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Butler MG, Hossain WA, Cowen N, Bhatnagar A. Chromosomal Microarray Study in Prader-Willi Syndrome. Int J Mol Sci 2023; 24:ijms24021220. [PMID: 36674736 PMCID: PMC9863005 DOI: 10.3390/ijms24021220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 01/11/2023] Open
Abstract
A high-resolution chromosome microarray analysis was performed on 154 consecutive individuals enrolled in the DESTINY PWS clinical trial for Prader-Willi syndrome (PWS). Of these 154 PWS individuals, 87 (56.5%) showed the typical 15q11-q13 deletion subtypes, 62 (40.3%) showed non-deletion maternal disomy 15 and five individuals (3.2%) had separate unexpected microarray findings. For example, one PWS male had Klinefelter syndrome with segmental isodisomy identified in both chromosomes 15 and X. Thirty-five (40.2%) of 87 individuals showed typical larger 15q11-q13 Type I deletion and 52 individuals (59.8%) showed typical smaller Type II deletion. Twenty-four (38.7%) of 62 PWS individuals showed microarray patterns indicating either maternal heterodisomy 15 subclass or a rare non-deletion (epimutation) imprinting center defect. Segmental isodisomy 15 was seen in 34 PWS subjects (54.8%) with 15q26.3, 15q14 and 15q26.1 bands most commonly involved and total isodisomy 15 seen in four individuals (6.5%). In summary, we report on PWS participants consecutively enrolled internationally in a single clinical trial with high-resolution chromosome microarray analysis to determine and describe an unbiased estimate of the frequencies and types of genetic defects and address potential at-risk genetic disorders in those with maternal disomy 15 subclasses in the largest PWS cohort studied to date.
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Affiliation(s)
- Merlin G. Butler
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., MS 4015, Kansas City, KS 66160, USA
- Correspondence:
| | - Waheeda A. Hossain
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., MS 4015, Kansas City, KS 66160, USA
| | - Neil Cowen
- Soleno Therapeutics, Inc., Redwood City, CA 94065, USA
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Butler MG, Cowen N, Bhatnagar A. Prader-Willi syndrome, deletion subtypes, and magnesium: Potential impact on clinical findings. Am J Med Genet A 2022; 188:3278-3286. [PMID: 36190479 PMCID: PMC9548494 DOI: 10.1002/ajmg.a.62928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 01/31/2023]
Abstract
Prader-Willi syndrome is a complex neurodevelopmental genetic imprinting disorder with severe congenital hypotonia, failure to thrive with learning and behavioral problems, and hyperphagia with obesity developing in early childhood. Those with the typical 15q11-q13 Type I deletion compared with the smaller Type II deletion have more severe neurobehavioral problems and differ by the absence of four genes in the 15q11.2 BP1-BP2 region. Two of the genes encode magnesium transporters supporting brain and neurological function and we report on magnesium levels in the two deletion groups of PWS participants. We measured baseline plasma magnesium and analyzed data from a PWS cohort with and without the Type I or Type II deletion. Significantly lower plasma magnesium levels were found in PWS participants with the larger Type I deletion and more so with females with Type I deletion compared with females having the Type II deletion, although magnesium levels remained within normal range in both subgroups. Those with PWS and the larger 15q11-q13 Type I deletion were more clinically affected than those with the smaller Type II deletion. Two of the four genes missing in those with the larger deletion code for magnesium transporters and may impact magnesium levels. Our study showed lower magnesium levels in those with the larger deletion which could contribute to neurobehavioral differences seen in the two separate 15q11-q13 deletion subtypes and in addition affect both glucose and insulin metabolism impacting comorbidities but will require more research.
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Affiliation(s)
- Merlin G Butler
- Department of Psychiatry & Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Neil Cowen
- Soleno Therapeutics, Inc., Redwood City, California, USA
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3
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Yang-Li D, Fei-Hong L, Hui-Wen Z, Ming-Sheng M, Xiao-Ping L, Li L, Yi W, Qing Z, Yong-Hui J, Chao-Chun Z. Recommendations for the diagnosis and management of childhood Prader-Willi syndrome in China. Orphanet J Rare Dis 2022; 17:221. [PMID: 35698200 PMCID: PMC9195308 DOI: 10.1186/s13023-022-02302-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 03/23/2022] [Indexed: 11/28/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a complex and multisystem neurobehavioral disease, which is caused by the lack of expression of paternally inherited imprinted genes on chromosome15q11.2-q13.1. The clinical manifestations of PWS vary with age. It is characterized by severe hypotonia with poor suck and feeding difficulties in the early infancy, followed by overeating in late infancy or early childhood and progressive development of morbid obesity unless the diet is externally controlled. Compared to Western PWS patients, Chinese patients have a higher ratio of deletion type. Although some rare disease networks, including PWS Cooperation Group of Rare Diseases Branch of Chinese Pediatric Society, Zhejiang Expert Group for PWS, were established recently, misdiagnosis, missed diagnosis and inappropriate intervention were usually noted in China. Therefore, there is an urgent need for an integrated multidisciplinary approach to facilitate early diagnosis and optimize management to improve quality of life, prevent complications, and prolong life expectancy. Our purpose is to evaluate the current literature and evidences on diagnosis and management of PWS in order to provide evidence-based guidelines for this disease, specially from China.
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Affiliation(s)
- Dai Yang-Li
- Children's Hospital of Zhejiang University School of Medicine, No. 3333 Binsheng Road, Hangzhou, 310003, China
| | - Luo Fei-Hong
- Children's Hospital of Fudan University, Shanghai, China
| | - Zhang Hui-Wen
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ma Ming-Sheng
- Peking Union Medical College Hospital, Beijing, China
| | - Luo Xiao-Ping
- Tongji Hospital, Tongji Medical College of HUST, Wuhan, China
| | - Liu Li
- Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Wang Yi
- Children's Hospital of Fudan University, Shanghai, China
| | - Zhou Qing
- Fujian Children's Hospital, Fuzhou, China
| | - Jiang Yong-Hui
- Yale University, 69 Lexington Gardens, Northern Haven, CT, 06473, USA.
| | - Zou Chao-Chun
- Children's Hospital of Zhejiang University School of Medicine, No. 3333 Binsheng Road, Hangzhou, 310003, China.
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A Review of Prader–Willi Syndrome. ENDOCRINES 2022. [DOI: 10.3390/endocrines3020027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Prader–Willi Syndrome (PWS, OMIM #176270) is a rare complex genetic disorder due to the loss of expression of paternally derived genes in the PWS critical region on chromosome 15q11-q13. It affects multiple neuroendocrine systems and may present failure to thrive in infancy, but then, hyperphagia and morbid obesity starting in early childhood became the hallmark of this condition. Short stature, hypogonadism, sleep abnormalities, intellectual disability, and behavioral disturbances highlight the main features of this syndrome. There have been a significant number of advances in our understanding of the genetic mechanisms underlying the disease, especially discoveries of MAGEL2, NDN, MKRN3, and SNORD116 genes in the pathophysiology of PWS. However, early diagnosis and difficulty in treating some of the disease’s most disabling features remain challenging. As our understanding of PWS continues to grow, so does the availability of new therapies and management strategies available to clinicians and families.
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Hypogonadism in Patients with Prader Willi Syndrome: A Narrative Review. Int J Mol Sci 2021; 22:ijms22041993. [PMID: 33671467 PMCID: PMC7922674 DOI: 10.3390/ijms22041993] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 12/20/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder related to the lack of a functional paternal copy of chromosome 15q11-q13. Several clinical manifestations are reported, such as short stature, cognitive and behavioral disability, temperature instability, hypotonia, hypersomnia, hyperphagia, and multiple endocrine abnormalities, including growth hormone deficiency and hypogonadism. The hypogonadism in PWS is due to central and peripheral mechanisms involving the hypothalamus-pituitary-gonadal axis. The early diagnosis and management of hypogonadism in PWS are both important for physicians in order to reach a better quality of life for these patients. The aim of this study is to summarize and investigate causes and possible therapies for hypogonadism in PWS. Additional studies are further needed to clarify the role of different genes related to hypogonadism and to establish a common and evidence-based therapy.
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Alves C, Franco RR. Prader-Willi syndrome: endocrine manifestations and management. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2020; 64:223-234. [PMID: 32555988 PMCID: PMC10522225 DOI: 10.20945/2359-3997000000248] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 02/28/2020] [Indexed: 11/23/2022]
Abstract
Prader-Willi syndrome (PWS) is a genetic disorder caused by the absence of gene expression in the 15q11.2-q13 paternal chromosome. Patients with PWS develop hypothalamic dysfunction that can lead to various endocrine changes such as: obesity, growth hormone deficiency, hypogonadism, hypothyroidism, adrenal insufficiency and low bone mineral density. In addition, individuals with PWS have increased risk of developing type 2 diabetes mellitus. This review summarizes and updates the current knowledge about the prevention, diagnosis and treatment of endocrine manifestations associated with Prader Willi syndrome, especially diagnosis of growth hormone deficiency, management and monitoring of adverse effects; diagnosis of central adrenal insufficiency and management in stressful situations; screening for central hypothyroidism; research and treatment of hypogonadism; prevention and treatment of disorders of glucose metabolism. Careful attention to the endocrine aspects of PWS contributes significantly to the health of these individuals. Arch Endocrinol Metab. 2020;64(3):223-34.
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Affiliation(s)
- Crésio Alves
- Hospital Universitário Prof. Edgard SantosFaculdade de MedicinaUniversidade Federal da BahiaSalvadorBABrasil Unidade de Endocrinologia Pediátrica, Hospital Universitário Prof. Edgard Santos, Faculdade de Medicina, Universidade Federal da Bahia (UFBA), Salvador, BA, Brasil
| | - Ruth Rocha Franco
- Hospital das ClínicasFaculdade de MedicinaUniversidade de São PauloSão PauloSPBrasil Ambulatório de Prader-Willi, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brasil
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Food and Non-Food-Related Behavior across Settings in Children with Prader-Willi Syndrome. Genes (Basel) 2020; 11:genes11020204. [PMID: 32079283 PMCID: PMC7074075 DOI: 10.3390/genes11020204] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 12/03/2022] Open
Abstract
This study sought to describe food- and non-food-related behaviors of children aged 3 to 18 years with Prader–Willi syndrome (PWS) in home and school settings, as assessed by 86 parents and 63 teachers using 7 subscales of the Global Assessment of Individual’s Behavior (GAIB). General Behavior Problem, Non-Food-Related Behavior Problem, and Non-Food-Related Obsessive Speech and Compulsive Behavior (OS/CB) scores did not differ significantly between parent and teacher reports. Food-Related Behavior Problem scores were higher in parent versus teacher reports when the mother had less than a college education (difference of 13.6 points, 95% Confidence Interval (CI) 5.1 to 22). Parents assigned higher Food-Related OS/CB scores than teachers (difference of 5.7 points, 95% CI 2.4 to 9.0). Although teachers reported fewer Food-Related OS/CB, they scored overall OS/CB higher for interfering with daily activities compared with parents (difference of 0.9 points, 95% CI 0.4 to 1.4). Understanding how behaviors manifest in home and school settings, and how they vary with socio-demographic and patient characteristics can help inform strategies to reduce behavior problems and improve outcomes.
