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Kharrat M, Triki C, Ben Isaa A, Bouchaala W, Alila O, Chouchen J, Ghouliya Y, Kamoun F, Tlili A, Fakhfakh F. Expanding the genetic and phenotypic spectrum of TRAPPC9 and MID2-related neurodevelopmental disabilities: report of two novel mutations, 3D-modelling, and molecular docking studies. J Hum Genet 2024; 69:291-299. [PMID: 38467738 DOI: 10.1038/s10038-024-01242-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/13/2024]
Abstract
Intellectual disabilities (ID) and autism spectrum disorders (ASD) have a variety of etiologies, including environmental and genetic factors. Our study reports a psychiatric clinical investigation and a molecular analysis using whole exome sequencing (WES) of two siblings with ID and ASD from a consanguineous family. Bioinformatic prediction and molecular docking analysis were also carried out. The two patients were diagnosed with profound intellectual disability, brain malformations such as cortical atrophy, acquired microcephaly, and autism level III. The neurological and neuropsychiatric examination revealed that P2 was more severely affected than P1, as he was unable to walk, presented with dysmorphic feature and exhibited self and hetero aggressive behaviors. The molecular investigations revealed a novel TRAPPC9 biallelic nonsense mutation (c.2920 C > T, p.R974X) in the two siblings. The more severely affected patient (P2) presented, along with the TRAPPC9 variant, a new missense mutation c.166 C > T (p.R56C) in the MID2 gene at hemizygous state, while his sister P1 was merely a carrier. The 3D modelling and molecular docking analysis revealed that c.166 C > T variant could affect the ability of MID2 binding to Astrin, leading to dysregulation of microtubule dynamics and causing morphological abnormalities in the brain. As our knowledge, the MID2 mutation (p.R56C) is the first one to be detected in Tunisia and causing phenotypic variability between the siblings. We extend the genetic and clinical spectrum of TRAPPC9 and MID2 mutations and highlights the possible concomitant presence of X-linked as well as autosomal recessive inheritance to causing ID, microcephaly, and autism.
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Affiliation(s)
- Marwa Kharrat
- Laboratory of Molecular and Functional Genetics, Faculty of Sciences of Sfax University, Sfax, Tunisia.
| | - Chahnez Triki
- Child Neurology Department, Hedi Chaker Hospital, Sfax, Tunisia
- Research laboratory (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
| | - Abir Ben Isaa
- Child Neurology Department, Hedi Chaker Hospital, Sfax, Tunisia
- Research laboratory (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
| | - Wafa Bouchaala
- Child Neurology Department, Hedi Chaker Hospital, Sfax, Tunisia
- Research laboratory (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
| | - Olfa Alila
- Laboratory of Molecular and Functional Genetics, Faculty of Sciences of Sfax University, Sfax, Tunisia
| | - Jihen Chouchen
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
| | - Yosra Ghouliya
- Child Neurology Department, Hedi Chaker Hospital, Sfax, Tunisia
- Research laboratory (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
| | - Fatma Kamoun
- Child Neurology Department, Hedi Chaker Hospital, Sfax, Tunisia
- Research laboratory (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates
| | - Faiza Fakhfakh
- Laboratory of Molecular and Functional Genetics, Faculty of Sciences of Sfax University, Sfax, Tunisia.
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Rochmah YS, Harumsari S, Christiono S, Hutami IR, Fatimah-Muis S, Faradz SM. Analysis of Consanguinity as Risk Factor of Nonsyndromic Cleft Lips with or without Palate. Eur J Dent 2024; 18:598-603. [PMID: 37995730 PMCID: PMC11132758 DOI: 10.1055/s-0043-1774334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023] Open
Abstract
OBJECTIVES The etiologies of nonsyndromic cleft lips with or without palate (NS CL/P) are multifactorial, which include consanguineous marriages. The incidence of NS CL/P is relatively high in Indonesia notably in one of Indonesia's tribes whose members frequently marry close cousins. Thus, the purpose of this study is to analysis consanguinity as risk factor of NS CL/P in Sasak tribe, East Lombok, Indonesia MATERIALS AND METHODS: An observational analysis was made of a collected database of NS CL/P patients treated in social services in regency hospital of Dr. Soejono Selong, East Lombok, Indonesia. Demographic data such as age, gender, address (urban/rural), parent's education, presence or absence of consanguinity, type of clefts, and a three-generation pedigree were collected by interview and hospital medical record. Before analysis, patient information was anonymized and deidentified. From 2016 to 2018, each of 100 cleft and normal subjects with their Sasak parent were audited. The risk factors were analyzed statistically using odds ratio (OR) and chi-squared test. RESULTS Consanguineous marriages identified 54 cases (54%), and 10 cases (10%) out of a total each 100 NS CL/P and controls, respectively. The majority of consanguinity (53.7%) was discovered in marriages between first cousins. NS CL/P cases were statistically linked (p = 0.00) with consanguineous marriages (OR: 10; 95% confidence interval: 1.6-3.1); in which the most prevalent case is unilateral cleft lips. CONCLUSION Consanguineous marriage increases the risk of NS CL/P in Sasak tribe, East Lombok, Indonesia. The development of strategies to educate communities on the impacts of culture-consanguineous marriage is required. The genetic inheritance from their ancestor may be responsible for the increased incidence of NS CL/P.
