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A unique Smith-Magenis patient with a de novo intragenic deletion on the maternally inherited overexpressed RAI1 allele. Eur J Hum Genet 2022; 30:1233-1238. [PMID: 35821519 PMCID: PMC9626456 DOI: 10.1038/s41431-022-01143-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 05/01/2022] [Accepted: 06/21/2022] [Indexed: 02/04/2023] Open
Abstract
RAI1 is a dosage-sensitive gene whose decreased or increased expression by recurrent and non-recurrent 17p11.2 deletions or duplications causes Smith-Magenis (SMS) or Potocki-Lupski syndromes (PTLS), respectively. Here we report on a 21-year-old female patient showing SMS phenotype who was found to carry a 3.4 kb de novo intragenic RAI1 deletion. Interestingly, a significant increase in RAI1 transcript levels was identified in the patient's, brother's and mother's peripheral blood cells. Allele-specific dosage analysis revealed that the patient's maternally inherited overexpressed RAI1 allele harbors the intragenic deletion, confirming the SMS diagnosis due to the presence of a single wild-type RAI1 functional allele. The mother and brother do not present any PTLS neurologic/behavioral clinical features. Extensive sequencing of RAI1 promoter and predicted regulatory regions showed no potential causative variants accounting for gene overexpression. However, the mother and both children share a novel private missense variant in RAI1 exon 3, currently classified as a VUS (uncertain significance), though predicted by two bioinformatic tools to disrupt the binding site of one specific transcription factor. The reported familial case, the second showing RAI1 overexpression in the absence of RAI1 duplication, may help to understand the regulation of RAI1 dosage sensitivity although its phenotypic effect remains to be determined.
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Javed S, Selliah T, Lee YJ, Huang WH. Dosage-sensitive genes in autism spectrum disorders: From neurobiology to therapy. Neurosci Biobehav Rev 2020; 118:538-567. [PMID: 32858083 DOI: 10.1016/j.neubiorev.2020.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/26/2020] [Accepted: 08/17/2020] [Indexed: 12/24/2022]
Abstract
Autism spectrum disorders (ASDs) are a group of heterogenous neurodevelopmental disorders affecting 1 in 59 children. Syndromic ASDs are commonly associated with chromosomal rearrangements or dosage imbalance involving a single gene. Many of these genes are dosage-sensitive and regulate transcription, protein homeostasis, and synaptic function in the brain. Despite vastly different molecular perturbations, syndromic ASDs share core symptoms including social dysfunction and repetitive behavior. However, each ASD subtype has a unique pathogenic mechanism and combination of comorbidities that require individual attention. We have learned a great deal about how these dosage-sensitive genes control brain development and behaviors from genetically-engineered mice. Here we describe the clinical features of eight monogenic neurodevelopmental disorders caused by dosage imbalance of four genes, as well as recent advances in using genetic mouse models to understand their pathogenic mechanisms and develop intervention strategies. We propose that applying newly developed quantitative molecular and neuroscience technologies will advance our understanding of the unique neurobiology of each disorder and enable the development of personalized therapy.
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Affiliation(s)
- Sehrish Javed
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Tharushan Selliah
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Yu-Ju Lee
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Wei-Hsiang Huang
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.
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Ciaccio C, Pantaleoni C, Milani D, Alfei E, Sciacca FL, Canafoglia L, Erbetta A, D'Arrigo S. Neurological phenotype of Potocki-Lupski syndrome. Am J Med Genet A 2020; 182:2317-2324. [PMID: 33043631 DOI: 10.1002/ajmg.a.61789] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/19/2020] [Accepted: 06/25/2020] [Indexed: 12/20/2022]
Abstract
Potocki-Lupski syndrome is a condition mainly characterized by infantile hypotonia, developmental delay/intellectual disability (DD/ID), and congenital anomalies, caused by duplications of the 17p11.2 region, encompassing RAI1 gene. Its clinical presentation is extremely variable, especially for what concerns the cognitive level and the behavioral phenotype. Such aspects, as well as the dysmorphic/malformative ones, have been covered by previous studies; otherwise neurological features have never been systematically described. In order to delineate the neurological phenotype of Potocki-Lupski Syndrome, we collect an 8-patients cohort. Developmental milestones are delayed and a mild to moderate cognitive impairment is present in all patients, variably associated with features of autism spectrum disorder, behavioral disturb, and sleep disturb. Hypotonia appears a less frequent finding than what previously reported, while motor clumsiness/coordination impairment is frequent. EGG registration demonstrated a common pattern with excess of diffuse rhythmic activity in sleep phases or while the patient is falling asleep. Brain MRI did not reveal common anomalies, although unspecific white matter changes may be present. We discuss such findings and compare them to literature data, offering an overview on the neurological and cognitive-behavioral presentation of the syndrome.
