Hanae Daha Belghiti, Meriame Abbassi, Hanane Sayel, Mohamed Ahakoud, Badr Eddine El Makhzen, Norman Lee, Silvia Russo, Sana Chaouki, Laila Bouguenouch
{"title":"Impact of Deletion on Angelman Syndrome Phenotype Variability: Phenotype-Genotype Correlation in 97 Patients with Motor Developmental Delay.","authors":"Hanae Daha Belghiti, Meriame Abbassi, Hanane Sayel, Mohamed Ahakoud, Badr Eddine El Makhzen, Norman Lee, Silvia Russo, Sana Chaouki, Laila Bouguenouch","doi":"10.1055/s-0042-1751268","DOIUrl":null,"url":null,"abstract":"<p><p>Angelman syndrome (AS) is a rare neurodevelopmental disorder due to genetic defects involving chromosome 15, known by intellectual disability, cognitive and behavioral disorders, ataxia, delayed motor development, and seizures. This study highlights the clinical spectrum and molecular research to establish the genotype-phenotype correlation in the pediatric Moroccan population. Methylation-specific-polymerase chain reaction (MS-PCR) is a primordial technique not only to identify the genetic mechanism of AS but also to characterize the different molecular classes induced in the appearance of the clinical symptoms. Patients with positive methylation profile were additionally studied by fluorescent in situ hybridization. Sequencing analysis of the UBE3A gene was performed for patients with negative MS-PCR. We used Fisher's test to assess differences in the distribution of features frequencies among the deletional and the nondeletional group. Statistical analysis was performed using R project. We identified from 97 patients diagnosed with AS, 14 (2.06%) had a classical AS phenotype, while 70 (84.5%) patients displayed a subset of consistent and frequent criteria. Development delay was shown severe in 63% and moderate in 37%. Nineteen out of 97 of them had MS-PCR positive in which 17 (89.47%) had 15q11-q13 deletion. Deletion patients presented a higher incidence of epileptic seizures ( <i>p</i> = 0.04), ataxia ( <i>p</i> = 0.0008), and abnormal electroencephalogram (EEG) profile ( <i>p</i> = 0.003). We further found out a frameshift deletion located at exon 9 of the UBE3A gene discovered in a 5 years old patient. We report in this study the genotype-phenotype correlation using different molecular testing. Correlation analysis did not reveal any statistical differences in phenotypic dissimilarity between deletion and nondeletion groups for most clinical features, except the correlation was highly significant in the abnormal EEG. According to our findings, we recommend offering MS-PCR analysis to all patients with severe intellectual disability, developmental delay, speech impairment, happy demeanor, and hypopigmentation.</p>","PeriodicalId":16695,"journal":{"name":"Journal of pediatric genetics","volume":null,"pages":null},"PeriodicalIF":0.4000,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10984711/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of pediatric genetics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1055/s-0042-1751268","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/3/1 0:00:00","PubModel":"eCollection","JCR":"Q4","JCRName":"PEDIATRICS","Score":null,"Total":0}
引用次数: 0
Abstract
Angelman syndrome (AS) is a rare neurodevelopmental disorder due to genetic defects involving chromosome 15, known by intellectual disability, cognitive and behavioral disorders, ataxia, delayed motor development, and seizures. This study highlights the clinical spectrum and molecular research to establish the genotype-phenotype correlation in the pediatric Moroccan population. Methylation-specific-polymerase chain reaction (MS-PCR) is a primordial technique not only to identify the genetic mechanism of AS but also to characterize the different molecular classes induced in the appearance of the clinical symptoms. Patients with positive methylation profile were additionally studied by fluorescent in situ hybridization. Sequencing analysis of the UBE3A gene was performed for patients with negative MS-PCR. We used Fisher's test to assess differences in the distribution of features frequencies among the deletional and the nondeletional group. Statistical analysis was performed using R project. We identified from 97 patients diagnosed with AS, 14 (2.06%) had a classical AS phenotype, while 70 (84.5%) patients displayed a subset of consistent and frequent criteria. Development delay was shown severe in 63% and moderate in 37%. Nineteen out of 97 of them had MS-PCR positive in which 17 (89.47%) had 15q11-q13 deletion. Deletion patients presented a higher incidence of epileptic seizures ( p = 0.04), ataxia ( p = 0.0008), and abnormal electroencephalogram (EEG) profile ( p = 0.003). We further found out a frameshift deletion located at exon 9 of the UBE3A gene discovered in a 5 years old patient. We report in this study the genotype-phenotype correlation using different molecular testing. Correlation analysis did not reveal any statistical differences in phenotypic dissimilarity between deletion and nondeletion groups for most clinical features, except the correlation was highly significant in the abnormal EEG. According to our findings, we recommend offering MS-PCR analysis to all patients with severe intellectual disability, developmental delay, speech impairment, happy demeanor, and hypopigmentation.
期刊介绍:
The Journal of Pediatric Genetics is an English multidisciplinary peer-reviewed international journal publishing articles on all aspects of genetics in childhood and of the genetics of experimental models. These topics include clinical genetics, molecular genetics, biochemical genetics, medical genetics, dysmorphology, teratology, genetic counselling, genetic engineering, formal genetics, neuropsychiatric genetics, behavioral genetics, community genetics, cytogenetics, hereditary or syndromic cancer genetics, genetic mapping, reproductive genetics, fetal pathology and prenatal diagnosis, multiple congenital anomaly syndromes, and molecular embryology of birth defects. Journal of Pediatric Genetics provides an in-depth update on new subjects and current comprehensive coverage of the latest techniques used in the diagnosis of childhood genetics. Journal of Pediatric Genetics encourages submissions from all authors throughout the world. The following articles will be considered for publication: editorials, original and review articles, short report, rapid communications, case reports, letters to the editor, and book reviews. The aim of the journal is to share and disseminate knowledge between all disciplines in the field of pediatric genetics. This journal is a publication of the World Pediatric Society: http://www.worldpediatricsociety.org/ The Journal of Pediatric Genetics is available in print and online. Articles published ahead of print are available via the eFirst service on the Thieme E-Journals platform.