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Affiliation(s)
- Yayun Siti Rochmah
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Universitas Islam Sultan Agung, Semarang, Indonesia
| | - Stefani Harumsari
- Department of Medical Biology, Faculty of Medicine, Universitas Islam Sultan Agung, Semarang, Indonesia
| | - Sandy Christiono
- Department of Pediatric Dentistry, Faculty of Dentistry, Universitas Islam Sultan Agung, Semarang, Indonesia
| | - Islamy Rahma Hutami
- Department of Orthodontics, Faculty of Dentistry, Universitas Islam Sultan Agung, Semarang, Indonesia
| | - Siti Fatimah-Muis
- Department of Nutrition, Faculty of Medicine, Universitas Diponegoro, Semarang, Indonesia
| | - Sultana M.H. Faradz
- Center for Biomedical Research (CEBIOR), Faculty of Medicine, Universitas Diponegoro, Semarang, Indonesia
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Uctepe E, Yesilyurt A, Esen FN, Tumer S, Mancilar H, Sonmez FM. TRAPPC9-Related Intellectual Disability: Report of Two New Cases and Review of the Literature. Mol Syndromol 2023; 14:485-492. [PMID: 38058760 PMCID: PMC10697769 DOI: 10.1159/000531439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 06/05/2023] [Indexed: 12/08/2023] Open
Abstract
Introduction Hereditary forms of intellectual disability (ID), an estimated prevalence ranging between 1% and 3% in the general population, are among the most important problems in health care. Especially, autosomal-recessive ID has a very heterogeneous molecular basis and a lack of specific phenotypic features. Methods Here, we report on two unrelated patients with autosomal-recessive ID, microcephaly, and autistic features and review the patients with TRAPPC9-related ID. Whole-exome sequencing and array CGH were performed for molecular diagnosis of the patients. Results The first case has a microdeletion on chromosome 8q24.23-q24.3 region which is 1.7 Mb in length and includes the last 5 exons of TRAPPC9, and c.3435delG [p.Thr1146Profs*8] deletion. The second case has a homozygous missense c.623A>C (p.His208Pro) variant in TRAPPC9 which is detected by means of whole-exome sequencing study of the proband. We also reviewed the clinical findings and mutation spectrum of all patients with TRAPPC9-related ID reported so far. Conclusions Our study showed that the most consistent clinical findings for TRAPPC9-related ID are ID, microcephaly, and some structural brain MRI abnormalities. The mutations in the TRAPPC9 are scattered throughout all exons of TRAPPC9 indicating there is no hot spot mutation region in this gene.
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Affiliation(s)
- Eyyup Uctepe
- Acibadem Ankara Tissue Typing Laboratory, Ankara, Turkey
| | - Ahmet Yesilyurt
- Acibadem Labgen Genetic Diagnosis Center, Istanbul, Turkey
- Acibadem Maslak Hospital, Istanbul, Turkey
| | | | - Sait Tumer
- Acibadem Labgen Genetic Diagnosis Center, Istanbul, Turkey
| | | | - Fatma Mujgan Sonmez
- Karadeniz Technical University Faculty of Medicine, Department of Child Neurology, Ankara, Turkey
- Private office, Child Neurology, Ankara, Turkey
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Loftus D, Bae B, Whilden CM, Whipple AJ. Allelic chromatin structure precedes imprinted expression of Kcnk9 during neurogenesis. Genes Dev 2023; 37:829-843. [PMID: 37821107 PMCID: PMC10620047 DOI: 10.1101/gad.350896.123] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/18/2023] [Indexed: 10/13/2023]
Abstract
Differences in chromatin state inherited from the parental gametes influence the regulation of maternal and paternal alleles in offspring. This phenomenon, known as genomic imprinting, results in genes preferentially transcribed from one parental allele. While local epigenetic factors such as DNA methylation are known to be important for the establishment of imprinted gene expression, less is known about the mechanisms by which differentially methylated regions (DMRs) lead to differences in allelic expression across broad stretches of chromatin. Allele-specific higher-order chromatin structure has been observed at multiple imprinted loci, consistent with the observation of allelic binding of the chromatin-organizing factor CTCF at multiple DMRs. However, whether allelic chromatin structure impacts allelic gene expression is not known for most imprinted loci. Here we characterize the mechanisms underlying brain-specific imprinted expression of the Peg13-Kcnk9 locus, an imprinted region associated with intellectual disability. We performed region capture Hi-C on mouse brains from reciprocal hybrid crosses and found imprinted higher-order chromatin structure caused by the allelic binding of CTCF to the Peg13 DMR. Using an in vitro neuron differentiation system, we showed that imprinted chromatin structure precedes imprinted expression at the locus. Additionally, activation of a distal enhancer induced imprinted expression of Kcnk9 in an allelic chromatin structure-dependent manner. This work provides a high-resolution map of imprinted chromatin structure and demonstrates that chromatin state established in early development can promote imprinted expression upon differentiation.
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Affiliation(s)
- Daniel Loftus
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Bongmin Bae
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Courtney M Whilden
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Amanda J Whipple
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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Loftus D, Bae B, Whilden CM, Whipple AJ. Allelic chromatin structure primes imprinted expression of Kcnk9 during neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.09.544389. [PMID: 37333073 PMCID: PMC10274912 DOI: 10.1101/2023.06.09.544389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Differences in chromatin state inherited from the parental gametes influence the regulation of maternal and paternal alleles in offspring. This phenomenon, known as genomic imprinting, results in genes preferentially transcribed from one parental allele. While local epigenetic factors such as DNA methylation are known to be important for the establishment of imprinted gene expression, less is known about the mechanisms by which differentially methylated regions (DMRs) lead to differences in allelic expression across broad stretches of chromatin. Allele-specific higher-order chromatin structure has been observed at multiple imprinted loci, consistent with the observation of allelic binding of the chromatin-organizing factor CTCF at multiple DMRs. However, whether allelic chromatin structure impacts allelic gene expression is not known for most imprinted loci. Here we characterize the mechanisms underlying brain-specific imprinted expression of the Peg13-Kcnk9 locus, an imprinted region associated with intellectual disability. We performed region capture Hi-C on mouse brain from reciprocal hybrid crosses and found imprinted higher-order chromatin structure caused by the allelic binding of CTCF to the Peg13 DMR. Using an in vitro neuron differentiation system, we show that on the maternal allele enhancer-promoter contacts formed early in development prime the brain-specific potassium leak channel Kcnk9 for maternal expression prior to neurogenesis. In contrast, these enhancer-promoter contacts are blocked by CTCF on the paternal allele, preventing paternal Kcnk9 activation. This work provides a high-resolution map of imprinted chromatin structure and demonstrates that chromatin state established in early development can promote imprinted expression upon differentiation.
