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Schlaich E, Hubens WHG, Eggermann T. First-time application of droplet digital PCR for methylation testing of the 11p15.5 imprinting regions. Mol Genet Genomic Med 2023; 11:e2264. [PMID: 37519217 PMCID: PMC10724498 DOI: 10.1002/mgg3.2264] [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: 04/20/2023] [Revised: 06/20/2023] [Accepted: 07/20/2023] [Indexed: 08/01/2023] Open
Abstract
BACKGROUND Beckwith-Wiedemann syndrome and Silver-Russel syndrome are two imprinting disorders caused by opposite molecular alterations in 11p15.5. With the current diagnostic tests, their molecular diagnosis is challenging due to molecular heterogeneity and mosaic occurrence of the most frequent alterations. As the determination of precise (epi)genotype of patients is relevant as the basis for a personalized treatment, different approaches are needed to increase the sensitivity of diagnostic testing of imprinting disorders. METHODS We established methylation-specific droplet digital PCR approaches (MS-ddPCR) for the two imprinting centers in 11p15.5, and analyzed patients with paternal uniparental disomy of chromosome 11p15.5 (upd(11)pat) and other imprinting defects in the region. The results were compared to those from MS-MLPA (multiplex ligation-dependent probe amplification) and MS-pyrosequencing. RESULTS MS-ddPCR confirmed the molecular alterations in all patients and the results matched well with MS-MLPA. The results of MS-pyrosequencing varied between different runs, whereas MS-ddPCR results were reproducible. CONCLUSION We show for the first time that MS-ddPCR is a reliable and easy applicable method for determination of MS-associated changes in imprinting disorders. It is therefore an additional tool for multimethod diagnostics of imprinting disorders suitable to improve the diagnostic yield.
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Affiliation(s)
- Elia Schlaich
- Institute for Human Genetics and Genome Medicine, Medical Faculty, RWTH Aachen UniversityAachenGermany
| | - Wouter H. G. Hubens
- Institute for Stem Cell Biology, Medical Faculty, RWTH Aachen UniversityAachenGermany
- Helmholtz Institute for Biomedical Engineering, RWTH Aachen UniversityAachenGermany
| | - Thomas Eggermann
- Institute for Human Genetics and Genome Medicine, Medical Faculty, RWTH Aachen UniversityAachenGermany
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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: 5] [Impact Index Per Article: 2.5] [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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Butler MG, Miller BS, Romano A, Ross J, Abuzzahab MJ, Backeljauw P, Bamba V, Bhangoo A, Mauras N, Geffner M. Genetic conditions of short stature: A review of three classic examples. Front Endocrinol (Lausanne) 2022; 13:1011960. [PMID: 36339399 PMCID: PMC9634554 DOI: 10.3389/fendo.2022.1011960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/20/2022] [Indexed: 11/30/2022] Open
Abstract
Noonan, Turner, and Prader-Willi syndromes are classical genetic disorders that are marked by short stature. Each disorder has been recognized for several decades and is backed by extensive published literature describing its features, genetic origins, and optimal treatment strategies. These disorders are accompanied by a multitude of comorbidities, including cardiovascular issues, endocrinopathies, and infertility. Diagnostic delays, syndrome-associated comorbidities, and inefficient communication among the members of a patient's health care team can affect a patient's well-being from birth through adulthood. Insufficient information is available to help patients and their multidisciplinary team of providers transition from pediatric to adult health care systems. The aim of this review is to summarize the clinical features and genetics associated with each syndrome, describe best practices for diagnosis and treatment, and emphasize the importance of multidisciplinary teams and appropriate care plans for the pediatric to adult health care transition.
