defined with long-range polymerase chain reaction and Sanger sequencing. Use of cDNA generated by reverse transcription of leukocyte RNA can reduce the costs associated with diagnostic genetic testing and can facilitate detection of deletion mutations.
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Affiliation(s)
- J Xiao
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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7
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Birnbaum RY, Everman DB, Murphy KK, Gurrieri F, Schwartz CE, Ahituv N. Functional characterization of tissue-specific enhancers in the DLX5/6 locus. Hum Mol Genet 2012; 21:4930-8. [PMID: 22914741 DOI: 10.1093/hmg/dds336] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Disruption of distaless homeobox 5 and 6 (Dlx5/6) in mice results in brain, craniofacial, genital, ear and limb defects. In humans, chromosomal aberrations in the DLX5/6 region, some of which do not encompass DLX5/6, are associated with split hand/foot malformation 1 (SHFM1) as well as intellectual disability, craniofacial anomalies and hearing loss, suggesting that the disruption of DLX5/6 regulatory elements could lead to these abnormalities. Here, we characterized enhancers in the DLX5/6 locus whose tissue-specific expression and genomic location along with previously characterized enhancers correlate with phenotypes observed in individuals with chromosomal abnormalities. By analyzing chromosomal aberrations at 7q21, we refined the minimal SHFM1 critical region and used comparative genomics to select 26 evolutionary conserved non-coding sequences in this critical region for zebrafish enhancer assays. Eight of these sequences were shown to function as brain, olfactory bulb, branchial arch, otic vesicle and fin enhancers, recapitulating dlx5a/6a expression. Using a mouse enhancer assay, several of these zebrafish enhancers showed comparable expression patterns in the branchial arch, otic vesicle, forebrain and/or limb at embryonic day 11.5. Examination of the coordinates of various chromosomal rearrangements in conjunction with the genomic location of these tissue-specific enhancers showed a correlation with the observed clinical abnormalities. Our findings suggest that chromosomal abnormalities that disrupt the function of these tissue-specific enhancers could be the cause of SHFM1 and its associated phenotypes. In addition, they highlight specific enhancers in which mutations could lead to non-syndromic hearing loss, craniofacial defects or limb malformations.
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Affiliation(s)
- Ramon Y Birnbaum
- Department of Bioengineering and Therapeutic Sciences and 2Institute for Human Genetics, University of California-San Francisco, CA, USA
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8
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Abstract
The last 25 years have seen remarkable advances in our understanding of the genetic etiologies of dystonia, new approaches into dissecting underlying pathophysiology, and independent progress in identifying effective treatments. In this review we highlight some of these advances, especially the genetic findings that have taken us from phenomenological to molecular-based diagnoses. Twenty DYT loci have been designated and 10 genes identified, all based on linkage analyses in families. Hand in hand with these genetic findings, neurophysiological and imaging techniques have been employed that have helped illuminate the similarities and differences among the various etiological dystonia subtypes. This knowledge is just beginning to yield new approaches to treatment including those based on DYT1 animal models. Despite the lag in identifying genetically based therapies, effective treatments, including impressive benefits from deep brain stimulation and botulinum toxin chemodenervation, have marked the last 25 years. The challenge ahead includes continued advancement into understanding dystonia's many underlying causes and associated pathology and using this knowledge to advance treatment including preventing genetic disease expression.
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Affiliation(s)
- Laurie J Ozelius
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York, USA
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9
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Albanese A, Asmus F, Bhatia KP, Elia AE, Elibol B, Filippini G, Gasser T, Krauss JK, Nardocci N, Newton A, Valls-Solé J. EFNS guidelines on diagnosis and treatment of primary dystonias. Eur J Neurol 2011; 18:5-18. [PMID: 20482602 DOI: 10.1111/j.1468-1331.2010.03042.x] [Citation(s) in RCA: 261] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES to provide a revised version of earlier guidelines published in 2006. BACKGROUND primary dystonias are chronic and often disabling conditions with a widespread spectrum mainly in young people. DIAGNOSIS primary dystonias are classified as pure dystonia, dystonia plus or paroxysmal dystonia syndromes. Assessment should be performed using a validated rating scale for dystonia. Genetic testing may be performed after establishing the clinical diagnosis. DYT1 testing is recommended for patients with primary dystonia with limb onset before age 30, and in those with an affected relative with early-onset dystonia. DYT6 testing is recommended in early-onset or familial cases with cranio-cervical dystonia or after exclusion of DYT1. Individuals with early-onset myoclonus should be tested for mutations in the DYT11 gene. If direct sequencing of the DYT11 gene is negative, additional gene dosage is required to improve the proportion of mutations detected. A levodopa trial is warranted in every patient with early-onset primary dystonia without an alternative diagnosis. In patients with idiopathic dystonia, neurophysiological tests can help with describing the pathophysiological mechanisms underlying the disorder. TREATMENT botulinum toxin (BoNT) type A is the first-line treatment for primary cranial (excluding oromandibular) or cervical dystonia; it is also effective on writing dystonia. BoNT/B is not inferior to BoNT/A in cervical dystonia. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for primary generalized or cervical dystonia, after medication or BoNT have failed. DBS is less effective in secondary dystonia. This treatment requires a specialized expertise and a multidisciplinary team.