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Affiliation(s)
- Claudia Ciaccio
- Developmental Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Chiara Pantaleoni
- Developmental Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Donatella Milani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Pediatria Alta Intensità di Cura, Milan, Italy
| | - Enrico Alfei
- Developmental Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Pediatric Neurology Unit-Vittore Buzzi Children's Hospital-ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Francesca L Sciacca
- Laboratory of Cytogenetic, Neurological Biochemistry and Neuropharmacology Unit, Department of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Canafoglia
- Neurophysiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessandra Erbetta
- Department of Neuroradiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Stefano D'Arrigo
- Developmental Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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Abstract
Smith-Magenis syndrome is a genetic disorder caused by a microdeletion involving the retinoic acid-induced 1 (RAI1) gene that maps on the short arm of chromosome 17p11.2 or a pathogenic mutation of RAI1. Smith-Magenis syndrome affects patients through numerous congenital anomalies, intellectual disabilities, behavioral challenges, and sleep disturbances. The sleep abnormalities associated with Smith-Magenis syndrome can include frequent nocturnal arousals, early morning awakenings, and sleep attacks during the day. The sleep problems associated with Smith-Magenis syndrome are attributed to haploinsufficiency of the RAI1 gene. One consequence of reduced function of RAI1, and characteristic of Smith-Magenis syndrome, is an inversion of melatonin secretion resulting in a diurnal rather than nocturnal pattern. Treatment of sleep problems in people with Smith-Magenis syndrome generally involves a combination of sleep hygiene techniques, supplemental melatonin, and/or other medications, such as melatonin receptor agonists, β1-adrenergic antagonists, and stimulant medications, to improve sleep outcomes. Improvement in sleep has been shown to improve behavioral outcomes, which in turn improves the quality of life for both patients and their caregivers.
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Affiliation(s)
- Kevin A Kaplan
- Department of Pediatrics at Baylor College of Medicine, Houston, TX, USA.
- Section of Pediatric Pulmonary at Texas Children's Hospital, Houston, TX, USA.
- Section of Sleep Medicine at Texas Children's Hospital, Houston, TX, USA.
| | - Sarah H Elsea
- Department of Molecular and Human Genetics at Baylor College of Medicine, Houston, TX, USA
| | - Lorraine Potocki
- Department of Molecular and Human Genetics at Baylor College of Medicine, Houston, TX, USA
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Stimulant and Antipsychotic Use for Symptom Management of a Patient With Potocki Lupski Syndrome: Case Report. J Clin Psychopharmacol 2020; 39:403-404. [PMID: 31188237 DOI: 10.1097/jcp.0000000000001069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kaplan K, McCool C, Lupski JR, Glaze D, Potocki L. Objective measures of sleep disturbances in children with Potocki-Lupski syndrome. Am J Med Genet A 2019; 179:1982-1986. [PMID: 31342617 DOI: 10.1002/ajmg.a.61307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/05/2019] [Accepted: 07/10/2019] [Indexed: 11/06/2022]
Abstract
Potocki-Lupski syndrome (PTLS; MIM 610883) is a neurodevelopmental disorder caused by a microduplication, a 3.7 Mb copy number variant, mapping within chromosome 17p11.2, encompassing the dosage-sensitive RAI1 gene. Whereas RAI1 triplosensitivity causes PTLS, haploinsufficiency of RAI1 due to 17p11.2 microdeletion causes the clinically distinct Smith-Magenis syndrome (SMS; MIM 182290). Most individuals with SMS have an inversion of the melatonin cycle. Subjects with PTLS have mild sleep disturbances such as sleep apnea with no melatonin abnormalities described. Sleep patterns and potential disturbances in subjects with PTLS have not been objectively characterized. We delineated sleep characteristics in 23 subjects with PTLS who underwent a polysomnogram at Texas Children's Hospital. Eleven of these subjects (58%) completed the Child's Sleep Habits Questionnaire (CSHQ). Urinary melatonin was measured in one patient and published previously. While the circadian rhythm of melatonin in PTLS appears not to be disrupted, we identified significant differences in sleep efficiency, percentage of rapid eye movement sleep, oxygen nadir, obstructive apnea hypopnea index, and periodic limb movements between prepubertal subjects with PTLS and previously published normative data. Data from the CSHQ indicate that 64% (7/11) of parents do not identify a sleep disturbance in their children. Our data indicate that younger individuals, <10 years, with PTLS have statistically significant abnormalities in five components of sleep despite lack of recognition of substantial sleep disturbances by parents. Our data support the contention that patients with PTLS should undergo clinical evaluations for sleep disordered breathing and periodic limb movement disorder, both of which are treatable conditions.
