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Lourenço CM, Sallum JMF, Pereira AM, Girotto PN, Kok F, Vilela DRF, Barron E, Pessoa A, Oliveira BMD. A needle in a haystack? The impact of a targeted epilepsy gene panel in the identification of a treatable but rapidly progressive metabolic epilepsy: CLN2 disease. ARQUIVOS DE NEURO-PSIQUIATRIA 2024; 82:1-8. [PMID: 38763144 PMCID: PMC11102811 DOI: 10.1055/s-0044-1786854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/30/2024] [Indexed: 05/21/2024]
Abstract
BACKGROUND Neuronal ceroid lipofuscinoses (NCL) are a group of autosomal recessive, inherited, lysosomal, and neurodegenerative diseases that causes progressive dementia, seizures, movement disorders, language delay/regression, progressive visual failure, and early death. Neuronal ceroid lipofuscinosis type 2 (CLN2), caused by biallelic pathogenic variants of the TPP1 gene, is the only NCL with an approved targeted therapy. The laboratory diagnosis of CLN2 is established through highly specific tests, leading to diagnostic delays and eventually hampering the provision of specific treatment for patients with CLN2. Epilepsy is a common and clinically-identifiable feature among NCLs, and seizure onset is the main driver for families to seek medical care. OBJECTIVE To evaluate the results of the Latin America Epilepsy and Genetics Program, an epilepsy gene panel, as a comprehensive tool for the investigation of CLN2 among other genetic causes of epilepsy. METHODS A total of 1,284 patients with epilepsy without a specific cause who had at least 1 symptom associated with CLN2 were screened for variants in 160 genes associated with epilepsy or metabolic disorders presenting with epilepsy through an epilepsy gene panel. RESULTS Variants of the TPP1 gene were identified in 25 individuals (1.9%), 21 of them with 2 variants. The 2 most frequently reported variants were p.Arg208* and p.Asp276Val, and 2 novel variants were detected in the present study: p.Leu308Pro and c.89 + 3G > C Intron 2. CONCLUSION The results suggest that these genetic panels can be very useful tools to confirm or exclude CLN2 diagnosis and, if confirmed, provide disease-specific treatment for the patients.
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Affiliation(s)
| | - Juliana Maria Ferraz Sallum
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Oftalmologia e Ciências Visuais, São Paulo SP, Brazil.
| | | | | | - Fernando Kok
- Mendelics Análise Genômica, São Paulo SP, Brazil.
| | | | - Erika Barron
- BioMarin Brasil Farmacêutica Ltda., São Paulo SP, Brazil.
| | - André Pessoa
- Hospital Albert Sabin, Fortaleza CE, Brazil.
- Universidade Estadual do Ceará, Fortaleza CE, Brazil.
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Gao C, Liu N, Ma J, Zhao J, Zhao B, Song F, Dong R, Li Z, Lv Y, Liu Y, Gai Z. DCX variants in two unrelated Chinese families with subcortical band heterotopia: Two case reports and review of literature. Heliyon 2023; 9:e22323. [PMID: 38045215 PMCID: PMC10692899 DOI: 10.1016/j.heliyon.2023.e22323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 12/05/2023] Open
Abstract
Introduction Subcortical band heterotopia (SBH) is a rare brain developmental malformation caused by deficient neuronal migration during embryogenesis. Published literature on pediatric SBH cases caused by DCX mutations is limited. Methods The detailed clinical and genetic features of two pediatric SBH with DCX mutations were analyzed. The available literature on DCX mutations was reviewed. Results Both patients were girls with varying degrees of developmental delay. Patient 1 was short in stature with peculiar facial features. Patient 2 had an early seizure onset and developed drug-resistant epilepsy. Whole-exome sequencing (WES) revealed two de novo heterozygous variants of DCX (NM_178153.3), including a novel missense variant of c.568A > G (p.K190E) in P1 and a reported nonsense variant of c.814C > T (p.R272*) in P2. We reviewed all the available literature regarding DCX mutations. A total of 153 different mutations have been reported, with the majority of 99 (64.7 %) being missense mutations. Conclusion Our study expanded the mutational spectrum of DCX, which has important implications for the study of genotype-phenotype correlations. Furthermore, it provided insights to better understand SBH and genetic counseling.