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Affiliation(s)
- A Albanese
- Istituto Neurologico Carlo Besta, Milan, Italy Università Cattolica del Sacro Cuore, Milan, Italy.
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10
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Abstract
Myoclonus dystonia syndrome (MDS) refers to a group of heterogeneous nondegenerative clinical conditions characterized by the association of myoclonus and dystonia as the only or prominent symptom. The "core" of MDS is represented by inherited myoclonus-dystonia (M-D), a disorder with autosomal-dominant inheritance and reduced penetrance, beginning in early childhood with a relatively benign course, with myoclonus as the most predominant and disabling symptom. Alcohol responsiveness and psychiatric symptoms are characteristic features. Mutations in the epsilon-sarcoglycan gene (SGCE, DYT11) represent the major genetic cause, but M-D is genetically heterogeneous. In a variable proportion of M-D patients no mutation is found, and at least one other locus (DYT15) has been linked to the disease. Patients with primary dystonia, with or without the DYT1 mutation, may show irregular and arrhythmic jerky movements associated with dystonia. Usually dystonia is the prominent symptom and the myoclonic jerk involves the same body region; this condition, currently defined as "myoclonic dystonia," is included in the spectrum of MDS. Dopa-responsive dystonia due to mutation in the GTP-CH gene and vitamin E deficiency can present with a phenotype of dystonia and myoclonus in combination; both conditions should be considered in the diagnostic approach to patients since they are potentially treatable.
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Affiliation(s)
- Nardo Nardocci
- Department of Child Neurology, Fondazione IRCCS Istituto Neurologico "C. Besta", Milan, Italy.
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11
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Saugier-Veber P, Doummar D, Barthez MA, Czernecki V, Drouot N, Apartis E, Bürglen L, Frebourg T, Roze E. Myoclonus dystonia plus syndrome due to a novel 7q21 microdeletion. Am J Med Genet A 2010; 152A:1244-9. [PMID: 20425829 DOI: 10.1002/ajmg.a.33369] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Myoclonus dystonia (M-D) is a rare genetic movement disorder characterized by a combination of myoclonic jerks and dystonia. It is usually due to mutations in the SGCE gene. We report on a patient with a typical M-D syndrome, but also short stature, microcephaly, and mental retardation. Molecular analysis showed no mutations within the SGCE gene but a microdeletion encompassing the SGCE gene in chromosome region 7q21. Array-CGH analysis showed that the deletion spanned approximately 1.88 Mb. We suggest that M-D plus patients with mental retardation, microcephaly, dysmorphism, or short stature, all frequently associated disorders, should be screened for 7q21 microdeletion. By examining previously published cases of mental retardation associated with pure 7q21 deletions, we identified two distinct regions of respectively 455 and 496 kb that are critical for mental retardation and growth retardation. Among the genes located within these regions, LOC253012, also known as HEPACAM2, is a good candidate for both mental retardation and microcephaly.