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Affiliation(s)
- Daniel Loftus
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 USA
| | - Bongmin Bae
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 USA
| | - Courtney M. Whilden
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 USA
| | - Amanda J. Whipple
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 USA
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Penon-Portmann M, Hodoglugil U, Arun P W, Yip T, Slavotinek A, Tenney JL. TRAPPC9-related neurodevelopmental disorder: Report of a homozygous deletion in TRAPPC9 due to paternal uniparental isodisomy. Am J Med Genet A 2023; 191:1077-1082. [PMID: 36574751 DOI: 10.1002/ajmg.a.63100] [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: 08/06/2022] [Revised: 10/24/2022] [Accepted: 12/11/2022] [Indexed: 12/28/2022]
Abstract
TRAPPC9 loss-of-function biallelic variants are associated with an autosomal recessive intellectual disability syndrome (Online Mendelian Inheritance of Man no. 613192), also characterized by microcephaly, hypertelorism, obesity, growth delay, and behavioral differences. Here, we describe an 8-year-old Hispanic female with neurodevelopmental disorder, partial epilepsy, microcephaly, bilateral cleft lip and alveolus, growth delay, and dysmorphic features. She had abnormal myelination, mega cisterna magna, and colpocephaly on brain magnetic resonance imaging (MRI). Microarray showed a single ~146 Mb region of homozygosity (ROH) encompassing all of Chromosome 8, consistent with uniparental isodisomy (UPD). Exome sequencing performed in-house did not identify single nucleotide variants to explain her phenotype. Algorithms developed in-house and further evaluation of BAM files revealed a homozygous deletion overlapping Exon 2 in TRAPPC9 within the ROH. Subsequent del/dup analyses with exon-level oligo array confirmed a likely pathogenic deletion in TRAPPC9 (NM_031466.5): arr[GRCh37] 8q24.3(141460661_141461780)x0. Our case highlights the implications of downstream analyses from UPD/ROH given the increased risk for AR conditions, the strengths of combining orthologous molecular methods to establish a diagnosis and further delineates the TRAPPC9-related phenotype in an individual of Hispanic ancestry.
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Affiliation(s)
- Monica Penon-Portmann
- Division of Medical Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, USA.,Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Ugur Hodoglugil
- Genomic Medicine Laboratory, University of California San Francisco, San Francisco, California, USA
| | - Wiita Arun P
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, California, USA
| | - Tiffany Yip
- Institute for Human Genetics, University of California San Francisco, San Francisco, California, USA
| | - Anne Slavotinek
- Division of Medical Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, USA.,Division of Human Genetics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jessica L Tenney
- Division of Medical Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
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Dattilo V, Ulivi S, Minelli A, La Bianca M, Giacopuzzi E, Bortolomasi M, Bignotti S, Gennarelli M, Gasparini P, Concas MP. Genome-wide association studies on Northern Italy isolated populations provide further support concerning genetic susceptibility for major depressive disorder. World J Biol Psychiatry 2023; 24:135-148. [PMID: 35615967 DOI: 10.1080/15622975.2022.2082523] [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] [Indexed: 10/18/2022]
Abstract
OBJECTIVES Major depressive disorder (MDD) is a psychiatric disorder with pathogenesis influenced by both genetic and environmental factors. To date, the molecular-level understanding of its aetiology remains unclear. Thus, we aimed to identify genetic variants and susceptibility genes for MDD with a genome-wide association study (GWAS) approach. METHODS We performed a meta-analysis of GWASs and a gene-based analysis on two Northern Italy isolated populations (cases/controls n = 166/472 and 33/320), followed by replication and polygenic risk score (PRS) analyses in Italian independent samples (cases n = 464, controls n = 339). RESULTS We identified two novel MDD-associated genes, KCNQ5 (lead SNP rs867262, p = 3.82 × 10-9) and CTNNA2 (rs6729523, p = 1.25 × 10-8). The gene-based analysis revealed another six genes (p < 2.703 × 10-6): GRM7, CTNT4, SNRK, SRGAP3, TRAPPC9, and FHIT. No replication of the genome-wide significant SNPs was found in the independent cohort, even if 14 SNPs around CTNNA2 showed association with MDD and related phenotypes at the nominal level of p (<0.05). Furthermore, the PRS model developed in the discovery cohort discriminated cases and controls in the replication cohort. CONCLUSIONS Our work suggests new possible genes associated with MDD, and the PRS analysis confirms the polygenic nature of this disorder. Future studies are required to better understand the role of these findings in MDD.
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Affiliation(s)
- Vincenzo Dattilo
- Genetics Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Sheila Ulivi
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy
| | - Alessandra Minelli
- Genetics Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.,Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Martina La Bianca
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy
| | - Edoardo Giacopuzzi
- Wellcome Centre for Human Genetics, Oxford University, Oxford, UK.,NIHR Oxford Biomedical Research Centre, Oxford, UK
| | | | - Stefano Bignotti
- Unit of Psychiatry, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Massimo Gennarelli
- Genetics Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.,Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Paolo Gasparini
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy.,Department of Medicine, Surgery and Health Science, University of Trieste, Trieste, Italy
| | - Maria Pina Concas
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy
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Abstract
Vesicles mediate the trafficking of membranes/proteins in the endocytic and secretory pathways. These pathways are regulated by small GTPases of the Rab family. Rab proteins belong to the Ras superfamily of GTPases, which are significantly involved in various intracellular trafficking and signaling processes in the nervous system. Rab11 is known to play a key role especially in recycling many proteins, including receptors important for signal transduction and preservation of functional activities of nerve cells. Rab11 activity is controlled by GEFs (guanine exchange factors) and GAPs (GTPase activating proteins), which regulate its function through modulating GTP/GDP exchange and the intrinsic GTPase activity, respectively. Rab11 is involved in the transport of several growth factor molecules important for the development and repair of neurons. Overexpression of Rab11 has been shown to significantly enhance vesicle trafficking. On the other hand, a reduced expression of Rab11 was observed in several neurodegenerative diseases. Current evidence appears to support the notion that Rab11 and its cognate proteins may be potential targets for therapeutic intervention. In this review, we briefly discuss the function of Rab11 and its related interaction partners in intracellular pathways that may be involved in neurodegenerative processes.
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Affiliation(s)
| | - Jiri Novotny
- Jiri Novotny, Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic.
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Amin M, Vignal C, Eltaraifee E, Mohammed IN, Hamed AAA, Elseed MA, Babai A, Elbadi I, Mustafa D, Abubaker R, Mustafa M, Drunat S, Elsayed LEO, Ahmed AE, Boespflug-Tanguy O, Dorboz I. A novel homozygous mutation in TRAPPC9 gene causing autosomal recessive non-syndromic intellectual disability. BMC Med Genomics 2022; 15:236. [PMID: 36348459 PMCID: PMC9644490 DOI: 10.1186/s12920-022-01354-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 09/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background The etiology of intellectual disabilities is diverse and includes both genetic and environmental factors. The genetic causes of intellectual disabilities range from chromosomal aberrations to single gene disorders. The TRAPPC9 gene has been reported to cause autosomal recessive forms of intellectual disabilities in 56 patients from consanguineous and non-consanguineous families around the world. Methods We analyzed two siblings with intellectual disability, microcephaly and delayed motor and speech development from a consanguineous Sudanese family. Genomic DNA was screened for mutations using NGS panel (NextSeq500 Illumina) testing 173 microcephaly associated genes in the Molecular Genetics service in Robert Debre hospital in Paris, France. Results A novel homozygous mutation (NM_031466.7 (TRAPPC9):c.2288dup, p. (Val764Glyfs*7) in exon 14 of TRAPPC9 gene was found in the two patients. The mutation was predicted to cause nonsense mediated decay (NSMD) using SIFT prediction tool. The variant has not been found in either gnomAD or Exac databases. Both parents were heterozygous (carriers) to the mutation. Conclusion This is the first study to report patients with TRAPPC9-related disorder from Sub-Saharan Africa.
