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Kim MJ, Yum MS, Seo GH, Lee Y, Jang HN, Ko TS, Lee BH. Clinical Application of Whole Exome Sequencing to Identify Rare but Remediable Neurologic Disorders. J Clin Med 2020; 9:jcm9113724. [PMID: 33233562 PMCID: PMC7699758 DOI: 10.3390/jcm9113724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022] Open
Abstract
Background: The aim of this study was to describe the application of whole exome sequencing (WES) in the accurate genetic diagnosis and personalized treatment of extremely rare neurogenetic disorders. Methods: From 2017 to 2019, children with neurodevelopmental symptoms were evaluated using WES in the pediatric neurology clinic and medical genetics center. The clinical presentation, laboratory findings including the genetic results from WES, and diagnosis-based treatment and outcomes of the four patients are discussed. Results: A total of 376 children with neurodevelopmental symptom were evaluated by WES, and four patients (1.1%) were diagnosed with treatable neurologic disorders. Patient 1 (Pt 1) showed global muscle hypotonia, dysmorphic facial features, and multiple anomalies beginning in the perinatal period. Pt 1 was diagnosed with congenital myasthenic syndrome 22 of PREPL deficiency. Pt 2 presented with hypotonia and developmental arrest and was diagnosed with autosomal recessive dopa-responsive dystonia due to TH deficiency. Pt 3, who suffered from intractable epilepsy and progressive cognitive decline, was diagnosed with epileptic encephalopathy 47 with a heterozygous FGF12 mutation. Pt 4 presented with motor delay and episodic ataxia and was diagnosed with episodic ataxia type II (heterozygous CACNA1A mutation). The patients’ major neurologic symptoms were remarkably relieved with pyridostigmine (Pt 1), levodopa (Pt 2), sodium channel blocker (Pt 3), and acetazolamide (Pt 4), and most patients regained developmental milestones in the follow-up period (0.4 to 3 years). Conclusions: The early application of WES helps in the identification of extremely rare genetic diseases, for which effective treatment modalities exist. Ultimately, WES resulted in optimal clinical outcomes of affected patients.
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Affiliation(s)
- Min-Jee Kim
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
| | - Mi-Sun Yum
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
- Correspondence: ; Tel.: +82-2-3010-3386; Fax: +82-2-3010-3356
| | - Go Hun Seo
- 3billion Inc., Seoul 06193, Korea; (G.H.S.); (B.H.L.)
| | - Yena Lee
- Department of Genetics, Asan Medical Center, Ulsan University College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea;
| | - Han Na Jang
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
| | - Tae-Sung Ko
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
| | - Beom Hee Lee
- 3billion Inc., Seoul 06193, Korea; (G.H.S.); (B.H.L.)
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Yang Q, Hua R, Qian J, Yi S, Shen F, Zhang Q, Li M, Yi S, Luo J, Fan X. PREPL Deficiency: A Homozygous Splice Site PREPL Mutation in a Patient With Congenital Myasthenic Syndrome and Absence of Ovaries and Hypoplasia of Uterus. Front Genet 2020; 11:198. [PMID: 32218803 PMCID: PMC7078161 DOI: 10.3389/fgene.2020.00198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/20/2020] [Indexed: 11/13/2022] Open
Abstract
Prolyl endopeptidase-like (PREPL) deficiency (MIM 616224) is a very rare congenital disorder characterized by neonatal hypotonia and feeding difficulties, ptosis, neuromuscular symptoms, cognitive impairments, growth hormone deficiency, short stature, and hypergonadotropic hypogonadism. This syndrome is an autosomal recessive disease resulting from mutations in the PREPL gene. Previous reports have associated PREPL deficiency with only one nucleotide substitution, the deletion of four nucleotides, and eight small microdeletions in the PREPL gene In this study, we used whole exome sequencing (WES) to identify a novel homozygous splicing mutation (c.616 + 1G > T) in a 14-year-old Chinese girl with PREPL deficiency. Sequencing of the RT-PCR products from the patient’s blood sample revealed that the c.616 + 1G > T variant disrupted normal splicing in intron 4 leading to an aberrant inclusion of 43 nucleotides in intron, a frameshift, and premature termination codon. Our patient exhibited several of the common phenotypes, including severe neonatal hypotonia, growth impairment and cognitive problems. However, we also observed several unusual phenotypic characteristics: absence of the ovaries, hypoplasia of the uterus, microcephaly and a short neck in patient is alsoobserved. These results provide further evidence for the involvement of PREPL development of the ovaries and uterus. Our findings may provide further insight into the relationship between the genotype and phenotype in collagen-associated diseases and improve the clinical diagnosis of Prolyl endopeptidase-like deficiency.