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12
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Additional cryptic CNVs in mentally retarded patients with apparently balanced karyotypes. Eur J Med Genet 2010; 53:227-33. [PMID: 20542150 DOI: 10.1016/j.ejmg.2010.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 06/01/2010] [Indexed: 01/01/2023]
Abstract
Apparently balanced chromosome abnormalities are occasionally associated with mental retardation (MR). These balanced rearrangements may disrupt genes. However, the phenotype may also be caused by small abnormalities present at the breakpoints or elsewhere in the genome. Conventional karyotyping is not instrumental for detecting small abnormalities because it only identifies genomic imbalances larger than 5-10 Mb. In contrast, high-resolution whole-genome arrays enable the detection of submicroscopic abnormalities in patients with apparently balanced rearrangements. Here, we report on the whole-genome analysis of 13 MR patients with previously detected balanced chromosomal abnormalities, five de novo, four inherited, and four of unknown inheritance, using Single Nucleotide Polymorphism (SNP) arrays. In all the cases, the patient had an abnormal phenotype. In one familial case and one unknown inheritance case, one of the parents had a phenotype which appeared identical to the patient's phenotype. Additional copy number variants (CNVs) were identified in eight patients. Three patients contained CNVs adjacent to one or either breakpoints. One of these patients showed four and two deletions near the breakpoints of a de novo pericentric inversion. In five patients we identified CNVs on chromosomes unrelated to the previously observed genomic imbalance. These data demonstrate that high-resolution array screening and conventional karyotyping is necessary to tie complex karyotypes to phenotypes of MR patients.
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13
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Kinugawa K, Vidailhet M, Clot F, Apartis E, Grabli D, Roze E. Myoclonus-dystonia: an update. Mov Disord 2009; 24:479-89. [PMID: 19117361 DOI: 10.1002/mds.22425] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Our knowledge of the clinical, neurophysiological, and genetic aspects of myoclonus-dystonia (M-D) has improved markedly in the recent years. Basic research has provided new insights into the complex dysfunctions involved in the pathogenesis of M-D. On the basis of a comprehensive literature search, this review summarizes current knowledge on M-D, with a focus on recent findings. We also propose modified diagnostic criteria and recommendations for clinical management.
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14
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Shimojima K, Yamamoto T. Investigation of the candidate region for trigonocephaly in a patient with monosomy 9p syndrome using array-CGH. Am J Med Genet A 2009; 149A:1076-80. [PMID: 19396833 DOI: 10.1002/ajmg.a.32783] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Keiko Shimojima
- International Research and Educational Institute for Integrated Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan
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15
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Shiura H, Nakamura K, Hikichi T, Hino T, Oda K, Suzuki-Migishima R, Kohda T, Kaneko-ishino T, Ishino F. Paternal deletion of Meg1/Grb10 DMR causes maternalization of the Meg1/Grb10 cluster in mouse proximal Chromosome 11 leading to severe pre- and postnatal growth retardation. Hum Mol Genet 2009; 18:1424-38. [PMID: 19174477 DOI: 10.1093/hmg/ddp049] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mice with maternal duplication of proximal Chromosome 11 (MatDp(prox11)), where Meg1/Grb10 is located, exhibit pre- and postnatal growth retardation. To elucidate the responsible imprinted gene for the growth abnormality, we examined the precise structure and regulatory mechanism of this imprinted region and generated novel model mice mimicking the pattern of imprinted gene expression observed in the MatDp(prox11) by deleting differentially methylated region of Meg1/Grb10 (Meg1-DMR). It was found that Cobl and Ddc, the neighboring genes of Meg1/Grb10, also comprise the imprinted region. We also found that the mouse-specific repeat sequence consisting of several CTCF-binding motifs in the Meg1-DMR functions as a silencer, suggesting that the Meg1/Grb10 imprinted region adopted a different regulatory mechanism from the H19/Igf2 region. Paternal deletion of the Meg1-DMR (+/DeltaDMR) caused both upregulation of the maternally expressed Meg1/Grb10 Type I in the whole body and Cobl in the yolk sac and loss of paternally expressed Meg1/Grb10 Type II and Ddc in the neonatal brain and heart, respectively, demonstrating maternalization of the entire Meg1/Grb10 imprinted region. We confirmed that the +/DeltaDMR mice exhibited the same growth abnormalities as the MatDp(prox11) mice. Fetal and neonatal growth was very sensitive to the expression level of Meg1/Grb10 Type I, indicating that the 2-fold increment of the Meg1/Grb10 Type I is one of the major causes of the growth retardation observed in the MatDp(prox11) and +/DeltaDMR mice. This suggests that the corresponding human GRB10 Type I plays an important role in the etiology of Silver-Russell syndrome caused by partial trisomy of 7p11-p13.
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Affiliation(s)
- Hirosuke Shiura
- Department of Epigenetics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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