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Affiliation(s)
- Kevin Kaplan
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Children's Sleep Center, Baylor College of Medicine, Houston, Texas.,Department of Pulmonary, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | - Caroline McCool
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - James R Lupski
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Daniel Glaze
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Children's Sleep Center, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas.,Department of Neurology, Baylor College of Medicine, Houston, Texas
| | - Lorraine Potocki
- Texas Children's Hospital, Baylor College of Medicine, Houston, Texas.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
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Poisson A, Nicolas A, Bousquet I, Raverot V, Gronfier C, Demily C. Smith-Magenis Syndrome: Molecular Basis of a Genetic-Driven Melatonin Circadian Secretion Disorder. Int J Mol Sci 2019; 20:E3533. [PMID: 31330985 PMCID: PMC6679101 DOI: 10.3390/ijms20143533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/08/2019] [Accepted: 07/17/2019] [Indexed: 01/09/2023] Open
Abstract
Smith-Magenis syndrome (SMS), linked to Retinoic Acid Induced (RAI1) haploinsufficiency, is a unique model of the inversion of circadian melatonin secretion. In this regard, this model is a formidable approach to better understand circadian melatonin secretion cycle disorders and the role of the RAI1 gene in this cycle. Sleep-wake cycle disorders in SMS include sleep maintenance disorders with a phase advance and intense sleepiness around noon. These disorders have been linked to a general disturbance of sleep-wake rhythm and coexist with inverted secretion of melatonin. The exact mechanism underlying the inversion of circadian melatonin secretion in SMS has rarely been discussed. We suggest three hypotheses that could account for the inversion of circadian melatonin secretion and discuss them. First, inversion of the circadian melatonin secretion rhythm could be linked to alterations in light signal transduction. Second, this inversion could imply global misalignment of the circadian system. Third, the inversion is not linked to a global circadian clock shift but rather to a specific impairment in the melatonin secretion pathway between the suprachiasmatic nuclei (SCN) and pinealocytes. The development of diurnal SMS animal models that produce melatonin appears to be an indispensable step to further understand the molecular basis of the circadian melatonin secretion rhythm.
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Affiliation(s)
- Alice Poisson
- GénoPsy, Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Centre Hospitalier le Vinatier and EDR-Psy Q19 Team (Centre National de la Recherche Scientifique & Lyon 1 Claude Bernard University), 69678 Bron, France.
| | - Alain Nicolas
- GénoPsy, Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Centre Hospitalier le Vinatier and EDR-Psy Q19 Team (Centre National de la Recherche Scientifique & Lyon 1 Claude Bernard University), 69678 Bron, France
| | - Idriss Bousquet
- GénoPsy, Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Centre Hospitalier le Vinatier and EDR-Psy Q19 Team (Centre National de la Recherche Scientifique & Lyon 1 Claude Bernard University), 69678 Bron, France
| | - Véronique Raverot
- Laboratoire d'hormonologie-CBPE, CHU de Lyon, 59, boulevard Pinel, 69677 Bron, France
| | - Claude Gronfier
- Lyon Neuroscience Research Center, Integrative Physiology of the Brain Arousal Systems, Waking Team, Inserm UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, 69675 Lyon, France
| | - Caroline Demily
- GénoPsy, Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Centre Hospitalier le Vinatier and EDR-Psy Q19 Team (Centre National de la Recherche Scientifique & Lyon 1 Claude Bernard University), 69678 Bron, France
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Abstract
PURPOSE OF REVIEW To provide an update of the most recent studies on Smith-Magenis syndrome (SMS) with a focus on the unique pattern of behavioral and sleep disturbances associated with the condition. RECENT FINDINGS The recent literature on SMS has focused on the characteristic severe behavioral and sleep disturbances. A better understanding of the underlying pathophysiological mechanisms and common clinical course has helped further characterize SMS, while much is left to be discovered in regard to effective treatment/management. SUMMARY SMS is a difficult to manage genetic condition defined by pervasive and progressive behavioral and sleep disturbances with a unique pattern that can often be easily discerned from other neurodevelopmental disorders. Common behavioral features include maladaptive/self-injurious, aggressive, stereotypic, and the newly appreciated food seeking behaviors associated with SMS. In addition, there is a sleep disturbance defined by an altered circadian rhythm with frequent nighttime waking and daytime sleepiness, causing patients and families significant distress. Small studies have suggested some treatment/management approaches to the behavioral and sleep disturbances, however, much remains to be discovered.