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Magnesium Supplement and the 15q11.2 BP1-BP2 Microdeletion (Burnside-Butler) Syndrome: A Potential Treatment? Int J Mol Sci 2019; 20:ijms20122914. [PMID: 31207912 PMCID: PMC6627575 DOI: 10.3390/ijms20122914] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 12/14/2022] Open
Abstract
The 15q11.2 BP1–BP2 microdeletion (Burnside–Butler) syndrome is an emerging disorder that encompasses four genes (NIPA1, NIPA2, CYFIP1, and TUBGCP5). When disturbed, these four genes can lead to cognitive impairment, language and/or motor delay, psychiatric/behavioral problems (attention-deficit hyperactivity, autism, dyslexia, schizophrenia/paranoid psychosis), ataxia, seizures, poor coordination, congenital anomalies, and abnormal brain imaging. This microdeletion was reported as the most common cytogenetic finding when using ultra-high- resolution chromosomal microarrays in patients presenting for genetic services due to autism with or without additional clinical features. Additionally, those individuals with Prader–Willi or Angelman syndromes having the larger typical 15q11–q13 type I deletion which includes the 15q11.2 BP1–BP2 region containing the four genes, show higher clinical severity than those having the smaller 15q11–q13 deletion where these four genes are intact. Two of the four genes (i.e., NIPA1 and NIPA2) are expressed in the brain and encode magnesium transporters. Magnesium is required in over 300 enzyme systems that are critical for multiple cellular functions, energy expenditure, protein synthesis, DNA transcription, and muscle and nerve function. Low levels of magnesium are found in those with seizures, depression, and acute or chronic brain diseases. Anecdotally, parents have administered magnesium supplements to their children with the 15q11.2 BP1–BP2 microdeletion and have observed improvement in behavior and clinical presentation. These observations require more attention from the medical community and should include controlled studies to determine if magnesium supplements could be a treatment option for this microdeletion syndrome and also for a subset of individuals with Prader–Willi and Angelman syndromes.
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Butler MG, Miller JL, Forster JL. Prader-Willi Syndrome - Clinical Genetics, Diagnosis and Treatment Approaches: An Update. Curr Pediatr Rev 2019; 15:207-244. [PMID: 31333129 PMCID: PMC7040524 DOI: 10.2174/1573396315666190716120925] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Prader-Willi Syndrome (PWS) is a neurodevelopmental genomic imprinting disorder with lack of expression of genes inherited from the paternal chromosome 15q11-q13 region usually from paternal 15q11-q13 deletions (about 60%) or maternal uniparental disomy 15 or both 15s from the mother (about 35%). An imprinting center controls the expression of imprinted genes in the chromosome 15q11-q13 region. Key findings include infantile hypotonia, a poor suck, failure to thrive and hypogonadism/hypogenitalism. Short stature and small hands/feet due to growth and other hormone deficiencies, hyperphagia and marked obesity occur in early childhood, if uncontrolled. Cognitive and behavioral problems (tantrums, compulsions, compulsive skin picking) are common. OBJECTIVE Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS. This report will describe an accurate diagnosis with determination of specific genetic subtypes, appropriate medical management and best practice treatment approaches. METHODS AND RESULTS An extensive literature review was undertaken related to genetics, clinical findings and laboratory testing, clinical and behavioral assessments and summary of updated health-related information addressing the importance of early PWS diagnosis and treatment. A searchable, bulleted and formatted list of topics is provided utilizing a Table of Contents approach for the clinical practitioner. CONCLUSION Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections pertinent in the context of clinical practice. Frequently asked questions by clinicians, families and other interested participants or providers will be addressed.
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Affiliation(s)
- Merlin G Butler
- Departments of Psychiatry & Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States
| | - Jennifer L Miller
- Department of Pediatrics, University of Florida School of Medicine, Gainesville, FL, United States
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Geets E, Meuwissen MEC, Van Hul W. Clinical, molecular genetics and therapeutic aspects of syndromic obesity. Clin Genet 2018; 95:23-40. [PMID: 29700824 DOI: 10.1111/cge.13367] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/05/2018] [Accepted: 04/16/2018] [Indexed: 12/13/2022]
Abstract
Obesity has become a major health problem worldwide. To date, more than 25 different syndromic forms of obesity are known in which one (monogenic) or multiple (polygenic) genes are involved. This review gives an overview of these forms and focuses more in detail on 6 syndromes: Prader Willi Syndrome and Prader Willi like phenotype, Bardet Biedl Syndrome, Alström Syndrome, Wilms tumor, Aniridia, Genitourinary malformations and mental Retardation syndrome and 16p11.2 (micro)deletions. Years of research provided plenty of information on the molecular genetics of these disorders and the obesity phenotype leading to a more individualized treatment of the symptoms, however, many questions still remain unanswered. As these obesity syndromes have different signs and symptoms in common, it makes it difficult to accurately diagnose patients which may result in inappropriate treatment of the disease. Therefore, the big challenge for clinicians and scientists is to more clearly differentiate all syndromic forms of obesity to provide conclusive genetic explanations and eventually deliver accurate genetic counseling and treatment. In addition, further delineation of the (functions of the) underlying genes with the use of array- or next-generation sequencing-based technology will be helpful to unravel the mechanisms of energy metabolism in the general population.
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Affiliation(s)
- E Geets
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - M E C Meuwissen
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - W Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
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Butler MG, Kimonis V, Dykens E, Gold JA, Miller J, Tamura R, Driscoll DJ. Prader-Willi syndrome and early-onset morbid obesity NIH rare disease consortium: A review of natural history study. Am J Med Genet A 2017; 176:368-375. [PMID: 29271568 DOI: 10.1002/ajmg.a.38582] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 11/22/2017] [Accepted: 11/27/2017] [Indexed: 02/04/2023]
Abstract
We describe the National Institutes of Health rare disease consortium for Prader-Willi syndrome (PWS) developed to address concerns regarding medical care, diagnosis, growth and development, awareness, and natural history. PWS results from errors in genomic imprinting leading to loss of paternally expressed genes due to 15q11-q13 deletion, maternal disomy 15 or imprinting defects. The 8 year study was conducted at four national sites on individuals with genetically confirmed PWS and early-onset morbid obesity (EMO) with data accumulated to gain a better understanding of the natural history, cause and treatment of PWS. Enrollment of 355 subjects with PWS and 36 subjects with EMO began in September 2006 with study completion in July 2014. Clinical, genetic, cognitive, behavior, and natural history data were systematically collected along with PWS genetic subtypes, pregnancy and birth history, mortality, obesity, and cognitive status with study details as important endpoints in both subject groups. Of the 355 individuals with PWS, 217 (61%) had the 15q11-q13 deletion, 127 (36%) had maternal disomy 15, and 11 (3%) had imprinting defects. Six deaths were reported in our PWS cohort with 598 cumulative years of study exposure and one death in the EMO group with 42 years of exposure. To our knowledge, this description of a longitudinal study in PWS represents the largest and most comprehensive cohort useful for investigators in planning comparable studies in other rare disorders. Ongoing studies utilizing this database should have a direct impact on care and services, diagnosis, treatment, genotype-phenotype correlations, and clinical outcomes in PWS.
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Affiliation(s)
| | | | | | - June A Gold
- University of California, Irvine, California
| | | | - Roy Tamura
- University of South Florida, Tampa, Florida
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Butler MG. Clinical and genetic aspects of the 15q11.2 BP1-BP2 microdeletion disorder. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2017; 61:568-579. [PMID: 28387067 PMCID: PMC5464369 DOI: 10.1111/jir.12382] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/09/2017] [Accepted: 03/09/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND The 15q11.2 BP1-BP2 microdeletion (Burnside-Butler susceptibility locus) is an emerging condition with over 200 individuals reported in the literature. TUBGCP5, CFYIP1, NIPA1 and NIPA2 genes are located in this chromosome 15 region and when disturbed individually are known to cause neurological, cognitive or behavioural problems as well as playing a role in both Prader-Willi and Angelman syndromes. These syndromes were the first examples in humans of genomic imprinting and typically caused by a deletion but involving the distal chromosome 15q11-q13 breakpoint BP3 and proximally placed breakpoints BP1 or BP2 of different parental origin. The typical 15q11-q13 deletion involves BP1 and BP3 and the typical type II deletion at BP2 and BP3. Several studies have shown that individuals with the larger type I deletion found in both Prader-Willi and Angelman syndromes are reported with more severe neurodevelopmental symptoms compared to those individuals with the smaller type II deletion. METHODS The literature was reviewed and clinical and cytogenetic findings summarised in 200 individuals with this microdeletion along with the role of deleted genes in diagnosis, medical care and counseling of those affected and their family members. RESULTS Reported findings in this condition include developmental delays (73% of cases) and language impairment (67%) followed by motor delay (42%), attention deficit disorder/attention deficit hyperactivity disorder (35%) and autism spectrum disorder (27%). The de novo deletion frequency has been estimated at 5 to 22% with low penetrance possibly related to subclinical manifestation or incomplete clinical information on family members. A prevalence of 0.6 to 1.3% has been identified in one study for patients with neurological or behavioural problems presenting for genetic services and chromosomal microarray analysis. CONCLUSIONS The summarised results indicate that chromosome 15q11.2 BP1-BP2 microdeletion is emerging as one of the most common cytogenetic abnormalities seen in individuals with intellectual impairment, autism spectrum disorder and other related behavioural or clinical findings, but more research is needed.