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TRAPPC9-CDG: A novel congenital disorder of glycosylation with dysmorphic features and intellectual disability. Genet Med 2022; 24:894-904. [PMID: 35042660 DOI: 10.1016/j.gim.2021.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 02/07/2023] Open
Abstract
PURPOSE TRAPPC9 deficiency is an autosomal recessive disorder mainly associated with intellectual disability (ID), microcephaly, and obesity. Previously, TRAPPC9 deficiency has not been associated with biochemical abnormalities. METHODS Exome sequencing was performed in 3 individuals with ID and dysmorphic features. N-Glycosylation analyses were performed in the patients' blood samples to test for possible congenital disorder of glycosylation (CDG). TRAPPC9 gene, TRAPPC9 protein expression, and N-glycosylation markers were assessed in patient fibroblasts. Complementation with wild-type TRAPPC9 and immunofluorescence studies to assess TRAPPC9 expression and localization were performed. The metabolic consequences of TRAPPC9 deficiency were evaluated using tracer metabolomics. RESULTS All 3 patients carried biallelic missense variants in TRAPPC9 and presented with an N-glycosylation defect in blood, consistent with CDG type I. Extensive investigations in patient fibroblasts corroborated TRAPPC9 deficiency and an N-glycosylation defect. Tracer metabolomics revealed global metabolic changes with several affected glycosylation-related metabolites. CONCLUSION We identified 3 TRAPPC9 deficient patients presenting with ID, dysmorphic features, and abnormal glycosylation. On the basis of our findings, we propose that TRAPPC9 deficiency could lead to a CDG (TRAPPC9-CDG). The finding of abnormal glycosylation in these patients is highly relevant for diagnosis, further elucidation of the pathophysiology, and management of the disease.
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Rawlins LE, Almousa H, Khan S, Collins SC, Milev MP, Leslie J, Saint-Dic D, Khan V, Hincapie AM, Day JO, McGavin L, Rowley C, Harlalka GV, Vancollie VE, Ahmad W, Lelliott CJ, Gul A, Yalcin B, Crosby AH, Sacher M, Baple EL. Biallelic variants in TRAPPC10 cause a microcephalic TRAPPopathy disorder in humans and mice. PLoS Genet 2022; 18:e1010114. [PMID: 35298461 PMCID: PMC8963566 DOI: 10.1371/journal.pgen.1010114] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 03/29/2022] [Accepted: 02/20/2022] [Indexed: 11/25/2022] Open
Abstract
The highly evolutionarily conserved transport protein particle (TRAPP) complexes (TRAPP II and III) perform fundamental roles in subcellular trafficking pathways. Here we identified biallelic variants in TRAPPC10, a component of the TRAPP II complex, in individuals with a severe microcephalic neurodevelopmental disorder. Molecular studies revealed a weakened interaction between mutant TRAPPC10 and its putative adaptor protein TRAPPC2L. Studies of patient lymphoblastoid cells revealed an absence of TRAPPC10 alongside a concomitant absence of TRAPPC9, another key TRAPP II complex component associated with a clinically overlapping neurodevelopmental disorder. The TRAPPC9/10 reduction phenotype was recapitulated in TRAPPC10-/- knockout cells, which also displayed a membrane trafficking defect. Notably, both the reduction in TRAPPC9 levels and the trafficking defect in these cells could be rescued by wild type but not mutant TRAPPC10 gene constructs. Moreover, studies of Trappc10-/- knockout mice revealed neuroanatomical brain defects and microcephaly, paralleling findings seen in the human condition as well as in a Trappc9-/- mouse model. Together these studies confirm autosomal recessive TRAPPC10 variants as a cause of human disease and define TRAPP-mediated pathomolecular outcomes of importance to TRAPPC9 and TRAPPC10 mediated neurodevelopmental disorders in humans and mice. Microcephalic neurodevelopmental disorders are a group of conditions that are often inherited in families, involving small head size and abnormal brain development and function. This often results in delayed development of an affected child, affecting their movement, language and/or non-verbal communication and learning, as well as seizures and neuropsychiatric problems. A group of proteins called the transport protein particles (TRAPPs) are important for the transport of cargos inside cells. Alterations within a number of the TRAPP proteins have previously been associated with human inherited diseases called the ‘TRAPPopathies’, which involve neurodevelopmental and skeletal abnormalities. Here we show that TRAPPC10 gene alterations cause a new TRAPPopathy microcephalic neurodevelopmental disorder, and we provide a detailed clinical description of the condition termed ‘TRAPPC10-related disorder’. Our studies in mice lacking the TRAPPC10 gene identified similar features to those of affected humans, including small brain size and skeletal abnormalities. Our molecular studies showed that an affected individual with an alteration in the TRAPPC10 gene has no functional TRAPPC10 protein in their cells, which in turn causes a reduction in levels of another important TRAPP molecule, TRAPPC9. Cells lacking TRAPPC10 also display abnormalities in cellular transport processes. Together our data confirm alterations in TRAPPC10 as a cause of a microcephalic neurodevelopmental disorder in both humans and mice.