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Affiliation(s)
- Merlin G. Butler
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, United States
- Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States
- *Correspondence: Merlin G. Butler,
| | - Bradley S. Miller
- Pediatric Endocrinology, University of Minnesota Masonic Children’s Hospital, Minneapolis, MN, United States
| | - Alicia Romano
- Department of Pediatrics, New York Medical College, Valhalla, NY, United States
| | - Judith Ross
- Department of Pediatrics, Nemours Children’s Health, Wilmington, DE, United States
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, United States
| | | | - Philippe Backeljauw
- Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Vaneeta Bamba
- Division of Endocrinology, Children’s Hospital of Philadelphia; Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Amrit Bhangoo
- Pediatric Endocrinology, Children's Health of Orange County (CHOC) Children’s Hospital, Orange, CA, United States
| | - Nelly Mauras
- Division of Endocrinology, Nemours Children’s Health, Jacksonville, FL, United States
| | - Mitchell Geffner
- The Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States
- Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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4
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Liu XQ, Luo M, Liu Q, Yang GC. A Novel Mutation in the Myosin Binding Protein C Gene in a Prader-Willi Syndrome Pedigree. Reprod Sci 2021; 28:2718-2722. [PMID: 34076875 DOI: 10.1007/s43032-021-00620-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 05/13/2021] [Indexed: 11/29/2022]
Abstract
Prader-Willi syndrome (PWS) is a neurogenetic disorder caused by deficiency expression of paternally imprinted genes of the chromosomal region 15. In this study, we report a novel mutation in the myosin binding protein C (MYBPC3) gene in a Prader-Willi syndrome pedigree. Next-generation sequencing (NGS) and Sanger sequencing were performed to define and confirm the MYBPC3 gene mutation. Bioinformatics analysis was also performed for the mutated MYBPC3 protein using available software tools. The proband was diagnosed as PWS with about 4.727Mb copy number missed in the long arm of chromosome 15 and treated with growth hormone on 0.3 IU/day. Sanger sequencing identified a novel heterozygous mutation in the MYBPC3 gene, c.2002C>G (p.R668G). Bioinformatics analysis suggested the variant disease-causing; the Pro residue at 668 in the MYBPC3 protein was highly conserved. Moreover, interactions among MYBPC3 and other proteins suggested the potential effects on the development of cardiomyopathies. This is the first report of PWS with MYBPC3 gene mutation. Besides general examinations, it is vital for physicians to amply molecular genetics to get an accurate diagnosis in the clinic especially for rare diseases.
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Affiliation(s)
- Xiao-Qun Liu
- Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Zhong Xing North street 568, Yuecheng District, Shaoxing, Zhejiang Province, People's Republic of China, 312000.,Shaoxing University School of Medicine, Shaoxing, PR China, 312000
| | - Man Luo
- Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Zhong Xing North street 568, Yuecheng District, Shaoxing, Zhejiang Province, People's Republic of China, 312000.,Shaoxing University School of Medicine, Shaoxing, PR China, 312000
| | - Qi Liu
- Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Zhong Xing North street 568, Yuecheng District, Shaoxing, Zhejiang Province, People's Republic of China, 312000. .,Shaoxing University School of Medicine, Shaoxing, PR China, 312000.
| | - Guo-Can Yang
- Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Zhong Xing North street 568, Yuecheng District, Shaoxing, Zhejiang Province, People's Republic of China, 312000. .,Shaoxing University School of Medicine, Shaoxing, PR China, 312000.
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Strom SP, Hossain WA, Grigorian M, Li M, Fierro J, Scaringe W, Yen HY, Teguh M, Liu J, Gao H, Butler MG. A Streamlined Approach to Prader-Willi and Angelman Syndrome Molecular Diagnostics. Front Genet 2021; 12:608889. [PMID: 34046054 PMCID: PMC8148043 DOI: 10.3389/fgene.2021.608889] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/23/2021] [Indexed: 11/13/2022] Open
Abstract
Establishing or ruling out a molecular diagnosis of Prader–Willi or Angelman syndrome (PWS/AS) presents unique challenges due to the variety of different genetic alterations that can lead to these conditions. Point mutations, copy number changes, uniparental isodisomy (i-UPD) 15 of two subclasses (segmental or total isodisomy), uniparental heterodisomy (h-UPD), and defects in the chromosome 15 imprinting center can all cause PWS/AS. Here, we outline a combined approach using whole-exome sequencing (WES) and DNA methylation data with methylation-sensitive multiplex ligation-dependent probe amplification (MLPA) to establish both the disease diagnosis and the mechanism of disease with high sensitivity using current standard of care technology and improved efficiency compared to serial methods. The authors encourage the use of this approach in the clinical setting to confirm and establish the diagnosis and genetic defect which may account for the secondary genetic conditions that may be seen in those with isodisomy 15, impacting surveillance and counseling with more accurate recurrence risks. Other similarly affected individuals due to other gene disorders or cytogenetic anomalies such as Rett syndrome or microdeletions would also be identified with this streamlined approach.