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Affiliation(s)
- Merlin G. Butler
- University of Kansas Medical Center, Departments of Psychiatry & Behavioral Sciences and Pediatrics, Kansas City, KS USA
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Windholz J, Kovacs P, Schlicke M, Franke C, Mahajan A, Morris AP, Lemke JR, Klammt J, Kiess W, Schöneberg T, Pfäffle R, Körner A. Copy number variations in "classical" obesity candidate genes are not frequently associated with severe early-onset obesity in children. J Pediatr Endocrinol Metab 2017; 30:507-515. [PMID: 28593922 DOI: 10.1515/jpem-2016-0435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/06/2017] [Indexed: 11/15/2022]
Abstract
BACKGROUND Obesity is genetically heterogeneous and highly heritable, although polymorphisms explain the phenotype in only a small proportion of obese children. We investigated the presence of copy number variations (CNVs) in "classical" genes known to be associated with (monogenic) early-onset obesity in children. METHODS In 194 obese Caucasian children selected for early-onset and severe obesity from our obesity cohort we screened for deletions and/or duplications by multiplex ligation-dependent probe amplification reaction (MLPA). As we found one MLPA probe to interfere with a polymorphism in SIM1 we investigated its association with obesity and other phenotypic traits in our extended cohort of 2305 children. RESULTS In the selected subset of most severely obese children, we did not find CNV with MLPA in POMC, LEP, LEPR, MC4R, MC3R or MC2R genes. However, one SIM1 probe located at exon 9 gave signals suggestive for SIM1 insufficiency in 52 patients. Polymerase chain reaction (PCR) analysis identified this as a false positive result due to interference with single nucleotide polymorphism (SNP) rs3734354/rs3734355. We, therefore, investigated for associations of this polymorphism with obesity and metabolic traits in our extended cohort. We found rs3734354/rs3734355 to be associated with body mass index-standard deviation score (BMI-SDS) (p = 0.003), but not with parameters of insulin metabolism, blood pressure or food intake. CONCLUSIONS In our modest sample of severely obese children, we were unable to find CNVs in well-established monogenic obesity genes. Nevertheless, we found an association of rs3734354 in SIM1 with obesity of early-onset type in children, although not with obesity-related traits.
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Affiliation(s)
- Jan Windholz
- Pediatric Research Center, University Hospital for Children and Adolescents, Medical Faculty, University of Leipzig, Leipzig
| | - Peter Kovacs
- Leipzig University Medical Center, IFB AdiposityDiseases, University of Leipzig, Leipzig
| | - Marina Schlicke
- Pediatric Research Center, University Hospital for Children and Adolescents, Medical Faculty, University of Leipzig, Leipzig
| | - Christin Franke
- Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, University of Leipzig, Leipzig
| | - Anubha Mahajan
- Wellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford
| | - Andrew P Morris
- Wellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford
| | - Johannes R Lemke
- Institute of Human Genetics, Medical Faculty, University of Leipzig, Leipzig
| | - Jürgen Klammt
- Pediatric Research Center, University Hospital for Children and Adolescents, Medical Faculty, University of Leipzig, Leipzig
| | - Wieland Kiess
- Pediatric Research Center, University Hospital for Children and Adolescents, Medical Faculty, University of Leipzig, Leipzig
| | - Torsten Schöneberg
- Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, University of Leipzig, Leipzig
| | - Roland Pfäffle
- Pediatric Research Center, University Hospital for Children and Adolescents, Medical Faculty, University of Leipzig, Leipzig
| | - Antje Körner
- Pediatric Research Center, University Hospital for Children and Adolescents, Medical Faculty, University of Leipzig, Leipzig
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Karger L, Khan WA, Calabio R, Singh R, Xiang B, Babu A, Cohen N, Yang AC, Scott SA. Maternal uniparental disomy of chromosome 15 and concomitant STRC and CATSPER2 deletion-mediated deafness-infertility syndrome. Am J Med Genet A 2017; 173:1436-1439. [PMID: 28317263 DOI: 10.1002/ajmg.a.38154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/03/2017] [Accepted: 01/06/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Lisa Karger
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Wahab A Khan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rafaela Calabio
- Division of Neonatology, Mount Sinai West, New York, New York
| | - Ram Singh
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Bixia Xiang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Arvind Babu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Ninette Cohen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Amy C Yang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Stuart A Scott
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
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Dang V, Surampalli A, Manzardo AM, Youn S, Butler MG, Gold JA, Kimonis VE. Prader-Willi Syndrome due to an Unbalanced de novo Translocation t(15;19)(q12;p13.3). Cytogenet Genome Res 2016; 150:29-34. [PMID: 27894106 DOI: 10.1159/000452611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2016] [Indexed: 11/19/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a complex, multisystem genetic disorder characterized by endocrine, neurologic, and behavioral abnormalities. We report the first case of an unbalanced de novo reciprocal translocation of chromosomes 15 and 19, 45,XY,-15,der(19)t(15;19)(q12;p13.3), resulting in monosomy for the PWS critical chromosome region. Our patient had several typical features of PWS including infantile hypotonia, a poor suck and feeding difficulties, tantrums, skin picking, compulsions, small hands and feet, and food seeking, but not hypopigmentation, a micropenis, cryptorchidism or obesity as common findings seen in PWS at the time of examination at 6 years of age. He had seizures noted from 1 to 3 years of age and marked cognitive delay. High-resolution SNP microarray analysis identified an atypical PWS type I deletion in chromosome 15 involving the proximal breakpoint BP1. The deletion extended beyond the GABRB3 gene but was proximal to the usual distal breakpoint (BP3) within the 15q11q13 region, and GABRA5, GABRG3, and OCA2 genes were intact. No deletion of band 19p13.3 was detected; therefore, the patient was not at an increased risk of tumors from the Peutz-Jeghers syndrome associated with a deletion of the STK11 gene.
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Affiliation(s)
- Vy Dang
- Division of Genetics and Genomic Medicine, Department of Pediatrics, University of California, Irvine, Calif., USA
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Cheon CK. Genetics of Prader-Willi syndrome and Prader-Will-Like syndrome. Ann Pediatr Endocrinol Metab 2016; 21:126-135. [PMID: 27777904 PMCID: PMC5073158 DOI: 10.6065/apem.2016.21.3.126] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 09/30/2016] [Indexed: 11/29/2022] Open
Abstract
The Prader-Willi syndrome (PWS) is a human imprinting disorder resulting from genomic alterations that inactivate imprinted, paternally expressed genes in human chromosome region 15q11-q13. This genetic condition appears to be a contiguous gene syndrome caused by the loss of at least 2 of a number of genes expressed exclusively from the paternal allele, including SNRPN, MKRN3, MAGEL2, NDN and several snoRNAs, but it is not yet well known which specific genes in this region are associated with this syndrome. Prader-Will-Like syndrome (PWLS) share features of the PWS phenotype and the gene functions disrupted in PWLS are likely to lie in genetic pathways that are important for the development of PWS phenotype. However, the genetic basis of these rare disorders differs and the absence of a correct diagnosis may worsen the prognosis of these individuals due to the endocrine-metabolic malfunctioning associated with the PWS. Therefore, clinicians face a challenge in determining when to request the specific molecular test used to identify patients with classical PWS because the signs and symptoms of PWS are common to other syndromes such as PWLS. This review aims to provide an overview of current knowledge relating to the genetics of PWS and PWLS, with an emphasis on identification of patients that may benefit from further investigation and genetic screening.
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Affiliation(s)
- Chong Kun Cheon
- Division of Pediatric Endocrinology and Metabolism, Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Korea
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Han JY, Park J, Jang W, Chae H, Kim M, Kim Y. A twin sibling with Prader-Willi syndrome caused by type 2 microdeletion following assisted reproductive technology: A case report. Biomed Rep 2016; 5:18-22. [PMID: 27330749 PMCID: PMC4906703 DOI: 10.3892/br.2016.675] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/19/2016] [Indexed: 11/26/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a neurobehavioral imprinting disorder, which arises due to an absence of paternally expressed genes within the 15q11.2-q13 region. This occurs via one of the three main genetic mechanisms, as follows: Deletion of the paternally inherited 15q11.2-q13 region, maternal uniparental disomy and imprinting defect. Recent studies have reported an association between imprinting disorders and assisted reproductive technologies (ART). The current study presents a 6-year-old female patient who is a dizygotic twin, in which one was born with de novo microdeletion at 15q11.2-q13.1 following in vitro fertilization. The patient had characteristic facial features including narrow bifrontal diameter, strabismus, downturned mouth, feeding problems and generalized hypotonia during infancy, developmental delay, mental retardation and rapid weight gain. Based upon phenotypic resemblance and the medical records, methylation-specific multiplex ligation-dependent probe amplification and array-based comparative genome hybridization analyses demonstrate type 2 microdeletion between breaking point 2 (BP2) and BP3, which occur from MKRN3 through HERC2 at 15q11.2-q13.1. To the best of our knowledge, the present study is the first to report a PWS case born following ART reported in South Korea. In addition to previous studies, the present study contributes to the consensus regarding genotype-phenotype comparisons in this respect.
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Affiliation(s)
- Ji Yoon Han
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Joonhong Park
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea; Catholic Genetic Laboratory Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Woori Jang
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea; Catholic Genetic Laboratory Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Hyojin Chae
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea; Catholic Genetic Laboratory Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Myungshin Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea; Catholic Genetic Laboratory Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Yonggoo Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea; Catholic Genetic Laboratory Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
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Butler MG. Single Gene and Syndromic Causes of Obesity: Illustrative Examples. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 140:1-45. [PMID: 27288824 DOI: 10.1016/bs.pmbts.2015.12.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Obesity is a significant health problem in westernized societies, particularly in the United States where it has reached epidemic proportions in both adults and children. The prevalence of childhood obesity has doubled in the past 30 years. The causation is complex with multiple sources, including an obesity promoting environment with plentiful highly dense food sources and overall decreased physical activity noted for much of the general population, but genetic factors clearly play a role. Advances in genetic technology using candidate gene approaches, genome-wide association studies, structural and expression microarrays, and next generation sequencing have led to the discovery of hundreds of genes recognized as contributing to obesity. Polygenic and monogenic causes of obesity are now recognized including dozens of examples of syndromic obesity with Prader-Willi syndrome, as a classical example and recognized as the most common known cause of life-threatening obesity. Genetic factors playing a role in the causation of obesity will be discussed along with the growing evidence of single genes and the continuum between monogenic and polygenic obesity. The clinical and genetic aspects of four classical but rare obesity-related syndromes (ie, Prader-Willi, Alström, fragile X, and Albright hereditary osteodystrophy) will be described and illustrated in this review of single gene and syndromic causes of obesity.
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Affiliation(s)
- Merlin G Butler
- Departments of Psychiatry & Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States of America.
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Butler MG, Manzardo AM, Forster JL. Prader-Willi Syndrome: Clinical Genetics and Diagnostic Aspects with Treatment Approaches. Curr Pediatr Rev 2016; 12:136-66. [PMID: 26592417 PMCID: PMC6742515 DOI: 10.2174/1573396312666151123115250] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND Prader-Willi syndrome (PWS) is a neuro-developmental genetic disorder due to lack of expression of genes inherited from the paternal chromosome 15q11-q13 region with three main genetic subtypes. These include paternal 15q11-q13 deletion (about 70% of cases), maternal uniparental disomy 15 or both 15s from the mother (20-30% of cases), and defects in the imprinting center (1-3%) which controls the expression of imprinted genes in this chromosome region. Clinical manifestations include infantile hypotonia with a poor suck resulting in failure to thrive, short stature, small hands/feet and hypogonadism/hypogenitalism due to growth and other hormone deficiencies, hyperphagia and excessive weight gain with obesity and cognitive and behavioral problems including obsessive compulsions, tantrums and self-injury. The phenotype is likely related to hypothalamic dysfunction. OBJECTIVE Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS requiring accurate diagnosis, appropriate medical management and treatment; the major objective of our report. METHODS AND RESULTS An extensive review of the literature was undertaken including genetics, clinical and behavioral aspects, and updated health-related information addressing the importance of early diagnosis and treatment of individuals with Prader-Willi syndrome. A searchable, bulleted and formatted list of topics related to this obesity syndrome was provided utilizing a Table of Contents approach for the clinical practitioner. CONCLUSIONS Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections that are pertinent in the context of clinical practice. Finally, frequently asked questions by clinicians, families and other interested participants will be addressed.