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Affiliation(s)
- Qi Yang
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Rong Hua
- The Guangxi Zhang Autonomous Region Reproductive Hospital, Nanning, China
| | - Jiale Qian
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Shang Yi
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Fei Shen
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Qiang Zhang
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Mengting Li
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Sheng Yi
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Jingsi Luo
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
| | - Xin Fan
- Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, Nanning, China
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3
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Taroni F, Capone V, Berrettini A, De Marco EA, Manzoni GA, Montini G. A Case of Hypotonia-Cystinuria Syndrome With Genito-Urinary Malformations and Extrarenal Involvement. Front Pediatr 2019; 7:127. [PMID: 31024870 PMCID: PMC6465885 DOI: 10.3389/fped.2019.00127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 03/18/2019] [Indexed: 01/26/2023] Open
Abstract
Hypotonia-Cystinuria syndrome (HCS) is a rare disease, caused by a mutation in two contiguous genes (SLC3A1 and PREPL) localized on chromosome 2p21, and it is characterized by both renal involvement with cystine stones and nervous involvement with hypotonia. We here describe a 2 years old child with HCS associated with other clinical features as congenital anomalies of kidney and urinary tract (primary obstructed megaureter, POM), cryptorchidism and cardiac involvement (patent foramen ovale with atrial septum aneurysm). To the best of our knowledge, cryporchidism and POM have never been reported before in patients with HCS. Moreover, a cardiac involvement has been described only in another case of HCS that, interestingly, presents the same genetic abnormalities as our patient. The diagnosis of HCS can be difficult because neurological signs are aspecific and kidney stones are commonly absent during the first months of life. A better understanding of the complete clinical scenario associated with HCS can help clinicians suspect, diagnose and treat HCS earlier with a positive influence on both neurological and renal outcome.
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Affiliation(s)
- Francesca Taroni
- Pediatric Nephrology, Dialysis and Transplant Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Valentina Capone
- Pediatric Nephrology, Dialysis and Transplant Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Alfredo Berrettini
- Pediatric Urology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Erika Adalgisa De Marco
- Pediatric Urology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Gian Antonio Manzoni
- Pediatric Urology Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Giovanni Montini
- Pediatric Nephrology, Dialysis and Transplant Unit, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy.,Giuliana and Bernardo Caprotti Chair of Pediatrics, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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Kılıç M, Ceylan AC, Örün UA, Kılıç E. First cardiac manifestation of hypotonia-cystinuria syndrome. Metab Brain Dis 2018; 33:1375-1379. [PMID: 29627929 DOI: 10.1007/s11011-018-0226-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/27/2018] [Indexed: 02/03/2023]
Abstract
Hypotonia-cystinuria syndrome is a very rare autosomal recessive contiguous gene deletion syndrome of PREPL and SLC3A1 at 2p21 with neuromuscular and neuroendocrinologic presentation. We report a two-year-six-month-old affected female infant and her five-month-old affected brother with a novel homozygous deletion in SLC3A1 and PREPL gene. Both of siblings had mild facial dysmorphism, hypotonia, feeding problems, failure to thrive, developmental delay. She also had dilated cardiomyopathy which differ from other reported patients. Therefore cardiomyopathy may also be considered one of the features of hypotonia-cystinuria syndrome. With this case report, we present cardiac manifestation of hypotonia-cystinuria syndrome for the first time. Because of two siblings had hyperechogenic bowel in prenatal sonography, it might be a prenatal marker for HCS.