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Affiliation(s)
- Chunlai Gao
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
| | - Ning Liu
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Jian Ma
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Jianshe Zhao
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Bing Zhao
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Fengling Song
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Rui Dong
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Zilong Li
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Yuqiang Lv
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Yi Liu
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
| | - Zhongtao Gai
- Children's Hospital Affiliated to Shandong University, Jinan, Shandong 250022, China
- Jinan Children's Hospital, Jinan, Shandong 250022, China
- Shandong Provincial Clinical Research Center for Children's Health and Disease, Jinan, Shandong 250022, China
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Ben-Mahmoud A, Kishikawa S, Gupta V, Leach NT, Shen Y, Moldovan O, Goel H, Hopper B, Ranguin K, Gruchy N, Maas SM, Lacassie Y, Kim SH, Kim WY, Quade BJ, Morton CC, Kim CH, Layman LC, Kim HG. A cryptic microdeletion del(12)(p11.21p11.23) within an unbalanced translocation t(7;12)(q21.13;q23.1) implicates new candidate loci for intellectual disability and Kallmann syndrome. Sci Rep 2023; 13:12984. [PMID: 37563198 PMCID: PMC10415337 DOI: 10.1038/s41598-023-40037-4] [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: 02/10/2023] [Accepted: 08/03/2023] [Indexed: 08/12/2023] Open
Abstract
In a patient diagnosed with both Kallmann syndrome (KS) and intellectual disability (ID), who carried an apparently balanced translocation t(7;12)(q22;q24)dn, array comparative genomic hybridization (aCGH) disclosed a cryptic heterozygous 4.7 Mb deletion del(12)(p11.21p11.23), unrelated to the translocation breakpoint. This novel discovery prompted us to consider the possibility that the combination of KS and neurological disorder in this patient could be attributed to gene(s) within this specific deletion at 12p11.21-12p11.23, rather than disrupted or dysregulated genes at the translocation breakpoints. To further support this hypothesis, we expanded our study by screening five candidate genes at both breakpoints of the chromosomal translocation in a cohort of 48 KS patients. However, no mutations were found, thus reinforcing our supposition. In order to delve deeper into the characterization of the 12p11.21-12p11.23 region, we enlisted six additional patients with small copy number variations (CNVs) and analyzed eight individuals carrying small CNVs in this region from the DECIPHER database. Our investigation utilized a combination of complementary approaches. Firstly, we conducted a comprehensive phenotypic-genotypic comparison of reported CNV cases. Additionally, we reviewed knockout animal models that exhibit phenotypic similarities to human conditions. Moreover, we analyzed reported variants in candidate genes and explored their association with corresponding phenotypes. Lastly, we examined the interacting genes associated with these phenotypes to gain further insights. As a result, we identified a dozen candidate genes: TSPAN11 as a potential KS candidate gene, TM7SF3, STK38L, ARNTL2, ERGIC2, TMTC1, DENND5B, and ETFBKMT as candidate genes for the neurodevelopmental disorder, and INTS13, REP15, PPFIBP1, and FAR2 as candidate genes for KS with ID. Notably, the high-level expression pattern of these genes in relevant human tissues further supported their candidacy. Based on our findings, we propose that dosage alterations of these candidate genes may contribute to sexual and/or cognitive impairments observed in patients with KS and/or ID. However, the confirmation of their causal roles necessitates further identification of point mutations in these candidate genes through next-generation sequencing.
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Affiliation(s)
- Afif Ben-Mahmoud
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Shotaro Kishikawa
- Gene Engineering Division, RIKEN BioResource Research Center, Tsukuba, Japan
| | - Vijay Gupta
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Natalia T Leach
- Integrated Genetics, Laboratory Corporation of America Holdings, 3400 Computer Drive, Westborough, MA, 01581, USA
| | - Yiping Shen
- Division of Genetics and Genomics at Boston Children's Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Oana Moldovan
- Medical Genetics Service, Pediatric Department, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Himanshu Goel
- Hunter Genetics, Waratah, NSW, 2298, Australia
- University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Bruce Hopper
- Forster Genetics-Hunter New England Local Health District, Forster, NSW, 2428, Australia
| | - Kara Ranguin
- Department of Genetics, Reference Center for Rare Diseases of Developmental anomalies and polymalformative syndrome, CHU de Caen Normandie, Caen, France
| | - Nicolas Gruchy
- Department of Genetics, Reference Center for Rare Diseases of Developmental anomalies and polymalformative syndrome, CHU de Caen Normandie, Caen, France
| | - Saskia M Maas
- Department of Human Genetics, Amsterdam University Medical Center, Amsterdam, the Netherlands
- Reproduction and Development Research Institute, University of Amsterdam, Amsterdam, the Netherlands
| | - Yves Lacassie
- Division of Genetics, Department of Pediatrics, Louisiana State University, New Orleans, LA, 70118, USA
| | - Soo-Hyun Kim
- Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, UK
| | - Woo-Yang Kim
- Department of Biological Sciences, Kent State University, Kent, OH, 44242, USA
| | - Bradley J Quade
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Cynthia C Morton
- Departments of Obstetrics and Gynecology and of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, 34134, Korea
| | - Lawrence C Layman
- Section of Reproductive Endocrinology, Infertility and Genetics, Department of Obstetrics and Gynecology, Augusta University, Augusta, GA, USA
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA, USA
| | - Hyung-Goo Kim
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar.