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Affiliation(s)
- Lettie E. Rawlins
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital (Heavitree), Exeter, United Kingdom
| | - Hashem Almousa
- Department of Biology, Concordia University, Montreal, Quebec, Canada
| | - Shazia Khan
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
- Department of Biological Sciences, International Islamic University, Islamabad, Pakistan
| | - Stephan C. Collins
- Institute of Genetics and Molecular and Cellular Biology, Inserm, Illkirch, France
- Inserm, University of Bourgogne Franche-Comté, Dijon, France
| | - Miroslav P. Milev
- Department of Biology, Concordia University, Montreal, Quebec, Canada
| | - Joseph Leslie
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
| | - Djenann Saint-Dic
- Department of Biology, Concordia University, Montreal, Quebec, Canada
| | - Valeed Khan
- Department of Molecular Diagnostics, Rehman Medical Institute, Peshawar, Pakistan
| | | | - Jacob O. Day
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
- Faculty of Health, University of Plymouth, Plymouth, United Kingdom
| | - Lucy McGavin
- University Hospitals Plymouth NHS Trust, Plymouth, United Kingdom
| | | | - Gaurav V. Harlalka
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
- Department of Pharmacology, Rajarshi Shahu College of Pharmacy, Malvihir, Buldana, India
| | | | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | | | - Asma Gul
- Department of Biological Sciences, International Islamic University, Islamabad, Pakistan
| | - Binnaz Yalcin
- Institute of Genetics and Molecular and Cellular Biology, Inserm, Illkirch, France
- Inserm, University of Bourgogne Franche-Comté, Dijon, France
| | - Andrew H. Crosby
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
| | - Michael Sacher
- Department of Biology, Concordia University, Montreal, Quebec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Emma L. Baple
- RILD Wellcome Wolfson Medical Research Centre, RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital (Heavitree), Exeter, United Kingdom
- * E-mail:
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12
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Biallelic loss of TRAPPC9 function links vesicle trafficking pathway to autosomal recessive intellectual disability. J Hum Genet 2022; 67:279-284. [PMID: 34983975 DOI: 10.1038/s10038-021-01007-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND The trafficking protein particle (TRAPP) complex subunit 9 (C9) protein is a member of TRAPP-II complexes and regulates vesicle trafficking. Biallelic mutations in the TRAPPC9 gene are responsible for intellectual disability with expanded developmental delay, epilepsy, microcephaly, and brain atrophy. TRAPPC9-related disease list is still expanding, however, the functional effects of only a limited fraction of these have been studied. METHODS In a patient with a pathological variant in TRAPPC9, clinical examination and cranial imaging findings were evaluated. Whole-exome sequencing, followed by Sanger sequencing was performed to detect and verify the variant. To confirm the functional effect of the mutation; variant mRNA and protein expression levels were evaluated by qRT-PCR and Western blotting. Immunostaining for TRAPPC9 and lipid droplet accumulation were examined. RESULTS We have identified a novel homozygous c.696C>G (p.Phe232Leu) pathogenic variant in TRAPPC9 (NM_031466.6) gene as a cause of severe developmental delay. Functional characterization of the TRAPPC9 variant resulted in decreased mRNA and protein expression. The intracellular findings showed that TRAPPC9 protein build-up around the nucleus in mutant type while there was no specific accumulation in the control cell line. This disrupted protein pattern affected the amount of neutral lipid-carrying vesicles and their homogenous distribution at a decreasing level. CONCLUSION Biallelic variants in the TRAPPC9 gene have been reported as the underlying cause of intellectual disability. This study provides functional evidence of the novel variant in TRAPPC9 We demonstrated that the loss of function variant exclusively targeting TRAPPC9 may explicate the neurological findings through vesicle trafficking.
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13
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Ben Ayed I, Bouchaala W, Bouzid A, Feki W, Souissi A, Ben Nsir S, Ben Said M, Sammouda T, Majdoub F, Kharrat I, Kamoun F, Elloumi I, Kamoun H, Tlili A, Masmoudi S, Triki C. Further insights into the spectrum phenotype of TRAPPC9 and CDK5RAP2 genes, segregating independently in a large Tunisian family with intellectual disability and microcephaly. Eur J Med Genet 2021; 64:104373. [PMID: 34737153 DOI: 10.1016/j.ejmg.2021.104373] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 10/06/2021] [Accepted: 10/27/2021] [Indexed: 10/20/2022]
Abstract
Intellectual disability (ID) often co-occurs with other neurologic phenotypes making molecular diagnosis more challenging particularly in consanguineous populations with the co-segregation of more than one ID-related gene in some cases. In this study, we investigated the phenotype of three patients from a large Tunisian family with significant ID phenotypic variability and microcephaly and performed a clinical exome sequencing in two cases. We identified, within the first branch, a homozygous variant in the TRAPPC9 gene (p.Arg472Ter) in two cases presenting severe ID, absent speech, congenital/secondary microcephaly in addition to autistic features, supporting the implication of TRAPPC9 in the "secondary" autism spectrum disorders and congenital microcephaly. In the second branch, we identified a homozygous variant (p.Lys189ArgfsTer15) in the CDK5RAP2 gene associated with an heterozygous TRAPPC9 variant (p.Arg472Ter) in one case harbouring primary hereditary microcephaly (MCPH) associated with an inter-hypothalamic adhesion, mixed hearing loss, selective thinning in the retinal nerve fiber layer and parafoveal ganglion cell complex, and short stature. Our findings expand the spectrum of the recently reported neurosensorial abnormalities and revealed the variable phenotype expressivity of CDK5RAP2 defect. Our study highlights the complexity of the genetic background of microcephaly/ID and the efficiency of the exome sequencing to provide an accurate diagnosis and to improve the management and follow-up of such patients.
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Affiliation(s)
- Ikhlas Ben Ayed
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Tunisia; Medical Genetics Department, University Hedi Chaker Hospital of Sfax, Tunisia.