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Affiliation(s)
- Mustafa Kılıç
- Sami Ulus Children Hospital, Metabolism Unit, Babur cad, No: 44, 06080, Altındağ, Ankara, Turkey.
| | - Ahmet Cevdet Ceylan
- Atatürk Training and Research Hospital, Department of Genetics, Yıldırım Beyazıt University, Ankara, Turkey
| | - Utku Arman Örün
- Pediatric Cardiology Unit, Sami Ulus Children Hospital, Ankara, Turkey
| | - Esra Kılıç
- Pediatric Hematology-Oncology Training and Research Hospital, Pediatric Genetic Unit, Ankara, Turkey
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5
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Silva S, Miyake N, Tapia C, Matsumoto N. The second point mutation in PREPL: a case report and literature review. J Hum Genet 2018; 63:677-681. [PMID: 29483676 DOI: 10.1038/s10038-018-0426-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 01/29/2018] [Accepted: 01/31/2018] [Indexed: 12/13/2022]
Abstract
Prolyl endopeptidase-like (PREPL) deficiency (MIM# 616224) is a rare autosomal recessive inherited congenital myasthenic syndrome characterized by neonatal hypotonia, feeding problems, mild dysmorphism, and neuromuscular symptoms, followed by hyperphagia and obesity in later childhood. Some patients also exhibit growth deficits, sexual hormone deficiency, and cognitive impairments. This syndrome is caused by biallelic mutations in PREPL. To date, only one nucleotide deletion and seven small microdeletions in PREPL have been reported. Here we report a female patient with a novel homozygous frameshift mutation in PREPL (NM_006036.4, c.342delA:p.Val115Leufs*39). Her clinical features are similar to those of previously reported cases. The mutation is the first homozygous point mutation reported in humans.
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Affiliation(s)
- Sebastian Silva
- Servicio de Pediatría, Hospital de Puerto Montt, 5507798, Puerto Montt, Chile
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan.
| | - Carolina Tapia
- Instituto de Rehabilitación Teletón, 5502446, Puerto Montt, Chile
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan.
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6
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Panneman DM, Smeitink JA, Rodenburg RJ. Mining for mitochondrial mechanisms: Linking known syndromes to mitochondrial function. Clin Genet 2017; 93:943-951. [PMID: 28686290 DOI: 10.1111/cge.13094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 12/28/2022]
Abstract
Mitochondrial disorders (MDs) are caused by defects in 1 or multiple complexes of the oxidative phosphorylation (OXPHOS) machinery. MDs are associated with a broad range of clinical signs and symptoms, and have considerable clinical overlap with other neuromuscular syndromes. This overlap might be due to involvement of mitochondrial pathways in some of these non-mitochondrial syndromes. Here, we give an overview of around 25 non-mitochondrial syndromes, diagnosed in patients who were initially suspected to have a MD on the basis of clinical and biochemical parameters. In addition, we highlight the mitochondrial connections of 6 of these non-mitochondrial syndromes (eg, Rett syndrome and Dravet syndrome) diagnosed in multiple patients. Further research to unravel the interplay between these genes and mitochondria may help to increase knowledge on these syndromes. Additionally, it may open new avenues for research on pathways interacting with mitochondrial function in order to find new targets for therapeutics to treat MDs. The data presented in this review underline the importance of careful assessment of clinical, genetic, and biochemical data in all patients suspected of a neuromuscular syndrome, and highlights the importance of the role of clinical geneticists, physicians, and clinical biochemists in recognizing the possible mitochondrial connection of non-mitochondrial syndromes.