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Affiliation(s)
- Merlin G Butler
- University of Kansas Medical Center, Department of Psychiatry and Behavioral Sciences, 3901 Rainbow Boulevard, MS 4015, Kansas City, Kansas 66160, USA.
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Angulo MA, Butler MG, Cataletto ME. Prader-Willi syndrome: a review of clinical, genetic, and endocrine findings. J Endocrinol Invest 2015; 38:1249-63. [PMID: 26062517 PMCID: PMC4630255 DOI: 10.1007/s40618-015-0312-9] [Citation(s) in RCA: 350] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/11/2015] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. There are three main genetic subtypes in PWS: paternal 15q11-q13 deletion (65-75 % of cases), maternal uniparental disomy 15 (20-30 % of cases), and imprinting defect (1-3 %). DNA methylation analysis is the only technique that will diagnose PWS in all three molecular genetic classes and differentiate PWS from Angelman syndrome. Clinical manifestations change with age with hypotonia and a poor suck resulting in failure to thrive during infancy. As the individual ages, other features such as short stature, food seeking with excessive weight gain, developmental delay, cognitive disability and behavioral problems become evident. The phenotype is likely due to hypothalamic dysfunction, which is responsible for hyperphagia, temperature instability, high pain threshold, hypersomnia and multiple endocrine abnormalities including growth hormone and thyroid-stimulating hormone deficiencies, hypogonadism and central adrenal insufficiency. Obesity and its complications are the major causes of morbidity and mortality in PWS. METHODS An extensive review of the literature was performed and interpreted within the context of clinical practice and frequently asked questions from referring physicians and families to include the current status of the cause and diagnosis of the clinical, genetics and endocrine findings in PWS. CONCLUSIONS Updated information regarding the early diagnosis and management of individuals with Prader-Willi syndrome is important for all physicians and will be helpful in anticipating and managing or modifying complications associated with this rare obesity-related disorder.
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Affiliation(s)
- M A Angulo
- Department of Pediatrics, Winthrop University Hospital, 101 Mineola Blvd, 2nd Floor, Mineola, NY, 11501, USA.
| | - M G Butler
- Department of Psychiatry and Behavioral Sciences and Pediatrics, University of Kansas Medical Center, 3901 Rainbow Blvd, MS 4015, Kansas City, KS, 66160, USA.
| | - M E Cataletto
- Department of Pediatrics, Winthrop University Hospital, 120 Mineola Blvd, Suite210, Mineola, NY, 11501, USA.
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Massah S, Beischlag TV, Prefontaine GG. Epigenetic events regulating monoallelic gene expression. Crit Rev Biochem Mol Biol 2015; 50:337-58. [PMID: 26155735 DOI: 10.3109/10409238.2015.1064350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In mammals, generally it is assumed that the genes inherited from each parent are expressed to similar levels. However, it is now apparent that in non-sex chromosomes, 6-10% of genes are selected for monoallelic expression. Monoallelic expression or allelic exclusion is established either in an imprinted (parent-of-origin) or a stochastic manner. The stochastic model explains random selection while the imprinted model describes parent-of-origin specific selection of alleles for expression. Allelic exclusion occurs during X chromosome inactivation, parent-of-origin expression of imprinted genes and stochastic monoallelic expression of cell surface molecules, clustered protocadherin (PCDH) genes. Mis-regulation or loss of allelic exclusion contributes to developmental diseases. Epigenetic mechanisms are fundamental players that determine this type of expression despite a homogenous genetic background. DNA methylation and histone modifications are two mediators of the epigenetic phenomena. The majority of DNA methylation is found on cytosines of the CpG dinucleotide in mammals. Several covalent modifications of histones change the electrostatic forces between DNA and histones modifying gene expression. Long-range chromatin interactions organize chromatin into transcriptionally permissive and prohibitive regions leading to simultaneous regulation of gene expression and repression. Non-coding RNAs (ncRNAs) are also players in regulating gene expression. Together, these epigenetic mechanisms fine-tune gene expression levels essential for normal development and survival. In this review, first we discuss what is known about monoallelic gene expression. Then, we focus on the molecular mechanisms that regulate expression of three monoallelically expressed gene classes: the X-linked genes, selected imprinted genes and PCDH genes.
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Affiliation(s)
- Shabnam Massah
- a The Faculty of Health Sciences , Simon Fraser University , Burnaby , BC , Canada
| | - Timothy V Beischlag
- a The Faculty of Health Sciences , Simon Fraser University , Burnaby , BC , Canada
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Cox DM, Butler MG. The 15q11.2 BP1-BP2 microdeletion syndrome: a review. Int J Mol Sci 2015; 16:4068-82. [PMID: 25689425 PMCID: PMC4346944 DOI: 10.3390/ijms16024068] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/03/2015] [Accepted: 02/10/2015] [Indexed: 11/16/2022] Open
Abstract
Patients with the 15q11.2 BP1–BP2 microdeletion can present with developmental and language delay, neurobehavioral disturbances and psychiatric problems. Autism, seizures, schizophrenia and mild dysmorphic features are less commonly seen. The 15q11.2 BP1–BP2 microdeletion involving four genes (i.e., TUBGCP5, CYFIP1, NIPA1, NIPA2) is emerging as a recognized syndrome with a prevalence ranging from 0.57%–1.27% of patients presenting for microarray analysis which is a two to four fold increase compared with controls. Review of clinical features from about 200 individuals were grouped into five categories and included developmental (73%) and speech (67%) delays; dysmorphic ears (46%) and palatal anomalies (46%); writing (60%) and reading (57%) difficulties, memory problems (60%) and verbal IQ scores ≤75 (50%); general behavioral problems, unspecified (55%) and abnormal brain imaging (43%). Other clinical features noted but not considered as common were seizures/epilepsy (26%), autism spectrum disorder (27%), attention deficit disorder (ADD)/attention deficit hyperactivity disorder (ADHD) (35%), schizophrenia/paranoid psychosis (20%) and motor delay (42%). Not all individuals with the deletion are clinically affected, yet the collection of findings appear to share biological pathways and presumed genetic mechanisms. Neuropsychiatric and behavior disturbances and mild dysmorphic features are associated with genomic imbalances of the 15q11.2 BP1–BP2 region, including microdeletions, but with an apparent incomplete penetrance and variable expressivity.
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Affiliation(s)
- Devin M Cox
- Departments of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Boulevard, MS 4015, Kansas City, KS 66160, USA.
| | - Merlin G Butler
- Departments of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, 3901 Rainbow Boulevard, MS 4015, Kansas City, KS 66160, USA.
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Butler MG, Wang K, Marshall JD, Naggert JK, Rethmeyer JA, Gunewardena SS, Manzardo AM. Coding and noncoding expression patterns associated with rare obesity-related disorders: Prader-Willi and Alström syndromes. ACTA ACUST UNITED AC 2015; 2015:53-75. [PMID: 25705109 DOI: 10.2147/agg.s74598] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Obesity is accompanied by hyperphagia in several classical genetic obesity-related syndromes that are rare, including Prader-Willi syndrome (PWS) and Alström syndrome (ALMS). We compared coding and noncoding gene expression in adult males with PWS, ALMS, and nonsyndromic obesity relative to nonobese males using readily available lymphoblastoid cells to identify disease-specific molecular patterns and disturbed mechanisms in obesity. We found 231 genes upregulated in ALMS compared with nonobese males, but no genes were found to be upregulated in obese or PWS males and 124 genes were downregulated in ALMS. The metallothionein gene (MT1X) was significantly downregulated in ALMS, in common with obese males. Only the complex SNRPN locus was disturbed (downregulated) in PWS along with several downregulated small nucleolar RNAs (snoRNAs) in the 15q11-q13 region (SNORD116, SNORD109B, SNORD109A, SNORD107). Eleven upregulated and ten downregulated snoRNAs targeting multiple genes impacting rRNA processing, developmental pathways, and associated diseases were found in ALMS. Fifty-two miRNAs associated with multiple, overlapping gene expression disturbances were upregulated in ALMS, and four were shared with obese males but not PWS males. For example, seven passenger strand microRNAs (miRNAs) (miR-93*, miR-373*, miR-29b-2*, miR-30c-1*, miR27a*, miR27b*, and miR-149*) were disturbed in association with six separate downregulated target genes (CD68, FAM102A, MXI1, MYO1D, TP53INP1, and ZRANB1). Cell cycle (eg, PPP3CA), transcription (eg, POLE2), and development may be impacted by upregulated genes in ALMS, while downregulated genes were found to be involved with metabolic processes (eg, FABP3), immune responses (eg, IL32), and cell signaling (eg, IL1B). The high number of gene and noncoding RNA disturbances in ALMS contrast with observations in PWS and males with nonsyndromic obesity and may reflect the progressing multiorgan pathology of the ALMS disease process.
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Affiliation(s)
- Merlin G Butler
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA ; Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Kun Wang
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
| | | | | | - Jasmine A Rethmeyer
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
| | - Sumedha S Gunewardena
- Department of Biostatistics, Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Ann M Manzardo
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
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Rethmeyer JA, Tan X, Manzardo A, Schroeder SR, Butler MG. Comparison of biological specimens and DNA collection methods for PCR amplification and microarray analysis. Clin Chem Lab Med 2014; 51:e79-83. [PMID: 23241593 DOI: 10.1515/cclm-2012-0429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 11/07/2012] [Indexed: 11/15/2022]
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Harrington RA, Weinstein DA, Miller JL. Hypoglycemia in Prader-Willi syndrome. Am J Med Genet A 2014; 164A:1127-9. [PMID: 24458695 DOI: 10.1002/ajmg.a.36405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 11/27/2013] [Indexed: 11/06/2022]
Abstract
Although mouse models of Prader-Willi syndrome (PWS) suggest that hypoglycemia may be part of this syndrome, review of the literature shows little evidence that it is an issue in humans with PWS. Both adrenal and growth hormone deficiency can be seen in PWS, and both of these hormone deficiencies are associated with increased risk for hypoglycemia. We reviewed medical records for patients with PWS seen at the University of Florida Prader-Willi Program. Children were 2 months to 5 years of age. We recorded the presence, degree, and persistence of hypoglycemia, age of first occurrence, genetic diagnosis, and gestational age. Repeated hypoglycemia was determined if individuals had multiple blood glucose (BG) values <50 mg/dl before 1 month old, or BG levels <50 mg/dl once and additional BG values <70 mg/dl after 1 year of age. Of 95 patient charts reviewed, 12 (12.6%) had recorded hypoglycemia. Six of 12 patients with hypoglycemia had documented BG levels <40 mg/dl. Seven had their first episode of hypoglycemia within the first day of life. Of these seven individuals, five had BG <40 mg/dl. Repeated hypoglycemia was noted in 10 patients (83% of all patients with hypoglycemia). Only two with hypoglycemia had documented adrenal insufficiency. Our study suggests that infants with PWS may be predisposed to hypoglycemia from birth. Additional investigation is necessary to confirm our findings and define the cause of hypoglycemia. If the presence of hypoglycemia is confirmed, early detection and treatment may result in improved neurocognitive outcomes.