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
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Ben-Mahmoud A, Kishikawa S, Gupta V, Leach NT, Shen Y, Moldovan O, Goel H, Hopper B, Ranguin K, Gruchy N, Maas SM, Lacassie Y, Kim SH, Kim WY, Quade BJ, Morton CC, Kim CH, Layman LC, Kim HG. A microdeletion del(12)(p11.21p11.23) with a cryptic unbalanced translocation t(7;12)(q21.13;q23.1) implicates new candidate loci for intellectual disability and Kallmann syndrome. RESEARCH SQUARE 2023:rs.3.rs-2572736. [PMID: 37034680 PMCID: PMC10081357 DOI: 10.21203/rs.3.rs-2572736/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
In an apparently balanced translocation t(7;12)(q22;q24)dn exhibiting both Kallmann syndrome (KS) and intellectual disability (ID), we detected a cryptic heterozygous 4.7 Mb del(12)(p11.21p11.23) unrelated to the translocation breakpoint. This new finding raised the possibility that KS combined with neurological disorder in this patient could be caused by gene(s) within this deletion at 12p11.21-12p11.23 instead of disrupted or dysregulated genes at the genomic breakpoints. Screening of five candidate genes at both breakpoints in 48 KS patients we recruited found no mutation, corroborating our supposition. To substantiate this hypothesis further, we recruited six additional subjects with small CNVs and analyzed eight individuals carrying small CNVs in this region from DECIPHER to dissect 12p11.21-12p11.23. We used multiple complementary approaches including a phenotypic-genotypic comparison of reported cases, a review of knockout animal models recapitulating the human phenotypes, and analyses of reported variants in the interacting genes with corresponding phenotypes. The results identified one potential KS candidate gene ( TSPAN11 ), seven candidate genes for the neurodevelopmental disorder ( TM7SF3 , STK38L , ARNTL2 , ERGIC2 , TMTC1 , DENND5B , and ETFBKMT ), and four candidate genes for KS with ID ( INTS13 , REP15 , PPFIBP1 , and FAR2 ). The high-level expression pattern in the relevant human tissues further suggested the candidacy of these genes. We propose that the dosage alterations of the candidate genes may contribute to sexual and/or cognitive impairment in patients with KS and/or ID. Further identification of point mutations through next generation sequencing will be necessary to confirm their causal roles.
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Affiliation(s)
| | | | | | | | | | - Oana Moldovan
- Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte
| | | | - Bruce Hopper
- Forster Genetics-Hunter New England Local Health District
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Papadopoulou E, Pepe G, Konitsiotis S, Chondrogiorgi M, Grigoriadis N, Kimiskidis VK, Tsivgoulis G, Mitsikostas DD, Chroni E, Domouzoglou E, Tsaousis G, Nasioulas G. The evolution of comprehensive genetic analysis in neurology: Implications for precision medicine. J Neurol Sci 2023; 447:120609. [PMID: 36905813 DOI: 10.1016/j.jns.2023.120609] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/07/2023]
Abstract
Technological advancements have facilitated the availability of reliable and thorough genetic analysis in many medical fields, including neurology. In this review, we focus on the importance of selecting the appropriate genetic test to aid in the accurate identification of disease utilizing currently employed technologies for analyzing monogenic neurological disorders. Moreover, the applicability of comprehensive analysis via NGS for various genetically heterogeneous neurological disorders is reviewed, revealing its efficiency in clarifying a frequently cloudy diagnostic picture and delivering a conclusive and solid diagnosis that is essential for the proper management of the patient. The feasibility and effectiveness of medical genetics in neurology require interdisciplinary cooperation among several medical specialties and geneticists, to select and perform the most relevant test according to each patient's medical history, using the most appropriate technological tools. The prerequisites for a comprehensive genetic analysis are discussed, highlighting the utility of appropriate gene selection, variant annotation, and classification. Moreover, genetic counseling and interdisciplinary collaboration could improve diagnostic yield further. Additionally, a sub-analysis is conducted on the 1,502,769 variation records with submitted interpretations in the Clinical Variation (ClinVar) database, with a focus on neurology-related genes, to clarify the value of suitable variant categorization. Finally, we review the current applications of genetic analysis in the diagnosis and personalized management of neurological patients and the advances in the research and scientific knowledge of hereditary neurological disorders that are evolving the utility of genetic analysis towards the individualization of the treatment strategy.
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Affiliation(s)
| | - Georgia Pepe
- GeneKor Medical SA, Spaton 52, Gerakas 15344, Greece
| | - Spiridon Konitsiotis
- Department of Neurology, University of Ioannina, Stavrou Niarchou Avenue, Ioannina 45500, Greece
| | - Maria Chondrogiorgi
- Department of Neurology, University of Ioannina, Stavrou Niarchou Avenue, Ioannina 45500, Greece
| | - Nikolaos Grigoriadis
- Second Department of Neurology, "AHEPA" University Hospital, Aristotle University of Thessaloniki, St. Kiriakidis 1, Thessaloniki 54636, Greece
| | - Vasilios K Kimiskidis
- First Department of Neurology, "AHEPA" University hospital, Aristotle University of Thessaloniki, St. Kiriakidis 1, Thessaloniki 54636, Greece
| | - Georgios Tsivgoulis
- Second Department of Neurology, School of Medicine, "Attikon" University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Dimos D Mitsikostas
- First Department of Neurology, Aeginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Elisabeth Chroni
- Department of Neurology, School of Medicine, University of Patras, Rio-Patras, Greece
| | - Eleni Domouzoglou
- Department of Pediatrics, University Hospital of Ioannina, Stavrou Niarchou Avenue, Ioannina 45500, Greece
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