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Affiliation(s)
- D M Panneman
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - J A Smeitink
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - R J Rodenburg
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
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7
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Régal L, Mårtensson E, Maystadt I, Voermans N, Lederer D, Burlina A, Juan Fita MJ, Hoogeboom AJM, Olsson Engman M, Hollemans T, Schouten M, Meulemans S, Jonson T, François I, Gil Ortega D, Kamsteeg EJ, Creemers JWM. PREPL deficiency: delineation of the phenotype and development of a functional blood assay. Genet Med 2017; 20:109-118. [PMID: 28726805 DOI: 10.1038/gim.2017.74] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 04/17/2017] [Indexed: 12/13/2022] Open
Abstract
PurposePREPL deficiency causes neonatal hypotonia, ptosis, neonatal feeding difficulties, childhood obesity, xerostomia, and growth hormone deficiency. Different recessive contiguous gene deletion syndromes involving PREPL and a variable combination of SLC3A1 (hypotonia-cystinuria syndrome), CAMKMT (atypical hypotonia-cystinuria syndrome), and PPM1B (2p21 deletion syndrome) have been described. In isolated PREPL deficiency, previously described only once, the absence of cystinuria complicates the diagnosis. Therefore, we developed a PREPL blood assay and further delineated the phenotype.MethodsClinical features of new subjects with PREPL deficiency were recorded. The presence of PREPL in lymphocytes and its reactivity with an activity-based probe were evaluated by western blot.ResultsFive subjects with isolated PREPL deficiency, three with hypotonia-cystinuria syndrome, and two with atypical hypotonia-cystinuria syndrome had nine novel alleles. Their IQs ranged from 64 to 112. Adult neuromuscular signs included ptosis, nasal dysarthria, facial weakness, and variable proximal and neck flexor weakness. Autonomic features are prevalent. PREPL protein and reactivity were absent in lymphocytes from subjects with PREPL deficiency, but normal in the clinically similar Prader-Willi syndrome.ConclusionPREPL deficiency causes neuromuscular, autonomic, cognitive, endocrine, and dysmorphic clinical features. PREPL is not deficient in Prader-Willi syndrome. The novel blood test should facilitate the confirmation of PREPL deficiency.
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Affiliation(s)
- Luc Régal
- Laboratory of Biochemical Neuroendocrinology, Department of Human Genetics, University of Leuven, Leuven, Belgium.,Pediatric Neurology and Metabolism, Department of Pediatrics, UZ Brussel, Brussels, Belgium
| | - Emma Mårtensson
- Department of Clinical Genetics, Region Skåne and Lund University, Lund, Sweden
| | - Isabelle Maystadt
- Centre de Génétique Humaine, Institut de Pathologie et Génétique, Charleroi, Belgium
| | - Nicol Voermans
- Department of Neurology, RadboudUMC Nijmegen, Nijmegen, The Netherlands
| | - Damien Lederer
- Centre de Génétique Humaine, Institut de Pathologie et Génétique, Charleroi, Belgium
| | - Alberto Burlina
- Division of Inherited Metabolic Diseases, Department of Pediatrics, University Hospital Padova, Padova, Italy
| | - María Jesús Juan Fita
- Unidad de Metabolopatías, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain
| | - A Jeannette M Hoogeboom
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | | | - Tess Hollemans
- Pediatric Neurology and Metabolism, Department of Pediatrics, UZ Brussel, Brussels, Belgium
| | - Meyke Schouten
- Department of Clinical Genetics, RadboudUMC Nijmegen, Nijmegen, The Netherlands
| | - Sandra Meulemans
- Laboratory of Biochemical Neuroendocrinology, Department of Human Genetics, University of Leuven, Leuven, Belgium
| | - Tord Jonson
- Department of Clinical Genetics, Region Skåne and Lund University, Lund, Sweden
| | - Inge François
- Department of Pediatric Endocrinology, UZ Leuven, Leuven, Belgium
| | - David Gil Ortega
- Unidad de Metabolopatías, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Erik-Jan Kamsteeg
- Department of Clinical Genetics, RadboudUMC Nijmegen, Nijmegen, The Netherlands
| | - John W M Creemers
- Laboratory of Biochemical Neuroendocrinology, Department of Human Genetics, University of Leuven, Leuven, Belgium
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Haziza S, Magnani R, Lan D, Keinan O, Saada A, Hershkovitz E, Yanay N, Cohen Y, Nevo Y, Houtz RL, Sheffield VC, Golan H, Parvari R. Calmodulin Methyltransferase Is Required for Growth, Muscle Strength, Somatosensory Development and Brain Function. PLoS Genet 2015; 11:e1005388. [PMID: 26247364 PMCID: PMC4527749 DOI: 10.1371/journal.pgen.1005388] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/23/2015] [Indexed: 01/11/2023] Open