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Affiliation(s)
| | - Waheeda A Hossain
- Department of Psychiatry and Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States
| | | | - Mickey Li
- Fulgent Genetics, Temple City, CA, United States
| | | | | | - Hai-Yun Yen
- Fulgent Genetics, Temple City, CA, United States
| | | | - Joanna Liu
- Fulgent Genetics, Temple City, CA, United States
| | - Harry Gao
- Fulgent Genetics, Temple City, CA, United States
| | - Merlin G Butler
- Department of Psychiatry and Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States
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Cataldi M, Arnaldi D, Tucci V, De Carli F, Patti G, Napoli F, Pace M, Maghnie M, Nobili L. Sleep disorders in Prader-Willi syndrome, evidence from animal models and humans. Sleep Med Rev 2021; 57:101432. [PMID: 33567377 DOI: 10.1016/j.smrv.2021.101432] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 02/06/2023]
Abstract
Prader-Willi Syndrome (PWS) is a complex genetic disorder with multiple cognitive, behavioral and endocrine dysfunctions. Sleep alterations and sleep disorders such as Sleep-disordered breathing and Central disorders of hypersomnolence are frequently recognized (either isolated or in comorbidity). The aim of the review is to highlight the pathophysiology and the clinical features of sleep disorders in PWS, providing the basis for early diagnosis and management. We reviewed the genetic features of the syndrome and the possible relationship with sleep alterations in animal models, and we described sleep phenotypes, diagnostic tools and therapeutic approaches in humans. Moreover, we performed a meta-analysis of cerebrospinal fluid orexin levels in patients with PWS; significantly lower levels of orexin were detected in PWS with respect to control subjects (although significantly higher than the ones of narcoleptic patients). Sleep disorders in humans with PWS are multifaceted and are often the result of different mechanisms. Since hypothalamic dysfunction seems to partially influence metabolic, respiratory and sleep/wake characteristics of this syndrome, additional studies are required in this framework.
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Affiliation(s)
- Matteo Cataldi
- Unit of Child Neuropsychiatry, Department of Medical and Surgical Neuroscience and Rehabilitation, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Dario Arnaldi
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Valter Tucci
- Genetics and Epigenetics of Behaviour Laboratory, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Fabrizio De Carli
- Institute of Bioimaging and Molecular Physiology, National Research Council, Genoa, Italy
| | - Giuseppa Patti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; Department of Pediatrics, Istituto Giannina Gaslini, University of Genoa, Genoa, Italy
| | - Flavia Napoli
- Department of Pediatrics, Istituto Giannina Gaslini, University of Genoa, Genoa, Italy
| | - Marta Pace
- Genetics and Epigenetics of Behaviour Laboratory, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Mohamad Maghnie
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; Department of Pediatrics, Istituto Giannina Gaslini, University of Genoa, Genoa, Italy
| | - Lino Nobili
- Unit of Child Neuropsychiatry, Department of Medical and Surgical Neuroscience and Rehabilitation, IRCCS Istituto Giannina Gaslini, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy.
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Ragusa L, Crinò A, Grugni G, Reale L, Fiorencis A, Licenziati MR, Faienza MF, Wasniewska M, Delvecchio M, Franzese A, Rutigliano I, Fusilli P, Corica D, Campana G, Greco D, Chiarito M, Sacco M, Toscano S, Marini MG. Caring and living with Prader-Willi syndrome in Italy: integrating children, adults and parents' experiences through a multicentre narrative medicine research. BMJ Open 2020; 10:e036502. [PMID: 32764084 PMCID: PMC7412587 DOI: 10.1136/bmjopen-2019-036502] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES Prader-Willi syndrome (PWS) significantly impacts health-related quality of life; however, its relational and existential aspects remain unknown in Italian clinical and social debate. The project aimed to investigate the impact of PWS on illness experience through narrative medicine (NM) to understand the daily life, needs and resources of patients with PWS and their caregivers, and to furnish insights for clinical practice. DESIGN AND SETTING The project involved 10 medical centres of the Italian Network for Rare Diseases and PWS family associations and targeted underage and adult patients with PWS and their caregivers. Written interviews, composed by a sociodemographic survey and a narrative, were collected through the project's website. Three dedicated illness plots employed evocative and open words to facilitate individual expression and to encourage reflection. Narratives were analysed through NVivo software. Researchers discussed the results with the project's steering committee. PARTICIPANTS Twenty-one children and adolescents and 34 adults with PWS joined the project, as well as 138 caregivers. A PWS diagnosis or the caregiving of a patient with PWS older than 5 years represented the eligibility criteria, as well as the willingness to share their illness experience by writing and the ability to communicate in Italian. RESULTS The analysis of narratives led to understanding the PWS social and relational issues concerning diagnosis and current management, PWS daily experiences and social contexts, PWS implications in the working sphere and participants' future perspectives. Narratives demonstrated that PWS management affects relationships and work-life balance and that social stigma remains present. CONCLUSION The project represented the first effort to investigate the impact of PWS on illness experience in Italy through NM while considering the perspectives of patients with PWS and their caregivers. The findings indicated that a multiprofessional approach is fundamental to ensure adequate treatment and provided elements for its improvement.