| | - Wafa Bouchaala
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Tunisia; Research Laboratory "Neuropédiatrie" LR19ES15, Sfax University, Tunisia
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Tunisia; Medical Research, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates
| | - Wiem Feki
- Radiology Department, Hedi Chaker University Hospital, University of Sfax, Sfax, Tunisia
| | - Amal Souissi
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Sihem Ben Nsir
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Tunisia; Research Laboratory "Neuropédiatrie" LR19ES15, Sfax University, Tunisia
| | - Mariem Ben Said
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Takwa Sammouda
- Department of Ophthalmology, Habib Bourguiba Hospital, Sfax, Tunisia
| | - Fatma Majdoub
- Medical Genetics Department, University Hedi Chaker Hospital of Sfax, Tunisia
| | - Ines Kharrat
- Department of Otorhinolaryngology, University Habib Bourguiba Hospital of Sfax, Tunisia
| | - Fatma Kamoun
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Tunisia; Research Laboratory "Neuropédiatrie" LR19ES15, Sfax University, Tunisia
| | - Ines Elloumi
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Hassen Kamoun
- Medical Genetics Department, University Hedi Chaker Hospital of Sfax, Tunisia; Laboratory of Human Molecular Genetics, LR33ES99, Faculty of Medicine of Sfax, University of Sfax, Sfax, Tunisia
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates; Human Genetics and Stem Cell Laboratory, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, United Arab Emirates
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes (LPCMC), Center of Biotechnology of Sfax, University of Sfax, Tunisia
| | - Chahnez Triki
- Child Neurology Department, University Hedi Chaker Hospital of Sfax, Tunisia; Research Laboratory "Neuropédiatrie" LR19ES15, Sfax University, Tunisia
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14
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Devyatkin VA, Redina OE, Kolosova NG, Muraleva NA. Single-Nucleotide Polymorphisms Associated with the Senescence-Accelerated Phenotype of OXYS Rats: A Focus on Alzheimer's Disease-Like and Age-Related-Macular-Degeneration-Like Pathologies. J Alzheimers Dis 2021; 73:1167-1183. [PMID: 31929160 DOI: 10.3233/jad-190956] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Alzheimer's disease (AD) and age-related macular degeneration (AMD) are two complex incurable neurodegenerative disorders the common pathogenesis of which is actively discussed. There are overlapping risk factors and molecular mechanisms of the two diseases; at the same time, there are arguments in favor of the notion that susceptibility to each of these diseases is associated with a distinct genetic background. Here we identified single-nucleotide polymorphisms (SNPs) that are specific for senescence-accelerated OXYS rats, which simulate key characteristics of both sporadic AD and AMD. Transcriptomes of the hippocampus, prefrontal cortex, and retina (data of RNA-Seq) were analyzed. We detected SNPs in genes Rims2, AABR07072639.2, Lemd2, and AABR07045405.1, which thus can express significantly truncated proteins lacking functionally important domains. Additionally, 33 mutations in genes-which are related to various metabolic and signaling pathways-cause nonsynonymous amino acid substitutions presumably leading to disturbances in protein structure or functions. Some of the genes carrying these SNPs are associated with aging, neurodegenerative, and mental diseases. Thus, we revealed the SNPs can lead to abnormalities in protein structure or functions and affect the development of the senescence-accelerated phenotype of OXYS rats. Our data are consistent with the latest results of genome-wide association studies that highlight the importance of multiple pathways for the pathogenesis of AD and AMD. Identified SNPs can serve as promising research objects for further studies on the molecular mechanisms underlying this particular rat model as well as for the prediction of potential biomarkers of AD and AMD.
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Affiliation(s)
- Vasiliy A Devyatkin
- Institute of Cytology and Genetics, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | - Olga E Redina
- Institute of Cytology and Genetics, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
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15
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Novel Compound Heterozygous Mutation in TRAPPC9 Gene: The Relevance of Whole Genome Sequencing. Genes (Basel) 2021; 12:genes12040557. [PMID: 33921338 PMCID: PMC8068822 DOI: 10.3390/genes12040557] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 12/17/2022] Open
Abstract
Advances in high-throughput technologies and its implementation worldwide have had a considerable impact on the elucidation of the molecular causes underlying neurodevelopmental psychiatric disorders, especially for autism spectrum disorder and intellectual disability (ID). Nevertheless, etiology remains elusive in close to 50% of cases, even in those families with multiple affected individuals, strongly hinting at a genetic cause. Here we present a case report of two siblings affected with severe ID and other comorbidities, who embarked on a genetic testing odyssey until diagnosis was reached by using whole genome sequencing (WGS). WGS identified a maternally inherited novel missense variant (NM_031466.7:c.1037G > A; p.Gly346Glu) and a paternally inherited 90 kb intragenic deletion in TRAPPC9 gene. This report demonstrates the clinical utility of WGS in patients who remain undiagnosed after whole exome sequencing.
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16
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Rasool IG, Zahoor MY, Iqbal M, Anjum AA, Ashraf F, Abbas HQ, Baig HMA, Mahmood T, Shehzad W. Whole exome sequencing revealed novel variants in consanguineous Pakistani families with intellectual disability. Genes Genomics 2021; 43:503-512. [PMID: 33710595 DOI: 10.1007/s13258-021-01070-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 02/19/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND Intellectual disability (ID) is a heterogeneous disorder affecting 1-3% of the population. Elucidation of monogenic variants for ID is a current challenge. These variants can be better demonstrated in consanguineous affected families. OBJECTIVE The study was designed to find the genetic variants of ID in consanguineous families. METHODS We analyzed five unrelated consanguineous Pakistani families affected with ID using whole exome sequencing (WES). Data was analyzed using different bioinformatics tools and software. RESULTS We mapped four variants including three novels in four different ID known genes. Each variant is found in a different family, co-segregating with a recessive pattern of inheritance. The novel variants found are; c. 2_4del (p.?) mapped in ROS1 and c. 718G>A (p.Gly240Arg) in GRM1. Another novel causative variant, c.2673del (p.Gly892Aspfs*17) identified in COL18A1 in a recessive form, a gene reported for Knobloch syndrome that manifests ID along with typical retinal abnormalities, and this phenotype was confirmed on reverse phenotyping. A mutation c.2134C>T (p.Arg712*) in TRAPPC9 has been found first time in the homozygous recessive form in our enrolled three affected siblings while it was previously reported in compound heterozygous form in a Caucasian descent. While fifth family remained unsolved. CONCLUSION These mutations in four different genes with a recessive inheritance would be a contribution to the disease variant database of this devastating disorder.
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Affiliation(s)
- Iqra Ghulam Rasool
- Molecular Biology and Forensic Laboratory, Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan
| | - Muhammad Yasir Zahoor
- Molecular Biology and Forensic Laboratory, Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan.
| | - Muhammad Iqbal
- Department of Biotechnology, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Aftab Ahmad Anjum
- Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Fatima Ashraf
- Molecular Biology and Forensic Laboratory, Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan
| | - Hafiz Qamar Abbas
- Molecular Biology and Forensic Laboratory, Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan
| | | | - Tariq Mahmood
- Department of Statistics and Computer Science, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Wasim Shehzad
- Molecular Biology and Forensic Laboratory, Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, 54000, Pakistan
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17
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Krämer J, Beer M, Bode H, Winter B. Two Novel Compound Heterozygous Mutations in the TRAPPC9 Gene Reveal a Connection of Non-syndromic Intellectual Disability and Autism Spectrum Disorder. Front Genet 2021; 11:972. [PMID: 33719327 PMCID: PMC7947907 DOI: 10.3389/fgene.2020.00972] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/31/2020] [Indexed: 12/28/2022] Open
Abstract
Introduction Autism spectrum disorder (ASD) is characterized by deficits in communication, social interaction, and repetitive behavior. Up to 70% of ASD cases are linked with intellectual disability (ID). The major genetic causes for ASD and ID are largely unknown, however, a shared genetic etiology between ASD and ID must be assumed. The trafficking protein particle complex subunit 9 (TRAPPC9) is highly expressed in postmitotic neurons of the cerebral cortex, playing a key role in development. Among 43 reported cases with mutations in TRAPPC9, all (100%) showed ID and developmental delay. Among the cases including information about ASD, 26% were affected (19 cases with information, among them 5 with ASD). Nevertheless, in some cases not classified as ASD, descriptions of autistic features like hand-flapping movements were present. Clinical Findings The affected individual presented with delay of speech development. Physical development was normal. Besides lateral slope of the eye-lid axis no facial abnormalities were evident. The individual was diagnosed with ID and ASD by structured testing. Cerebral MRI revealed associated abnormalities. Genetical Findings The chromosome set was 46,XY without structural changes. Array-CGH showed a normal molecular karyotype (arr(1-22)x2,(X,Y)x1). PCR for the FMR1 gene showed 41 ± 1 CGG repeats, and therefore no evidence of fragile X syndrome. A panel diagnostic for syndromal ID (CASK, EP300, HIVEP2, KIF1A, TRAPPC9) revealed two structural changes in TRAPPC9 in the compound heterozygosity. The mutations c.1678C > T (p.Arg560Cys) and c.3370C > T (p.Pro1124Ser) are classified as missense mutations and are both not described in the literature. Conclusion We report two new missense mutations in the TRAPPC9 gene in one individual with ID and ASD. The TRAPPC9 gene should be part of the diagnostic assessment in ID. ASD must be considered as a feature of TRAPPC9-associated ID. It might have been neglected in the literature and should result in specific testing for ASD in affected individuals.