Abstract
Calmodulin lysine methyl transferase (CaM KMT) is ubiquitously expressed and highly conserved from plants to vertebrates. CaM is frequently trimethylated at Lys-115, however, the role of CaM methylation in vertebrates has not been studied. CaM KMT was found to be homozygously deleted in the 2P21 deletion syndrome that includes 4 genes. These patients present with cystinuria, severe intellectual disabilities, hypotonia, mitochondrial disease and facial dysmorphism. Two siblings with deletion of three of the genes included in the 2P21 deletion syndrome presented with cystinuria, hypotonia, a mild/moderate mental retardation and a respiratory chain complex IV deficiency. To be able to attribute the functional significance of the methylation of CaM in the mouse and the contribution of CaM KMT to the clinical presentation of the 2p21deletion patients, we produced a mouse model lacking only CaM KMT with deletion borders as in the human 2p21deletion syndrome. No compensatory activity for CaM methylation was found. Impairment of complexes I and IV, and less significantly III, of the mitochondrial respiratory chain was more pronounced in the brain than in muscle. CaM KMT is essential for normal body growth and somatosensory development, as well as for the proper functioning of the adult mouse brain. Developmental delay was demonstrated for somatosensory function and for complex behavior, which involved both basal motor function and motivation. The mutant mice also had deficits in motor learning, complex coordination and learning of aversive stimuli. The mouse model contributes to the evaluation of the role of methylated CaM. CaM methylation appears to have a role in growth, muscle strength, somatosensory development and brain function. The current study has clinical implications for human patients. Patients presenting slow growth and muscle weakness that could result from a mitochondrial impairment and mental retardation should be considered for sequence analysis of the CaM KMT gene. Calmodulin (CaM) is a highly abundant, ubiquitous, small protein, which plays a major role in the transmission of calcium signals to target proteins in eukaryotes. Hundreds of CaM targets are known, and their respective cellular functions include signaling, metabolism, cytoskeletal regulation, and ion channel regulation, to name but a few. CaM is frequently modified after translation, including frequently trimethylation at a single amino acid, however, the role of this methylation is not known. Human patients with a homozygous deletion of the gene that methylates CaM, CaM-KMT, are known, but they also have a deletion of additional genes. Thus, to study the role of CaM–KMT, we produced a mouse model in which CaM-KMT is the only deleted gene, with the deletion constructed as in the human patients. The model proved to reveal the function of methylation of CaM, since CaM was found to be non-methylated and the methylation of CaM found to be important in growth, muscle strength, somatosensory development and brain function. The current study also has clinical implications for human patients. Patients presenting slow growth and muscle weakness that could result from a mitochondrial impairment and mental retardation should be considered for sequence analysis of the CaM KMT gene.
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Affiliation(s)
- Sitvanit Haziza
- Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Roberta Magnani
- Department of Horticulture, University of Kentucky, Lexington, Kentucky, United States of America
| | - Dima Lan
- Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Omer Keinan
- Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Ann Saada
- Department of Genetic and Metabolic Diseases, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Eli Hershkovitz
- Pediatric Endocrinology & Metabolism Unit, Soroka Medical Center, Beer Sheva, Israel
| | - Nurit Yanay
- Pediatric Neuromuscular Laboratory and Pediatric Neurology Unit Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Yoram Cohen
- Pesticides and Mycotoxins Division, Aminolab, Weizmann Science Park, Ness Ziona, Israel
| | - Yoram Nevo
- Pediatric Neuromuscular Laboratory and Pediatric Neurology Unit Hadassah, Hebrew University Medical Center, Jerusalem, Israel
- Institute of Neurology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
| | - Robert L. Houtz
- Department of Horticulture, University of Kentucky, Lexington, Kentucky, United States of America
| | - Val C. Sheffield
- Department of Pediatrics, Division of Medical Genetics and Hughes Medical Institute, University of Iowa, Iowa City, Iowa, United States of America
| | - Hava Golan
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ruti Parvari
- Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- National Institute of Biotechnology in the Negev, Ben Gurion University of the Negev, Beer Sheva, Israel
- * E-mail:
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9
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Régal L, Shen XM, Selcen D, Verhille C, Meulemans S, Creemers JWM, Engel AG. PREPL deficiency with or without cystinuria causes a novel myasthenic syndrome. Neurology 2014; 82:1254-60. [PMID: 24610330 PMCID: PMC4001208 DOI: 10.1212/wnl.0000000000000295] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/26/2013] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE To investigate the genetic and physiologic basis of the neuromuscular symptoms of hypotonia-cystinuria syndrome (HCS) and isolated PREPL deficiency, and their response to therapy. METHODS We performed molecular genetic, histochemical, immunoblot, and ultrastructural studies, investigated neuromuscular transmission in vitro in a patient with isolated PREPL deficiency, and evaluated the effect of pyridostigmine in this patient and in 3 patients with the HCS. RESULTS HCS is caused by recessive deletions involving the SLC3A1 and PREPL genes. The major clinical features of HCS are type A cystinuria, growth hormone deficiency, muscle weakness, ptosis, and feeding problems. The proband with isolated PREPL deficiency had myasthenic symptoms since birth and a positive edrophonium test but no cystinuria. She and 1 of 3 patients with HCS responded transiently to pyridostigmine during infancy. The proband harbors a paternally inherited nonsense mutation in PREPL and a maternally inherited deletion involving both PREPL and SLC3A1; therefore, the PREPL deficiency determines the phenotype. We detected no PREPL expression in the patient's muscle and endplates. Electrophysiology studies revealed decreased quantal content of the endplate potential and reduced amplitude of the miniature endplate potential without endplate acetylcholine receptor deficiency or altered endplate geometry. CONCLUSION Isolated PREPL deficiency is a novel monogenic disorder that causes a congenital myasthenic syndrome with pre- and postsynaptic features and growth hormone deficiency. The myasthenic symptoms in PREPL deficiency with or without cystinuria may respond to pyridostigmine in early life. We attribute the myasthenia to abrogated interaction of PREPL with adaptor protein 1.
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Affiliation(s)
- Luc Régal
- From the Center of Human Genetics (L.R., J.W.M.C., S.M.), Laboratory of Biochemical Neuroendocrinology, KU Leuven; Department of Pediatrics and Pediatric Metabolic Disorders (C.V.), University Hospital Leuven, Belgium; and Department of Neurology (X.-M.S., D.S., A.G.E.), Mayo Clinic, Rochester, MN
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10
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Lone AM, Leidl M, McFedries AK, Horner JW, Creemers J, Saghatelian A. Deletion of PREPl causes growth impairment and hypotonia in mice. PLoS One 2014; 9:e89160. [PMID: 24586561 PMCID: PMC3938459 DOI: 10.1371/journal.pone.0089160] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 01/03/2014] [Indexed: 01/22/2023] Open
Abstract
Genetic studies of rare diseases can identify genes of unknown function that strongly impact human physiology. Prolyl endopeptidase-like (PREPL) is an uncharacterized member of the prolyl peptidase family that was discovered because of its deletion in humans with hypotonia-cystinuria syndrome (HCS). HCS is characterized by a number of physiological changes including diminished growth and neonatal hypotonia or low muscle tone. HCS patients have deletions in other genes as well, making it difficult to tease apart the specific role of PREPL. Here, we develop a PREPL null (PREPL(-/-)) mouse model to address the physiological role of this enzyme. Deletion of exon 11 from the Prepl gene, which encodes key catalytic amino acids, leads to a loss of PREPL protein as well as lower Prepl mRNA levels. PREPL(-/-) mice have a pronounced growth phenotype, being significantly shorter and lighter than their wild type (PREPL(+/+)) counterparts. A righting assay revealed that PREPL(-/-) pups took significantly longer than PREPL(+/+) pups to right themselves when placed on their backs. This deficit indicates that PREPL(-/-) mice suffer from neonatal hypotonia. According to these results, PREPL regulates growth and neonatal hypotonia in mice, which supports the idea that PREPL causes diminished growth and neonatal hypotonia in humans with HCS. These animals provide a valuable asset in deciphering the underlying biochemical, cellular and physiological pathways that link PREPL to HCS, and this may eventually lead to new insights in the treatment of this disease.