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Affiliation(s)
- Letizia Ragusa
- Unit of Paediatrics and Medical Genetics, OASI Maria SS Research Institute, Troina, Enna, Italy
| | - Antonio Crinò
- Autoimmune Endocrine Diseases Unit, Bambino Gesù Paediatric Hospital-Palidoro Research Institute, Rome, Italy
| | - Graziano Grugni
- Department of Auxology, Istituto Auxologico Italiano, Verbania, Italy
| | - Luigi Reale
- Healthcare Area, Fondazione ISTUD, Baveno, Verbano-Cusio-Ossola, Italy
| | | | - Maria Rosaria Licenziati
- Obesity and Endocrine Disease Unit, Department of Neuroscience, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Maria Felicia Faienza
- Pediatrics Unit, Department of Biomedical Sciences and Human Oncology, Universita degli Studi di Bari Aldo Moro, Bari, Italy
| | - Malgorzata Wasniewska
- Department of Human Pathology of Adulthood and Childhood 'G Barresi', University of Messina, Messina, Italy
| | - Maurizio Delvecchio
- Metabolic Diseases, Clinical Genetics and Diabetology Unit, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Adriana Franzese
- Department of Translational Medical Sciences, University of Naples Federico II, Napoli, Campania, Italy
| | - Irene Rutigliano
- Department of Pediatrics, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Paola Fusilli
- UOC Neonatologia, Ospedale 'Spirito Santo', Pescara, Italy
| | - Domenico Corica
- Department of Human Pathology of Adulthood and Childhood 'G Barresi', University of Messina, Messina, Italy
| | - Giuseppina Campana
- Obesity and Endocrine Disease Unit, Department of Neuroscience, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Donatella Greco
- Unit of Paediatrics and Medical Genetics, OASI Maria SS Research Institute, Troina, Enna, Italy
| | - Mariangela Chiarito
- Department of Biomedical Sciences and Human Oncology, University of Bari 'A Moro', Bari, Italy
| | - Michele Sacco
- Department of Pediatrics, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Silvia Toscano
- Department of Translational Sciences, University Federico II, Naples, Italy
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Genovese A, Butler MG. Clinical Assessment, Genetics, and Treatment Approaches in Autism Spectrum Disorder (ASD). Int J Mol Sci 2020; 21:E4726. [PMID: 32630718 PMCID: PMC7369758 DOI: 10.3390/ijms21134726] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 12/16/2022] Open
Abstract
Autism spectrum disorder (ASD) consists of a genetically heterogenous group of neurobehavioral disorders characterized by impairment in three behavioral domains including communication, social interaction, and stereotypic repetitive behaviors. ASD affects more than 1% of children in Western societies, with diagnoses on the rise due to improved recognition, screening, clinical assessment, and diagnostic testing. We reviewed the role of genetic and metabolic factors which contribute to the causation of ASD with the use of new genetic technology. Up to 40 percent of individuals with ASD are now diagnosed with genetic syndromes or have chromosomal abnormalities including small DNA deletions or duplications, single gene conditions, or gene variants and metabolic disturbances with mitochondrial dysfunction. Although the heritability estimate for ASD is between 70 and 90%, there is a lower molecular diagnostic yield than anticipated. A likely explanation may relate to multifactorial causation with etiological heterogeneity and hundreds of genes involved with a complex interplay between inheritance and environmental factors influenced by epigenetics and capabilities to identify causative genes and their variants for ASD. Behavioral and psychiatric correlates, diagnosis and genetic evaluation with testing are discussed along with psychiatric treatment approaches and pharmacogenetics for selection of medication to treat challenging behaviors or comorbidities commonly seen in ASD. We emphasize prioritizing treatment based on targeted symptoms for individuals with ASD, as treatment will vary from patient to patient based on diagnosis, comorbidities, causation, and symptom severity.