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Affiliation(s)
- Johannes Krämer
- Division of Pediatric Neurology and Inborn Errors of Metabolism, Children's Hospital, Ulm University, Ulm, Germany
| | - Meinrad Beer
- Department of Radiology, Ulm University, Ulm, Germany
| | - Harald Bode
- Division of Pediatric Neurology and Inborn Errors of Metabolism, Children's Hospital, Ulm University, Ulm, Germany
| | - Benedikt Winter
- Division of Pediatric Neurology and Inborn Errors of Metabolism, Children's Hospital, Ulm University, Ulm, Germany
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18
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Yousefipour F, Mozhdehipanah H, Mahjoubi F. Identification of two novel homozygous nonsense mutations in TRAPPC9 in two unrelated consanguineous families with intellectual Disability from Iran. Mol Genet Genomic Med 2021; 9:e1610. [PMID: 33513295 PMCID: PMC8683625 DOI: 10.1002/mgg3.1610] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 11/12/2022] Open
Abstract
Background Pathogenic mutations in TRAPPC9 are associated with autosomal recessive Intellectual Disability (ID), a major public health issue that affects about 1–3% of children worldwide. Method Clinical evaluation, magnetic resonance imaging, peripheral blood karyotype, Multiplex ligation‐dependent probe amplification (MLPA), array CGH, and whole‐exome sequencing were used to characterize etiology in three patients from two unrelated consanguineous families of Iranian descent with intellectual disability. Results Whole‐exome sequencing showed two novel homozygous nonsense mutations (c.937C>T) in exon 3 and (c.3103C>T) in exon 19 of TRAPPC9 (NM_031466.7) in two unrelated consanguineous families. Conclusion The two novel variants found in TRAPPC9 caused truncated protein and clinical manifestations such as ID, developmental delay, microcephaly, and brain abnormalities in three patients.
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Affiliation(s)
| | - Hossein Mozhdehipanah
- Department of Neurology, Bou Ali Sina Hospital, Qazvin University of Medical Sciences, Qazvin, Iran
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19
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Bodnar B, DeGruttola A, Zhu Y, Lin Y, Zhang Y, Mo X, Hu W. Emerging role of NIK/IKK2-binding protein (NIBP)/trafficking protein particle complex 9 (TRAPPC9) in nervous system diseases. Transl Res 2020; 224:55-70. [PMID: 32434006 PMCID: PMC7442628 DOI: 10.1016/j.trsl.2020.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/02/2020] [Accepted: 05/05/2020] [Indexed: 02/05/2023]
Abstract
NFκB signaling and protein trafficking network play important roles in various biological and pathological processes. NIK-and-IKK2-binding protein (NIBP), also known as trafficking protein particle complex 9 (TRAPPC9), is a prototype member of a novel protein family, and has been shown to regulate both NFκB signaling pathway and protein transport/trafficking. NIBP is extensively expressed in the nervous system and plays an important role in regulating neurogenesis and neuronal differentiation. NIBP/TRAPPC9 mutations have been linked to an autosomal recessive intellectual disability syndrome, called NIBP Syndrome, which is characterized by nonsyndromic autosomal recessive intellectual disability along with other symptoms such as obesity, microcephaly, and facial dysmorphia. As more cases of NIBP Syndrome are identified, new light is being shed on the role of NIBP/TRAPPC9 in the central nervous system developments and diseases. NIBP is also involved in the enteric nervous system. This review will highlight the importance of NIBP/TRAPPC9 in central and enteric nervous system diseases, and the established possible mechanisms for developing a potential therapeutic.
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Affiliation(s)
- Brittany Bodnar
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; MD/PhD and Biomedical Sciences Graduate Program, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Arianna DeGruttola
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; MD/PhD and Biomedical Sciences Graduate Program, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Yuanjun Zhu
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Sciences, Beijing, China
| | - Yuan Lin
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Yonggang Zhang
- Center for Stem Cell Research and Application, Institute of Blood Transfusion, Chinese Academy of Medical Sciences & Peking Union Medical College (CAMS & PUMC), Chengdu, China
| | - Xianming Mo
- Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Wenhui Hu
- Center for Metabolic Disease Research, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; MD/PhD and Biomedical Sciences Graduate Program, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania.
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20
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Wilton KM, Gunderson LB, Hasadsri L, Wood CP, Schimmenti LA. Profound intellectual disability caused by homozygous TRAPPC9 pathogenic variant in a man from Malta. Mol Genet Genomic Med 2020; 8:e1211. [PMID: 32162493 PMCID: PMC7216808 DOI: 10.1002/mgg3.1211] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/24/2020] [Indexed: 01/02/2023] Open
Abstract
Background Intellectual disability is a complex multi‐faceted condition with diverse underlying etiologies. One rare form of intellectual disability is secondary to the loss of TRAPPC9, an activator of NF‐κB and a mediator of intracellular protein processing and trafficking. TRAPPC9 deficiency has been described in 48 patients with more than 15 pathologic variants. Method Clinical evaluation, magnetic resonance imaging, and whole‐exome sequencing were used to characterize the underlying cause of absent speech, restricted/repetitive behaviors, and worsening behavioral outbursts in 27‐year‐old man from Malta. Results Magnetic Resonance Imaging showed morphologic abnormalities, including global cerebral and cerebellar hypoplasia. Genetic analysis through Whole Exome Sequencing identified a homozygous deletion (c.568_574del) in TRAPPC9 resulting in a frameshift, premature stop codon, and ultimately a truncated protein (p.Trp190Argfs*95). In this case, the pathogenic variant was homozygous, identified in both of the parents without known consanguinity. Conclusion Given the phenotype and genotype consistent with a deficiency in TRAPPC9, it is likely that this patient represents a novel case of this rare genetic syndrome. Specifically, this case, in the context of 48 total reported patients, raises questions as to the geographic origin of the pathologic variant and optimal detection and therapeutic intervention for this condition.