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Affiliation(s)
- Rena A Harrington
- Pediatric Endocrinology, University of Florida, Gainesville, Florida
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Detection of chromosomal imbalances using combined MLPA kits in patients with syndromic intellectual disability. REV ROMANA MED LAB 2014. [DOI: 10.2478/rrlm-2014-0019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Miller JL, Linville TD, Dykens EM. Effects of metformin in children and adolescents with Prader-Willi syndrome and early-onset morbid obesity: a pilot study. J Pediatr Endocrinol Metab 2014; 27:23-9. [PMID: 23893676 PMCID: PMC3864175 DOI: 10.1515/jpem-2013-0116] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/03/2013] [Indexed: 12/14/2022]
Abstract
Prader-Willi syndrome (PWS) is one of the most commonly recognized causes of early-onset childhood obesity. Individuals with PWS have significant hyperphagia and decreased recognition of satiety. The exact etiology of the hyperphagia remains unknown and, therefore, untreatable. We conducted a pilot, open-label study of response to metformin in 21 children with PWS and six with early morbid obesity (EMO). Participants had significant insulin resistance and glucose intolerance on oral glucose tolerance testing (OGTT) and were started on metformin for these biochemical findings. We administered the Hyperphagia Questionnaire to parents of patients before and after starting metformin treatment. Both the PWS and EMO groups showed significant improvements in food-related distress, anxiety, and ability to be redirected away from food on the Hyperphagia Questionnaire. In the PWS group, improvements were predominantly seen in females. Within the PWS group, responders to metformin had higher 2-h glucose levels on OGTT (7.48 mmol/L vs. 4.235 mmol/L; p=0.003) and higher fasting insulin levels (116 pmol/L vs. 53.5 pmol/L; p=0.04). Additionally, parents of 5/13 individuals with PWS and 5/6 with EMO reported that their child was able to feel full while on metformin (for many this was the first time they had ever described a feeling of fullness). Metformin may improve sense of satiety and decrease anxiety about food in some individuals with PWS and EMO. Positive response to metformin may depend on the degree of hyperinsulinism and glucose intolerance. Nonetheless, the results of this pilot study bear further investigation.
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Miller JL, Angulo M. An open-label pilot study of N-acetylcysteine for skin-picking in Prader-Willi syndrome. Am J Med Genet A 2013; 164A:421-4. [PMID: 24311388 DOI: 10.1002/ajmg.a.36306] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 09/26/2013] [Indexed: 12/22/2022]
Abstract
Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by an abnormality on the long arm of chromosome 15 (q11-q13) that results in a host of behavioral characteristics including excessive interest in food, skin picking, difficulty with a change in routine, and obsessive and compulsive behaviors. Skin-picking can result in serious and potentially life-threatening infections. Recent evidence suggests that the excitatory neurotransmitter glutamate is dysregulated in obsessive-compulsive behaviors, and modulation of the glutaminergic pathway may decrease compulsive behaviors, such as recurrent hair pulling or skin-picking behaviors. N-acetylcysteine (NAC), a derivative of the amino acid cysteine, is thought to act either via modulation of NMDA glutamate receptors or by increasing glutathione in pilot studies. Thirty-five individuals with confirmed PWS (ages 5-39 years, 23 females/12 males) and skin-picking behavior for more than 1 year were treated with N-acetylcysteine (Pharma-NAC®) at a dose of 450-1,200 mg/day. Skin-picking symptoms and open lesions were assessed after 12 weeks of treatment by counting and measuring lesions before and after the medication. All 35 individuals had improvement in skin-picking behaviors. Ten (29%) individuals (six males and four females) did not have complete resolution of skin-picking behavior, but had significant reduction in the number of active lesions. Longer-term, placebo-controlled trials are needed to further assess the potential benefit of this treatment.
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Affiliation(s)
- Jennifer L Miller
- Department of Pediatrics-Endocrinology, University of Florida, Gainsville, Florida
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Anderlid BM, Lundin J, Malmgren H, Lehtihet M, Nordgren A. Small mosaic deletion encompassing the snoRNAs and SNURF-SNRPN results in an atypical Prader-Willi syndrome phenotype. Am J Med Genet A 2013; 164A:425-31. [PMID: 24311433 DOI: 10.1002/ajmg.a.36307] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 09/29/2013] [Indexed: 11/06/2022]
Abstract
Genetic analyses were performed in a male patient with suspected Prader-Willi syndrome who presented with hypogonadism, excessive eating, central obesity, small hands and feet and cognition within the low normal range. However, he had no neonatal hypotonia or feeding problems during infancy. Chromosome analysis showed a normal male karyotype. Further analysis with array-CGH identified a mosaic 847 kb deletion in 15q11-q13, including SNURF-SNRPN, the snoRNA gene clusters SNORD116 (HBII-85), SNORD115, (HBII-52), SNORD109 A and B (HBII-438A and B), SNORD64 (HBII-13), and NPAP1 (C15ORF2). MLPA confirmed the deletion and the results were compatible with a paternal origin. Metaphase-FISH verified the mosaicism with the deletion present in 58% of leukocytes analyzed. Three smaller deletions in this region have previously been reported in patients with Prader-Willi syndrome phenotype. All three deletions included SNORD116, but only two encompassed parts of SNURF-SNRPN, implicating SNORD116 as the major contributor to the Prader-Willi phenotype. Our case adds further information about genotype-phenotype correlation and supports the hypothesis that SNORD116 plays a major role in the pathogenesis of Prader-Willi syndrome. Furthermore, it examplifies diagnostic difficulties in atypical cases and illustrates the need for additional testing methods when Prader-Willi syndrome is suspected.
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Affiliation(s)
- Britt-Marie Anderlid
- Department of Molecular Medicine and Surgery, Clinal Genetic Unit, Centre of Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
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Gong X, Wu X, Ma X, Wu D, Zhang T, He L, Qin S, Li X. Microdeletion and microduplication analysis of chinese conotruncal defects patients with targeted array comparative genomic hybridization. PLoS One 2013; 8:e76314. [PMID: 24098474 PMCID: PMC3788710 DOI: 10.1371/journal.pone.0076314] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 08/23/2013] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE The current study aimed to develop a reliable targeted array comparative genomic hybridization (aCGH) to detect microdeletions and microduplications in congenital conotruncal defects (CTDs), especially on 22q11.2 region, and for some other chromosomal aberrations, such as 5p15-5p, 7q11.23 and 4p16.3. METHODS Twenty-seven patients with CTDs, including 12 pulmonary atresia (PA), 10 double-outlet right ventricle (DORV), 3 transposition of great arteries (TGA), 1 tetralogy of Fallot (TOF) and one ventricular septal defect (VSD), were enrolled in this study and screened for pathogenic copy number variations (CNVs), using Agilent 8 x 15K targeted aCGH. Real-time quantitative polymerase chain reaction (qPCR) was performed to test the molecular results of targeted aCGH. RESULTS Four of 27 patients (14.8%) had 22q11.2 CNVs, 1 microdeletion and 3 microduplications. qPCR test confirmed the microdeletion and microduplication detected by the targeted aCGH. CONCLUSION Chromosomal abnormalities were a well-known cause of multiple congenital anomalies (MCA). This aCGH using arrays with high-density coverage in the targeted regions can detect genomic imbalances including 22q11.2 and other 10 kinds CNVs effectively and quickly. This approach has the potential to be applied to detect aneuploidy and common microdeletion/microduplication syndromes on a single microarray.
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Affiliation(s)
- Xiaohui Gong
- Obstetrics and Gynecology Hospital of Shanghai Fudan University, the Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China
| | - Xi Wu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Xiaojing Ma
- Pediatric Hospital, Shanghai Fudan University, Shanghai, China
| | - Dandan Wu
- Ninth People’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ting Zhang
- Capital Institute of Pediatrics, Beijing, Chaoyang District, Beijing , China
| | - Li He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Shengying Qin
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Xiaotian Li
- Obstetrics and Gynecology Hospital of Shanghai Fudan University, the Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China
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Abstract
Prader-Willi Syndrome is a complex neurogenetic disorder characterized by appetite dysregulation, obesity with decreased muscle mass and increased fat mass, behavioral problems, various endocrinopathies, and sleep and respiratory abnormalities. Respiratory issues include both central and obstructive sleep apnea, excessive daytime sleepiness, narcolepsy, and impaired ventilatory control. There is some controversy as to whether growth hormone treatment, which is the standard of care for patients with Prader-Willi Syndrome, exacerbates or ameliorates the sleep-disordered breathing issues associated with this syndrome. The natural history of sleep and breathing issues and the issues surrounding growth hormone treatment on sleep-disordered breathing are discussed.
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Mertz LGB, Christensen R, Vogel I, Hertz JM, Nielsen KB, Grønskov K, Østergaard JR. Angelman syndrome in Denmark. birth incidence, genetic findings, and age at diagnosis. Am J Med Genet A 2013; 161A:2197-203. [PMID: 23913711 DOI: 10.1002/ajmg.a.36058] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/07/2012] [Accepted: 04/20/2013] [Indexed: 11/09/2022]
Abstract
Angelman syndrome (AS) is a neurogenetic disorder caused by loss of expression of the maternal imprinted gene UBE3A on chromosome 15q11.2-q13. Clinical features of AS include severe intellectual disability, a happy disposition, ataxia, mandibular prognatism, and epilepsy. Our objectives were to examine the birth incidence of AS in Denmark and to characterize the size of the 15q11.2-q13 deletions with 1,000K array CGH. In addition, we analyzed genotype differences in regard to age at diagnosis and investigated the occurrence of deletions/duplications outside the 15q11.2-q13 regions. We identified 51 patients with genetically verified AS, which corresponded to a birth incidence of 1:24,580 (95%CI: 1:23,727-1:25,433). Thirty-six patients showed a deletion; 13 had a Class I deletion and 20 had a Class II deletion. There was bimodal distribution of the BP3 breakpoint. Three patients had larger and atypical deletions, with distal breakpoints telomeric to BP3. Five patients had paternal uniparental disomy (pUPD) of chromosome 15, and four had a verified UBE3A mutation. Additional deletions/duplications outside the 15q11.2-q13 areas were demonstrated in half the participants. Six harbored more than one CNV. Mean age at diagnosis was 21 months (95%CI: 17-23 months) for children with a deletion and 46 months (95%CI: 36-55 months) for children with pUPD or a UBE3A mutation (P < 0.01). The presence of a CNV outside 15q11.2-q13 did not have an impact on age at diagnosis.