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Affiliation(s)
| | - Merlin G. Butler
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS 66160, USA;
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Butler MG, Duis J. Chromosome 15 Imprinting Disorders: Genetic Laboratory Methodology and Approaches. Front Pediatr 2020; 8:154. [PMID: 32478012 PMCID: PMC7235373 DOI: 10.3389/fped.2020.00154] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/20/2020] [Indexed: 01/23/2023] Open
Abstract
Chromosome 15 imprinting disorders include Prader-Willi (PWS) and Angelman (AS) syndromes, which are caused by absent expression from the paternal and maternal alleles in the chromosome 15q11. 2-q13 region, respectively. In addition, chromosome 15q duplication caused by the presence of at least one additional maternally derived copy of the 15q11.2-q13 region can lead to seizures, cognitive and behavioral problems. We focus on PWS and AS in the report, and expand the discussion of clinical care and description with genetic testing to include high-resolution studies to more specifically characterize the molecular mechanisms of disease. The importance of early diagnosis with the necessity for accurate molecular characterization through a step-wise algorithm is emphasized in an era of targeted therapeutic interventions. We present a flowchart to aid in ordering specialized genetic testing as several methods are available for patients presenting with features of PWS and/or AS.
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Affiliation(s)
- Merlin G Butler
- Division of Research and Genetics, Departments of Psychiatry and Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States
| | - Jessica Duis
- Section of Genetics and Inherited Metabolic Diseases, Department of Pediatrics, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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Early Diagnosis in Prader-Willi Syndrome Reduces Obesity and Associated Co-Morbidities. Genes (Basel) 2019; 10:genes10110898. [PMID: 31698873 PMCID: PMC6896038 DOI: 10.3390/genes10110898] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 11/01/2019] [Accepted: 11/04/2019] [Indexed: 02/07/2023] Open
Abstract
Prader–Willi syndrome (PWS) is an imprinting genetic disorder characterized by lack of expression of genes on the paternal chromosome 15q11–q13 region. Growth hormone (GH) replacement positively influences stature and body composition in PWS. Our hypothesis was that early diagnosis delays onset of obesity in PWS. We studied 352 subjects with PWS, recruited from the NIH Rare Disease Clinical Research Network, to determine if age at diagnosis, ethnicity, gender, and PWS molecular class influenced the age they first become heavy, as determined by their primary care providers, and the age they first developed an increased appetite and began seeking food. The median ages that children with PWS became heavy were 10 years, 6 years and 4 years for age at diagnosis < 1 year, between 1 and 3 years, and greater than 3 years of age, respectively. The age of diagnosis and ethnicity were significant factors influencing when PWS children first became heavy (p < 0.01), however gender and the PWS molecular class had no influence. Early diagnosis delayed the onset of becoming heavy in individuals with PWS, permitting early GH and other treatment, thus reducing the risk of obesity-associated co-morbidities. Non-white individuals had an earlier onset of becoming heavy.