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Affiliation(s)
- Katelynn M Wilton
- Mayo Clinic Alix School of Medicine Medical Scientist Training Program, Mayo Clinic, Rochester, MN, USA
| | | | - Linda Hasadsri
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Lisa A Schimmenti
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.,Department of Otorhinolaryngology, Mayo Clinic, Rochester, MN, USA
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21
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Hnoonual A, Graidist P, Kritsaneepaiboon S, Limprasert P. Novel Compound Heterozygous Mutations in the TRAPPC9 Gene in Two Siblings With Autism and Intellectual Disability. Front Genet 2019; 10:61. [PMID: 30853973 PMCID: PMC6396715 DOI: 10.3389/fgene.2019.00061] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/24/2019] [Indexed: 12/11/2022] Open
Abstract
Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with many contributing risk genes and loci. To date, several intellectual disability (ID) susceptibility genes have frequently been identified in ASD. Here, whole exome sequencing was carried out on a proband with ASD and identified compound heterozygous mutations of the TRAPPC9, which plays a role in the neuronal NF-κB signaling pathway. These mutations consisted of a novel frameshift mutation (c.2415_2416insC, p.His806Profs∗9) and a rare splice site mutation (c.3349+1G>A) that were segregated from an unaffected father and unaffected mother, respectively. These two heterozygous mutations were also identified in the patient’s older brother with ID. Quantitative RT-PCR revealed a significant reduction of TRAPPC9 transcript in two siblings. This study first describes compound heterozygous mutations of the TRAPPC9 gene in two siblings with ASD and ID, which is notable as only homozygous mutations or compound heterozygous for copy number variations and rare variant in this gene have been reported to date and associated with autosomal recessive intellectual disability. The two siblings carrying compound heterozygous TRAPPC9 mutations presented with ID, developmental delay, microcephaly and brain abnormalities similarly to the clinical features found in almost cases with homozygous TRAPPC9 mutation in previous studies. Together this study provides evidence that clinical manifestations of TRAPPC9 mutations as seen in our patients with ID and autism may be broader than previous case reports have indicated.
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Affiliation(s)
- Areerat Hnoonual
- Division of Human Genetics, Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand
| | - Potchanapond Graidist
- Department of Biomedical Sciences, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.,The Excellent Research Laboratory of Cancer Molecular Biology, Prince of Songkla University, Songkhla, Thailand
| | - Supika Kritsaneepaiboon
- Department of Radiology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand
| | - Pornprot Limprasert
- Division of Human Genetics, Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.,Faculty of Medicine, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
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22
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Hehir-Kwa JY, Tops BBJ, Kemmeren P. The clinical implementation of copy number detection in the age of next-generation sequencing. Expert Rev Mol Diagn 2018; 18:907-915. [PMID: 30221560 DOI: 10.1080/14737159.2018.1523723] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION The role of copy number variants (CNVs) in disease is now well established. In parallel NGS technologies, such as long-read technologies, there is continual development and data analysis methods continue to be refined. Clinical exome sequencing data is now a reality for many diagnostic laboratories in both congenital genetics and oncology. This provides the ability to detect and report both SNVs and structural variants, including CNVs, using a single assay for a wide range of patient cohorts. Areas covered: Currently, whole-genome sequencing is mainly restricted to research applications and clinical utility studies. Furthermore, detecting the full-size spectrum of CNVs as well as somatic events remains difficult for both exome and whole-genome sequencing. As a result, the full extent of genomic variants in an individual's genome is still largely unknown. Recently, new sequencing technologies have been introduced which maintain the long-range genomic context, aiding the detection of CNVs and structural variants. Expert commentary: The development of long-read sequencing promises to resolve many CNV and SV detection issues but is yet to become established. The current challenge for clinical CNV detection is how to fully exploit all the data which is generated by high throughput sequencing technologies.
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Affiliation(s)
- Jayne Y Hehir-Kwa
- a Princess Máxima Center for Pediatric Oncology , Utrecht , Netherlands
| | - Bastiaan B J Tops
- a Princess Máxima Center for Pediatric Oncology , Utrecht , Netherlands
| | - Patrick Kemmeren
- a Princess Máxima Center for Pediatric Oncology , Utrecht , Netherlands
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Sacher M, Shahrzad N, Kamel H, Milev MP. TRAPPopathies: An emerging set of disorders linked to variations in the genes encoding transport protein particle (TRAPP)-associated proteins. Traffic 2018; 20:5-26. [PMID: 30152084 DOI: 10.1111/tra.12615] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 08/23/2018] [Accepted: 08/26/2018] [Indexed: 02/06/2023]
Abstract
The movement of proteins between cellular compartments requires the orchestrated actions of many factors including Rab family GTPases, Soluble NSF Attachment protein REceptors (SNAREs) and so-called tethering factors. One such tethering factor is called TRAnsport Protein Particle (TRAPP), and in humans, TRAPP proteins are distributed into two related complexes called TRAPP II and III. Although thought to act as a single unit within the complex, in the past few years it has become evident that some TRAPP proteins function independently of the complex. Consistent with this, variations in the genes encoding these proteins result in a spectrum of human diseases with diverse, but partially overlapping, phenotypes. This contrasts with other tethering factors such as COG, where variations in the genes that encode its subunits all result in an identical phenotype. In this review, we present an up-to-date summary of all the known disease-related variations of genes encoding TRAPP-associated proteins and the disorders linked to these variations which we now call TRAPPopathies.
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Affiliation(s)
- Michael Sacher
- Department of Biology, Concordia University, Montreal, Quebec, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Nassim Shahrzad
- Department of Medicine, University of California, San Francisco, California
| | - Hiba Kamel
- Department of Biology, Concordia University, Montreal, Quebec, Canada
| | - Miroslav P Milev
- Department of Biology, Concordia University, Montreal, Quebec, Canada
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