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Affiliation(s)
- Line Granild Bie Mertz
- Department of Pediatrics, Center for Rare Diseases, Aarhus University Hospital, Aarhus, Denmark.
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Abstract
The autism spectrum disorders (ASD) are characterized by impairments in social interaction and stereotyped behaviors. For the majority of individuals with ASD, the causes of the disorder remain unknown; however, in up to 25% of cases, a genetic cause can be identified. Chromosomal rearrangements as well as rare and de novo copy-number variants are present in ∼10-20% of individuals with ASD, compared with 1-2% in the general population and/or unaffected siblings. Rare and de novo coding-sequence mutations affecting neuronal genes have also been identified in ∼5-10% of individuals with ASD. Common variants such as single-nucleotide polymorphisms seem to contribute to ASD susceptibility, but, taken individually, their effects appear to be small. Despite a heterogeneous genetic landscape, the genes implicated thus far-which are involved in chromatin remodeling, metabolism, mRNA translation, and synaptic function-seem to converge in common pathways affecting neuronal and synaptic homeostasis. Animal models developed to study these genes should lead to a better understanding of the diversity of the genetic landscapes of ASD.
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Affiliation(s)
- Guillaume Huguet
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, 75015 Paris, France;
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Butler MG, Roberts J, Hayes J, Tan X, Manzardo AM. Growth hormone receptor (GHR) gene polymorphism and Prader-Willi syndrome. Am J Med Genet A 2013; 161A:1647-53. [PMID: 23696513 DOI: 10.1002/ajmg.a.35980] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/24/2013] [Indexed: 02/03/2023]
Abstract
Prader-Willi syndrome (PWS) is a genomic imprinting disorder due to loss of paternally expressed genes in the 15q11-q13 region and characterized by hypotonia, a poor suck, failure to thrive, hypogonadism/hypogenitalism, growth hormone deficiency, learning, and behavioral problems and hyperphagia leading to early childhood obesity. Growth hormone acts as a ligand for the growth hormone receptor (GHR) coded by a gene polymorphic for an exon-3 deletion (d3) seen in about 50% of Caucasians and associated with an increased response to growth hormone (GH) therapy. We examined 69 individuals with PWS (average age ± SD = 20.1 ± 12.8 year). The GHR allele distribution in our PWS subjects was similar to reported data in the literature with no gender or PWS genetic subtype differences. A negative correlation was found with age for height standard deviational scores and a positive correlation with age for weight and BMI for non-GH treated PWS subjects. Adjusting for effects of age and gender, individuals with PWS and the d3/d3 allele showed a significant increase in BMI compared with those having the full length (fl) allele. In addition, 12 infants and children with PWS were examined when growth and GH data were available before and during GH treatment. A significant increase in growth rate (1.7 times) was noted in the presence of the d3 allele (fl/fl = 0.87 cm/month; fl/d3 or d3/d3 = 1.5 cm/month; P < 0.05). The presence of the d3 allele and its impact on growth and medical care of individuals with PWS while on GH therapy should be further investigated.
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Affiliation(s)
- Merlin G Butler
- Department of Psychiatry and Behavioral Sciences, Kansas University Medical Center, Kansas City, KS 66160, USA.
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Liu APY, Tang WF, Lau ET, Chan KYK, Kan ASY, Wong KY, Tso WWY, Jalal K, Lee SL, Chau CSK, Chung BHY. Expanded Prader-Willi syndrome due to chromosome 15q11.2-14 deletion: report and a review of literature. Am J Med Genet A 2013; 161A:1309-18. [PMID: 23633107 DOI: 10.1002/ajmg.a.35909] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 01/25/2013] [Indexed: 11/08/2022]
Abstract
We report on a male infant with de novo unbalanced t(5;15) translocation resulting in a 17.23 Mb deletion within 15q11.2-q14 and a 25.12 kb deletion in 5pter. The 15q11.2-q14 deletion encompassed the 15q11.2-q13 Prader-Willi syndrome (PWS) critical region and the recently described 15q13.3 microdeletion syndrome region while the 5pter deletion contained no RefSeq genes. From our literature review, patients with similar deletions in chromosome 15q exhibit expanded phenotype of severe developmental delay, protracted feeding problem, absent speech, central visual impairment, congenital malformations and epilepsy in addition to those typical of PWS. The patient reported herein had previously unreported anomalies of mega cisterna magna, horseshoe kidney and the rare neonatal interstitial lung disease known as pulmonary interstitial glycogenosis. Precise breakpoint delineation by microarray is useful in patients with atypical PWS deletions to guide investigation and prognostication.
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Affiliation(s)
- Anthony P Y Liu
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, and Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
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Miller JL, Lynn CH, Shuster J, Driscoll DJ. A reduced-energy intake, well-balanced diet improves weight control in children with Prader-Willi syndrome. J Hum Nutr Diet 2012; 26:2-9. [PMID: 23078343 DOI: 10.1111/j.1365-277x.2012.01275.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Children with Prader-Willi syndrome (PWS) have a predictable pattern of weight gain, with obesity beginning in early childhood and worsening as they get older and hyperphagia increases. Data on the most effective dietary modifications are scant and primarily anecdotal. As part of a longitudinal study investigating the natural history of PWS, we evaluated the effect of a well-balanced, energy-restricted diet on body composition and weight in young children with PWS. METHODS Sixty-three children, aged 2-10 years, with genetically proven PWS participated in the present study. These children had measurements of body composition by dual-energy X-ray absorptiometry and resting energy expenditure (REE), as well as a 3-day diet history analysis both before and after intervention. Energy calculations were based on the individual's REE, with the recommendation that the macronutrients of the diet consist of 30% fat, 45% carbohydrates and 25% protein, with at least 20 g of fibre per day. RESULTS Thirty-three families adhered to our dietary recommendations for both energy intake and macronutrient distribution. Those 33 children had lower body fat (19.8% versus 41.9%; P < 0.001) and weight management (body mass index SD score 0.3 versus 2.23; P < 0.001) than those whose parents followed the energy intake recommendations but did not alter the macronutrient composition of the diet. Those who followed our recommendations also had a lower respiratory quotient (0.84 versus 0.95; P = 0.002). CONCLUSIONS Our recommendation for an energy-restricted diet with a well-balanced macronutrient composition and fibre intake improves both weight and body composition in children with PWS compared to a simple energy-restricted diet.
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Affiliation(s)
- J L Miller
- University of Florida, Department of Pediatrics, Gainesville, FL 32608, USA.
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Rosenbloom ST, Butler MG. Development and implementation of electronic growth charts for infants with Prader-Willi syndrome. Am J Med Genet A 2012; 158A:2743-9. [PMID: 22903930 DOI: 10.1002/ajmg.a.35581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Accepted: 06/23/2012] [Indexed: 11/09/2022]
Abstract
Pediatric growth charts are used to monitor children's growth and development, and assist in healthcare delivery and supervision. Researchers have developed syndrome-specific growth charts for several disorders in which affected children grow differently than unaffected children. Typical standardized growth curves have been recently reported in non-growth hormone treated infants with Prader-Willi syndrome (PWS) of both genders from birth to 36 months of age to support monitoring growth and nutritional status during infancy, and to guide growth hormone treatment and follow up. Electronic health record (EHR) systems serving pediatric populations can now incorporate interactive automated growth charts to assist the healthcare providers in clinical settings to monitor growth. The American Academy of Pediatrics has recommended that EHR systems incorporate syndrome-specific growth charts where feasible. This manuscript describes the experiences at two medical centers at different stages of incorporating electronic growth charts into the medical records on infants with rare disorders, using PWS as an illustration. The absence of readily available and accessible syndrome-specific standardized growth charts in other disorders causes challenges for EHR personnel and for healthcare providers who care for these children particularly in the growing electronic medical record environment.
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Affiliation(s)
- S Trent Rosenbloom
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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Jin DK. Endocrine problems in children with Prader-Willi syndrome: special review on associated genetic aspects and early growth hormone treatment. KOREAN JOURNAL OF PEDIATRICS 2012; 55:224-31. [PMID: 22844316 PMCID: PMC3405154 DOI: 10.3345/kjp.2012.55.7.224] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 05/07/2012] [Indexed: 11/27/2022]
Abstract
Prader-Willi syndrome (PWS) is a complex multisystem genetic disorder characterized by hypothalamic-pituitary dysfunction. The main clinical features include neonatal hypotonia, distinctive facial features, overall developmental delay, and poor growth in infancy, followed by overeating with severe obesity, short stature, and hypogonadism later in development. This paper reviews recent updates regarding the genetic aspects of this disorder. Three mechanisms (paternal deletion, maternal disomy, and deficient imprinting) are recognized. Maternal disomy can arise because of 4 possible mechanisms: trisomy rescue (TR), gamete complementation (GC), monosomy rescue (MR), and postfertilization mitotic nondisjunction (Mit). Recently, TR/GC caused by nondisjunction at maternal meiosis 1 has been identified increasingly, as a result of advanced maternal childbearing age in Korea. We verified that the d3 allele increases the responsiveness of the growth hormone (GH) receptor to endogenous GH. This paper also provides an overview of endocrine dysfunctions in children with PWS, including GH deficiency, obesity, sexual development, hypothyroidism, and adrenal insufficiency, as well as the effects of GH treatment. GH treatment coupled with a strictly controlled diet during early childhood may help to reduce obesity, improve neurodevelopment, and increase muscle mass. A more active approach to correct these hormone deficiencies would benefit patients with PWS.