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Bissell S, Wilde L, Richards C, Moss J, Oliver C. The behavioural phenotype of Potocki-Lupski syndrome: a cross-syndrome comparison. J Neurodev Disord 2018; 10:2. [PMID: 29329513 PMCID: PMC5795277 DOI: 10.1186/s11689-017-9221-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 12/19/2017] [Indexed: 01/06/2023] Open
Abstract
Background Potocki-Lupski syndrome (PTLS) and Smith-Magenis syndrome (SMS) are related genomic disorders, as duplication 17p11.2 (associated with PTLS) is the reciprocal recombination product of the SMS microdeletion. While SMS has a relatively well-delineated behavioural phenotype, the behavioural profile in PTLS is less well defined, despite purported associations with autism spectrum disorder (ASD) and the suggestion that some behaviours may be diametric to those seen in SMS. Methods Caregivers of individuals with PTLS (N = 34; M age = 12.43, SD = 6.78) completed online behavioural questionnaires, including the Challenging Behaviour Questionnaire (CBQ), the Activity Questionnaire (TAQ), the Repetitive Behaviour Questionnaire (RBQ), the Mood, Interest and Pleasure Questionnaire-Short Form (MIPQ-S) and the Social Communication Questionnaire (SCQ), which assesses behaviours associated with ASD. Individuals with PTLS were matched on age and adaptive functioning to individuals with SMS (N = 31; M age = 13.61, SD = 6.85) and individuals with idiopathic ASD (N = 33; M age = 12.04, SD = 5.85) from an existing dataset. Results Individuals with PTLS and SMS were less impaired than those with idiopathic ASD on the communication and reciprocal social interaction subscales of the SCQ, but neither syndrome group differed from idiopathic ASD on the restricted, repetitive and stereotyped behaviours subscale. On the repetitive behaviour measure, individuals with PTLS and idiopathic ASD scored higher than individuals with SMS on the compulsive behaviour subscale. Rates of self-injury and property destruction were significantly lower in PTLS and idiopathic ASD than in SMS. No between-syndrome differences were found in relation to overactivity or mood; however, impulsivity was greater in SMS than in PTLS. Conclusions Findings suggest some overlap in the behavioural phenotype of PTLS and features of ASD symptomatology; however, the overall profile of behaviours in PTLS appears to be divergent from both idiopathic ASD and SMS. Relative to idiopathic ASD, PTLS is not characterised by communication or social interaction deficits. However, restricted and repetitive behaviours were evident in PTLS, and these may be characterised specifically by compulsive behaviours. While several behavioural differences were identified between PTLS and SMS, there was little evidence of diametric behavioural phenotypes, particularly in relation to social behaviour.
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Affiliation(s)
- Stacey Bissell
- Cerebra Centre for Neurodevelopmental Disorders, School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Lucy Wilde
- Cerebra Centre for Neurodevelopmental Disorders, School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK
| | - Caroline Richards
- Cerebra Centre for Neurodevelopmental Disorders, School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK
| | - Jo Moss
- Cerebra Centre for Neurodevelopmental Disorders, School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK.,Institute of Cognitive Neuroscience, University College London, Alexandra House, 17-19 Queen Square, London, WC1N 3AR, UK
| | - Chris Oliver
- Cerebra Centre for Neurodevelopmental Disorders, School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK
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