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Hartin SN, Hossain WA, Francis D, Godler DE, Barkataki S, Butler MG. Analysis of the Prader-Willi syndrome imprinting center using droplet digital PCR and next-generation whole-exome sequencing. Mol Genet Genomic Med 2019; 7:e00575. [PMID: 30793526 PMCID: PMC6465664 DOI: 10.1002/mgg3.575] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/13/2018] [Accepted: 01/02/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Detailed analysis of imprinting center (IC) defects in individuals with Prader-Willi syndrome (PWS) is not readily available beyond chromosomal microarray (MA) analysis, and such testing is important for a more accurate diagnosis and recurrence risks. This is the first feasibility study of newly developed droplet digital polymerase chain reaction (ddPCR) examining DNA copy number differences in the PWS IC region of those with IC defects. METHODS The study cohort included 17 individuals without 15q11-q13 deletions or maternal disomy but with IC defects as determined by genotype analysis showing biparental inheritance. Seven sets of parents and two healthy, unrelated controls were also analyzed. RESULTS Copy number differences were distinguished by comparing the number of positive droplets detected by IC probes to those from a chromosome 15 reference probe, GABRβ3. The ddPCR findings were compared to results from other methods including MA, and whole-exome sequencing (WES) with 100% concordance. The study also estimated the frequency of IC microdeletions and identified gene variants by WES that may impact phenotypes including CPT2 and NTRK1 genes. CONCLUSION Droplet digital polymerase chain reaction is a cost-effective method that can be used to confirm the presence of microdeletions in PWS with impact on genetic counseling and recurrence risks for families.
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Affiliation(s)
- Samantha N. Hartin
- Departments of Psychiatry & Behavioral Sciences and PediatricsUniversity of Kansas Medical CenterKansas CityKansas
| | - Waheeda A. Hossain
- Departments of Psychiatry & Behavioral Sciences and PediatricsUniversity of Kansas Medical CenterKansas CityKansas
| | - David Francis
- Cyto‐molecular Diagnostic Research LaboratoryRoyal Children's Hospital, Victorian Clinical Genetics Services and Murdoch Children's Research InstituteMelbourneVictoriaAustralia
| | - David E. Godler
- Cyto‐molecular Diagnostic Research LaboratoryRoyal Children's Hospital, Victorian Clinical Genetics Services and Murdoch Children's Research InstituteMelbourneVictoriaAustralia
| | | | - Merlin G. Butler
- Departments of Psychiatry & Behavioral Sciences and PediatricsUniversity of Kansas Medical CenterKansas CityKansas
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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: 167] [Impact Index Per Article: 33.4] [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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Costa RA, Ferreira IR, Cintra HA, Gomes LHF, Guida LDC. Genotype-Phenotype Relationships and Endocrine Findings in Prader-Willi Syndrome. Front Endocrinol (Lausanne) 2019; 10:864. [PMID: 31920975 PMCID: PMC6923197 DOI: 10.3389/fendo.2019.00864] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/26/2019] [Indexed: 12/13/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a complex imprinting disorder related to genomic errors that inactivate paternally-inherited genes on chromosome 15q11-q13 with severe implications on endocrine, cognitive and neurologic systems, metabolism, and behavior. The absence of expression of one or more genes at the PWS critical region contributes to different phenotypes. There are three molecular mechanisms of occurrence: paternal deletion of the 15q11-q13 region; maternal uniparental disomy 15; or imprinting defects. Although there is a clinical diagnostic consensus criteria, DNA methylation status must be confirmed through genetic testing. The endocrine system can be the most affected in PWS, and growth hormone replacement therapy provides improvement in growth, body composition, and behavioral and physical attributes. A key feature of the syndrome is the hypothalamic dysfunction that may be the basis of several endocrine symptoms. Clinical and molecular complexity in PWS enhances the importance of genetic diagnosis in therapeutic definition and genetic counseling. So far, no single gene mutation has been described to contribute to this genetic disorder or related to any exclusive symptoms. Here we proposed to review individually disrupted genes within the PWS critical region and their reported clinical phenotypes related to the syndrome. While genes such as MKRN3, MAGEL2, NDN, or SNORD115 do not address the full spectrum of PWS symptoms and are less likely to have causal implications in PWS major clinical signs, SNORD116 has emerged as a critical, and possibly, a determinant candidate in PWS, in the recent years. Besides that, the understanding of the biology of the PWS SNORD genes is fairly low at the present. These non-coding RNAs exhibit all the hallmarks of RNA methylation guides and can be incorporated into ribonucleoprotein complexes with possible hypothalamic and endocrine functions. Also, DNA conservation between SNORD sequences across placental mammals strongly suggests that they have a functional role as RNA entities on an evolutionary basis. The broad clinical spectrum observed in PWS and the absence of a clear genotype-phenotype specific correlation imply that the numerous genes involved in the syndrome have an additive deleterious effect on different phenotypes when deficiently expressed.
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