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Affiliation(s)
- Dong-Kyu Jin
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Honea RA, Holsen LM, Lepping RJ, Perea R, Butler MG, Brooks WM, Savage CR. The neuroanatomy of genetic subtype differences in Prader-Willi syndrome. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:243-53. [PMID: 22241551 PMCID: PMC3296480 DOI: 10.1002/ajmg.b.32022] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Despite behavioral differences between genetic subtypes of Prader-Willi syndrome (PWS), no studies have been published characterizing brain structure in these subgroups. Our goal was to examine differences in the brain structure phenotype of common subtypes of PWS [chromosome 15q deletions and maternal uniparental disomy 15 (UPD)]. Fifteen individuals with PWS due to a typical deletion [(DEL) type I; n = 5, type II; n = 10], eight with PWS due to UPD, and 25 age-matched healthy-weight individuals (HWC) participated in structural magnetic resonance imaging (MRI) scans. A custom voxel-based morphometry processing stream was used to examine regional differences in gray and white matter volume (WMV) between groups, covarying for age, sex, and body mass index (BMI). Overall, compared to HWC, PWS individuals had lower gray matter volumes (GMV) that encompassed the prefrontal, orbitofrontal and temporal cortices, hippocampus and parahippocampal gyrus, and lower WMVs in the brain stem, cerebellum, medial temporal, and frontal cortex. Compared to UPD, the DEL subtypes had lower GMV primarily in the prefrontal and temporal cortices, and lower white matter in the parietal cortex. The UPD subtype had more extensive lower gray and WMVs in the orbitofrontal and limbic cortices compared to HWC. These preliminary findings are the first structural neuroimaging findings to support potentially separate neural mechanisms mediating the behavioral differences seen in these genetic subtypes.
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Affiliation(s)
- Robyn A Honea
- Department of Neurology, University of Kansas School of Medicine, Kansas City, USA
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Molina O, Anton E, Vidal F, Blanco J. High rates of de novo 15q11q13 inversions in human spermatozoa. Mol Cytogenet 2012; 5:11. [PMID: 22309495 PMCID: PMC3293048 DOI: 10.1186/1755-8166-5-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/06/2012] [Indexed: 11/22/2022] Open
Abstract
Low-Copy Repeats predispose the 15q11-q13 region to non-allelic homologous recombination. We have already demonstrated that a significant percentage of Prader-Willi syndrome (PWS) fathers have an increased susceptibility to generate 15q11q13 deletions in spermatozoa, suggesting the participation of intrachromatid exchanges. This work has been focused on assessing the incidence of de novo 15q11q13 inversions in spermatozoa of control donors and PWS fathers in order to determine the basal rates of inversions and to confirm the intrachromatid mechanism as the main cause of 15q11q13 anomalies. Semen samples from 10 control donors and 16 PWS fathers were processed and analyzed by triple-color FISH. Three differentially labeled BAC-clones were used: one proximal and two distal of the 15q11-q13 region. Signal associations allowed the discrimination between normal and inverted haplotypes, which were confirmed by laser-scanning confocal microscopy. Two types of inversions were detected which correspond to the segments involved in Class I and II PWS deletions. No significant differences were observed in the mean frequencies of inversions between controls and PWS fathers (3.59% ± 0.46 and 9.51% ± 0.87 vs 3.06% ± 0.33 and 10.07% ± 0.74). Individual comparisons showed significant increases of inversions in four PWS fathers (P < 0.05) previously reported as patients with increases of 15q11q13 deletions. Results suggest that the incidence of heterozygous inversion carriers in the general population could reach significant values. This situation could have important implications, as they have been described as predisposing haplotypes for genomic disorders. As a whole, results confirm the high instability of the 15q11-q13 region, which is prone to different types of de novo reorganizations by intrachromatid NAHR.
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Affiliation(s)
- Oscar Molina
- Unitat de Biologia Cel·lular (Facultat de Biociències), Universitat Autònoma de Barcelona, 08193-Bellaterra (Cerdanyola del Vallès), SPAIN.
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Rout U, Abdul-Rahman OA, Dhossche DM. An immunological basis of hyperphagia driven by GABAergic dysfunction in Prader-Willi Syndrome. Med Hypotheses 2012; 78:462-4. [PMID: 22289342 DOI: 10.1016/j.mehy.2011.12.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Accepted: 12/27/2011] [Indexed: 10/14/2022]
Abstract
Impaired immune function is increasingly seen as a core element of various neurological, psychiatric, and developmental disorders but has not yet been investigated in subjects with Prader-Willi Syndrome. We hypothesize that the emergence and the progression of PWS may be regulated by immune dysfunction involving auto-antibodies and miRNA driven by GABAergic dysfunction. Future research testing this hypothesis is discussed.
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Affiliation(s)
- Ujjwal Rout
- Department of Surgery, Physiology and Biophysics, The University of Mississippi Medical Center, Jackson, MS 39216-4505, USA.
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Melhem N, Middleton F, McFadden K, Klei L, Faraone SV, Vinogradov S, Tiobech J, Yano V, Kuartei S, Roeder K, Byerley W, Devlin B, Myles-Worsley M. Copy number variants for schizophrenia and related psychotic disorders in Oceanic Palau: risk and transmission in extended pedigrees. Biol Psychiatry 2011; 70:1115-21. [PMID: 21982423 PMCID: PMC3224197 DOI: 10.1016/j.biopsych.2011.08.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 07/08/2011] [Accepted: 08/02/2011] [Indexed: 12/31/2022]
Abstract
BACKGROUND We report on copy number variants (CNVs) found in Palauan subjects ascertained for schizophrenia and related psychotic disorders in extended pedigrees in Palau. We compare CNVs found in this Oceanic population with those seen in other samples, typically of European ancestry. Assessing CNVs in Palauan extended pedigrees yields insight into the evolution of risk CNVs, such as how they arise, are transmitted, and are lost from populations by stochastic or selective processes, none of which are easily measured from case-control samples. METHODS DNA samples from 197 subjects affected with schizophrenia and related psychotic disorders, 185 of their relatives, and 159 control subjects were successfully characterized for CNVs using Affymetrix Genomewide Human SNP Array 5.0. RESULTS Copy number variants thought to be associated with risk for schizophrenia and related disorders also occur in affected individuals in Palau, specifically 15q11.2 and 1q21.1 deletions, partial duplication of IL1RAPL1 (Xp21.3), and chromosome X duplications (Klinefelter's syndrome). Partial duplication within A2BP1 appears to convey an eightfold increased risk in male subjects (95% confidence interval, .8-84.4) but not female subjects (odds ratio = .4, 95% confidence interval, .03-4.9). Affected-only linkage analysis using this variant yields a logarithm of the odds score of 3.5. CONCLUSIONS This study reveals CNVs that confer risk to schizophrenia and related psychotic disorders in Palau, most of which have been previously observed in samples of European ancestry. Only a few of these CNVs show evidence that they have existed for many generations, consistent with risk variants diminishing reproductive success.
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Affiliation(s)
- Nadine Melhem
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Frank Middleton
- Department of Psychiatry, SUNY Upstate Medical University; Syracuse NY
| | - Kathryn McFadden
- Division of Neuropathology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Lambertus Klei
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Stephen V Faraone
- Department of Psychiatry, SUNY Upstate Medical University; Syracuse NY
| | - Sophia Vinogradov
- Department of Psychiatry, University of California San Francisco, Pittsburgh, PA
| | - Josepha Tiobech
- Palauan Ministry of Health, Republic of Palau, Pittsburgh, PA
| | - Victor Yano
- Palauan Ministry of Health, Republic of Palau, Pittsburgh, PA
| | | | - Kathryn Roeder
- Department of Statistics, Carnegie Mellon University, Pittsburgh, PA
| | - William Byerley
- Department of Psychiatry, University of California San Francisco, Pittsburgh, PA
| | - Bernie Devlin
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA
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43
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Unique and atypical deletions in Prader-Willi syndrome reveal distinct phenotypes. Eur J Hum Genet 2011; 20:283-90. [PMID: 22045295 DOI: 10.1038/ejhg.2011.187] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a multisystem, contiguous gene disorder caused by an absence of paternally expressed genes within the 15q11.2-q13 region via one of the three main genetic mechanisms: deletion of the paternally inherited 15q11.2-q13 region, maternal uniparental disomy and imprinting defect. The deletion class is typically subdivided into Type 1 and Type 2 based on their proximal breakpoints (BP1-BP3 and BP2-BP3, respectively). Despite PWS being a well-characterized genetic disorder the role of the specific genes contributing to various aspects of the phenotype are not well understood. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) is a recently developed technique that detects copy number changes and aberrant DNA methylation. In this study, we initially applied MS-MLPA to elucidate the deletion subtypes of 88 subjects. In our cohort, 32 had a Type 1 and 49 had a Type 2 deletion. The remaining seven subjects had unique or atypical deletions that were either smaller (n=5) or larger (n=2) than typically described and were further characterized by array-based comparative genome hybridization. In two subjects both the PWS region (15q11.2) and the newly described 15q13.3 microdeletion syndrome region were deleted. The subjects with a unique or an atypical deletion revealed distinct phenotypic features. In conclusion, unique or atypical deletions were found in ∼8% of the deletion subjects with PWS in our cohort. These novel deletions provide further insight into the potential role of several of the genes within the 15q11.2 and the 15q13.3 regions.
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Henkhaus RS, Kim SJ, Kimonis VE, Gold JA, Dykens EM, Driscoll DJ, Butler MG. Methylation-specific multiplex ligation-dependent probe amplification and identification of deletion genetic subtypes in Prader-Willi syndrome. Genet Test Mol Biomarkers 2011; 16:178-86. [PMID: 21977908 DOI: 10.1089/gtmb.2011.0115] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are complex neurodevelopmental disorders caused by loss of expression of imprinted genes from the 15q11-q13 region depending on the parent of origin. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) kits from MRC-Holland (Amsterdam, The Netherlands) were used to detect PWS and AS deletion subtypes. We report our experience with two versions of the MS-MLPA-PWS/AS kit (original A1 and newer B1) in determining methylation status and deletion subtypes in individuals with PWS. METHODS MS-MLPA analysis was performed on DNA isolated from a large cohort of PWS subjects with the MS-MLPA-PWS/AS-A1 and -B1 probe sets. RESULTS Both MS-MLPA kits will identify deletions in the 15q11-q13 region but the original MS-MLPA-A1 kit has a higher density of probes at the telomeric end of the 15q11-q13 region, which is more useful for identifying individuals with atypical deletions. The newer B1 kit contains more probes in the imprinting center (IC) and adjoining small noncoding RNAs useful in identifying small microdeletions. CONCLUSION The A1 kit identified the typical deletions and smaller atypical deletions, whereas the B1 kit was more informative for identifying microdeletions including the IC and SNORD116 regions. Both kits should be made available for accurate characterization of PWS/AS deletion subtypes as well as evaluating for IC and SNORD116 microdeletions.
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Affiliation(s)
- Rebecca S Henkhaus
- Department of Psychiatry and Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Khan WA, Knoll JHM, Rogan PK. Context-based FISH localization of genomic rearrangements within chromosome 15q11.2q13 duplicons. Mol Cytogenet 2011; 4:15. [PMID: 21824424 PMCID: PMC3171312 DOI: 10.1186/1755-8166-4-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 08/08/2011] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Segmental duplicons (SDs) predispose to an increased frequency of chromosomal rearrangements. These rearrangements can cause a diverse range of phenotypes due to haploinsufficiency, in cis positional effects or gene interruption. Genomic microarray analysis has revealed gene dosage changes adjacent to duplicons, but the high degree of similarity between duplicon sequences has confounded unequivocal assignment of chromosome breakpoints within these intervals. In this study, we localize rearrangements within duplicon-enriched regions of Angelman/Prader-Willi (AS/PWS) syndrome chromosomal deletions with fluorescence in situ hybridization (FISH). RESULTS Breakage intervals in AS deletions were localized recursively with short, coordinate-defined, single copy (SC) and low copy (LC) genomic FISH probes. These probes were initially coincident with duplicons and regions of previously reported breakage in AS/PWS. Subsequently, probes developed from adjacent genomic intervals more precisely delineated deletion breakage intervals involving genes, pseudogenes and duplicons in 15q11.2q13. The observed variability in the deletion boundaries within previously described Class I and Class II deletion AS samples is related to the local genomic architecture in this chromosomal region. CONCLUSIONS Chromosome 15 abnormalities associated with SDs were precisely delineated at a resolution equivalent to genomic Southern analysis. This context-dependent approach can define the boundaries of chromosome rearrangements for other genomic disorders associated with SDs.
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Affiliation(s)
- Wahab A Khan
- Department of Biochemistry, University of Western Ontario, Laboratories of Genome Bioinformatics and Genomic Disorders, 1151 Richmond Street, London, ON, Canada
- Department of Pathology, University of Western Ontario, Laboratories of Genome Bioinformatics and Genomic Disorders, 1151 Richmond Street, London, ON, Canada
| | - Joan HM Knoll
- Department of Pathology, University of Western Ontario, Laboratories of Genome Bioinformatics and Genomic Disorders, 1151 Richmond Street, London, ON, Canada
| | - Peter K Rogan
- Department of Biochemistry, University of Western Ontario, Laboratories of Genome Bioinformatics and Genomic Disorders, 1151 Richmond Street, London, ON, Canada
- Department of Computer Science, University of Western Ontario, Laboratories of Genome Bioinformatics and Genomic Disorders, 1151 Richmond Street, London, ON, Canada
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Chen Y, Liu YJ, Pei YF, Yang TL, Deng FY, Liu XG, Li DY, Deng HW. Copy number variations at the Prader-Willi syndrome region on chromosome 15 and associations with obesity in whites. Obesity (Silver Spring) 2011; 19:1229-34. [PMID: 21233802 PMCID: PMC4512297 DOI: 10.1038/oby.2010.323] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Obesity is a serious health problem with strong genetic determination. Copy number variation (CNV) is a common type of genomic variant associated with some complex human diseases. However, it is not clear how CNVs contribute to the etiology of obesity. In this study, we examined 1,000 unrelated US whites to search for CNVs that may predispose to obesity. We focused our analyses on the Prader-Willi syndrome (PWS) critical region (chromosome 15q11-q13), because the PWS region is a hotspot for CNV generation and obesity is one of the major clinical manifestations for chromosome abnormalities at this region. We constructed a map containing 39 CNVs at the PWS critical region with CNV occurrence rates higher than 1%. Among them, three CNVs were significantly associated with body fat mass (P < 0.05), with a higher copy number (CN) associated with an increase of 5.08-9.77 kg in body fat mass. These three CNVs are close to two known PWS genes, NDN (necdin homolog) and C15orf2 (chromosome 15 open reading frame 2), and partially overlap with another obesity gene PWRN1 (Prader-Willi region nonprotein-coding RNA 1). Interestingly, our recently published whole genome association scan study using the same sample by examining single-nucleotide polymorphisms (SNPs) did not find any significant associations at these CNV regions, suggesting the importance of examining both CNVs and SNPs for better understanding of genetic basis of obesity. Further studies are warranted to validate these CNVs and their importance to obesity.
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Affiliation(s)
- Yuan Chen
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education and Institute of Molecular Genetics, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, The People’s Republic of China
| | - Yong-Jun Liu
- School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Yu-Fang Pei
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education and Institute of Molecular Genetics, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, The People’s Republic of China
- School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Tie-Lin Yang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education and Institute of Molecular Genetics, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, The People’s Republic of China
- School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Fei-Yan Deng
- School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Xiao-Gang Liu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education and Institute of Molecular Genetics, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, The People’s Republic of China
| | - Ding-You Li
- Department of Pediatrics, Children’s Mercy Hospital, Kansas City, Missouri, USA
| | - Hong-Wen Deng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education and Institute of Molecular Genetics, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, The People’s Republic of China
- School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
- Center of System Biomedical Sciences, Shanghai University of Science and Technology, Shanghai, The People’s Republic of China
- College of Life Sciences and Engineering, Beijing Jiao Tong University, Beijing, The People’s Republic of China
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Butler MG. Prader-Willi Syndrome: Obesity due to Genomic Imprinting. Curr Genomics 2011; 12:204-15. [PMID: 22043168 PMCID: PMC3137005 DOI: 10.2174/138920211795677877] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/01/2011] [Accepted: 03/01/2011] [Indexed: 11/22/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder due to errors in genomic imprinting with loss of imprinted genes that are paternally expressed from the chromosome 15q11-q13 region. Approximately 70% of individuals with PWS have a de novo deletion of the paternally derived 15q11-q13 region in which there are two subtypes (i.e., larger Type I or smaller Type II), maternal disomy 15 (both 15s from the mother) in about 25% of cases, and the remaining subjects have either defects in the imprinting center controlling the activity of imprinted genes or due to other chromosome 15 rearrangements. PWS is characterized by a particular facial appearance, infantile hypotonia, a poor suck and feeding difficulties, hypogonadism and hypogenitalism in both sexes, short stature and small hands and feet due to growth hormone deficiency, mild learning and behavioral problems (e.g., skin picking, temper tantrums) and hyperphagia leading to early childhood obesity. Obesity is a significant health problem, if uncontrolled. PWS is considered the most common known genetic cause of morbid obesity in children. The chromosome 15q11-q13 region contains approximately 100 genes and transcripts in which about 10 are imprinted and paternally expressed. This region can be divided into four groups: 1) a proximal non-imprinted region; 2) a PWS paternal-only expressed region containing protein-coding and non-coding genes; 3) an Angelman syndrome region containing maternally expressed genes and 4) a distal non-imprinted region. This review summarizes the current understanding of the genetic causes, the natural history and clinical presentation of individuals with PWS.
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Affiliation(s)
- Merlin G Butler
- Departments of Psychiatry & Behavioral Sciences and Pediatrics, Kansas University Medical Center, Kansas City, Kansas, USA
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Sempere Pérez A, Manchón Trives I, Palazón Azorín I, Alcaraz Más L, Pérez Lledó E, Galán Sánchez F. [15Q11.2 (BP1-BP2) microdeletion, a new syndrome with variable expressivity]. An Pediatr (Barc) 2011; 75:58-62. [PMID: 21419731 DOI: 10.1016/j.anpedi.2011.01.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 01/31/2011] [Indexed: 11/19/2022] Open
Abstract
The case of a boy with psychomotor retardation and dysmorphic features is presented. He has a 1.5 Mb 15q11.2 microdeletion of paternal origin diagnosed by aCGH. The deletion is located between breakpoints BP1 and BP2 of the Prader-Willi/Angelman syndromes critical region. Clinical features in our patient fit well with those described in ten cases of pure BP1-BP2 deletion published to date.
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Affiliation(s)
- A Sempere Pérez
- Neuropediatría, Hospital General Universitario, Alicante, España
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Jin DK. Systematic review of the clinical and genetic aspects of Prader-Willi syndrome. KOREAN JOURNAL OF PEDIATRICS 2011; 54:55-63. [PMID: 21503198 PMCID: PMC3077502 DOI: 10.3345/kjp.2011.54.2.55] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 01/31/2011] [Indexed: 01/20/2023]
Abstract
Prader-Willi syndrome (PWS) is a complex multisystem genetic disorder that is caused by the lack of expression of paternally inherited imprinted genes on chromosome 15q11-q13. This syndrome has a characteristic phenotype including severe neonatal hypotonia, early-onset hyperphagia, development of morbid obesity, short stature, hypogonadism, learning disabilities, behavioral problems, and psychiatric problems. PWS is an example of a genetic condition caused by genomic imprinting. It can occur via 3 main mechanisms that lead to the absence of expression of paternally inherited genes in the 15q11.2-q13 region: paternal microdeletion, maternal uniparental disomy, and an imprinting defect. Over 99% of PWS cases can be diagnosed using DNA methylation analysis. Early diagnosis of PWS is important for effective long-term management. Growth hormone (GH) treatment improves the growth, physical phenotype, and body composition of patients with PWS. In recent years, GH treatment in infants has been shown to have beneficial effects on the growth and neurological development of patients diagnosed during infancy. There is a clear need for an integrated multidisciplinary approach to facilitate early diagnosis and optimize management to improve quality of life, prevent complications, and prolong life expectancy in patients with PWS.
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Affiliation(s)
- Dong Kyu Jin
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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50
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Hou A, Lin SP, Ho SY, Chen CFJ, Lin HY, Chen YJ, Huang CY, Chiu HC, Chuang CK, Chen KS. Genetic studies of Prader-Willi patients provide evidence for conservation of genomic architecture in proximal chromosome 15q. Ann Hum Genet 2011; 75:211-21. [PMID: 21198515 DOI: 10.1111/j.1469-1809.2010.00633.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Prader-Willi syndrome (PWS) is a neurogenetic disorder associated with recurrent genomic recombination involving low copy repeats (LCRs) located in the human chromosome 15q11-q13. Previous studies of PWS patients from Asia suggested that there is a higher incidence of deletion and lower incidence of maternal uniparental disomy (mUPD) compared to that of Western populations. In this report, we present genetic etiology of 28 PWS patients from Taiwan. Consistent with the genetic etiology findings from Western populations, the type II deletion appears to be the most common deletion subtype. Furthermore, the ratio of the two most common deletion subtypes and the ratio of the maternal heterodisomy to isodisomy cases observed from this study are in agreement with previous findings from Western populations. In addition, we identified and further mapped the deletion breakpoints in two patients with atypical deletions using array CGH (comparative genomic hybridization). Despite the relatively small numbers of patients in each subgroup, our findings suggest that the genomic architecture responsible for the recurrent recombination in PWS is conserved in Taiwanese of the Han Chinese heritage and Western populations, thereby predisposing chromosome 15q11-q13 to a similar risk of rearrangements.
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Affiliation(s)
- Aihua Hou
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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