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Affiliation(s)
- Anna Mari Lone
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Mathias Leidl
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Amanda K. McFedries
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - James W. Horner
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Institute for Applied Cancer Science, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - John Creemers
- Laboratory for Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Alan Saghatelian
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
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Bartholdi D, Asadollahi R, Oneda B, Schmitt-Mechelke T, Tonella P, Baumer A, Rauch A. Further delineation of genotype-phenotype correlation in homozygous 2p21 deletion syndromes: first description of patients without cystinuria. Am J Med Genet A 2013; 161A:1853-9. [PMID: 23794250 DOI: 10.1002/ajmg.a.35994] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 03/28/2013] [Indexed: 02/04/2023]
Abstract
Homozygous contiguous gene deletion syndromes are rare. On 2p21, however, several overlapping homozygous gene deletion syndromes have been described, all presenting with cystinuria but otherwise distinct phenotypes. Hypotonia-cystinuria syndrome (HCS, OMIM606407) is characterized by infantile hypotonia, poor feeding, and growth hormone deficiency. Affected individuals carry homozygous deletions including the cystinuria gene SLC3A1 and the adjacent PREPL gene. Larger homozygous deletions in this region encompassing the PPM1B, SLC3A1, PREPL, and C2orf34 (CAMKMT) genes result in a more severe phenotype, the 2p21 deletion syndrome. A phenotype intermediate to HCS and the 2p21 deletion syndrome is termed atypical HCS and is caused by deletion of SLC3A1, PREPL, and C2orf34 (CAMKMT). Using high resolution SNP array molecular karyotyping we identified two siblings with a homozygous deletion of 83 kb partially encompassing the genes PREPL and C2orf34 (CAMKMT), but not the SLC3A1 gene. The affected siblings display a recognizable phenotype which is similar to atypical HCS with regard to growth failure and neuro-muscular features, but is characterized by lack of cystinuria. The patients also exhibit features which have not been reported to date such as cleft palate and genital abnormalities. In conclusion, we report the first patients with a homozygous 2p21 deletion syndrome without cystinuria and further delineate the complex genotype-phenotype correlations of homozygous microdeletion syndromes of this region.
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Affiliation(s)
- Deborah Bartholdi
- Institute of Medical Genetics, University of Zurich, Schwerzenbach, Switzerland.
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12
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Morawski M, Nuytens K, Juhasz T, Zeitschel U, Seeger G, Waelkens E, Regal L, Schulz I, Arendt T, Szeltner Z, Creemers J, Rossner S. Cellular and ultra structural evidence for cytoskeletal localization of prolyl endopeptidase-like protein in neurons. Neuroscience 2013; 242:128-39. [PMID: 23485813 DOI: 10.1016/j.neuroscience.2013.02.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/13/2013] [Accepted: 02/14/2013] [Indexed: 12/11/2022]
Abstract
The biochemical properties and subcellular localization of prolyl endopeptidase (PREP) in brain are well characterized and its implications in the realization of cognitive processes and in the pathogenesis of neurodegenerative disorders are a matter of intensive investigation. In contrast, very little is known about its homolog, the PREP-like protein (PREPL). In order to obtain initial hints about the involvement of PREPL in physiological processes, a differential proteomic screen was performed with human skin fibroblasts from controls and patients with PREPL deficiency (hypotonia-cystinuria syndrome). The majority of affected proteins represented cytoskeletal proteins, including caldesmon, tropomyosin α3 chain, lamin A, β-actin, γ-actin, vimentin and zyxin. Therefore, the analysis of PREPL subcellular localization by confocal laser scanning and electron microscopy in mouse neurons was focused on the cytoskeleton. The co-localization of PREPL with cytoskeletal marker proteins such as β-actin and microtubulin-associated protein-2 was observed, in addition to the presence of PREPL within Golgi apparatus and growth cones. In the mouse brain, PREPL is neuronally expressed and highly abundant in neocortex, substantia nigra and locus coeruleus. This mirrors to some extent the distribution pattern of PREP and points toward redundant functions of both proteins. In the human neocortex, PREPL immunostaining was found in the cytoplasm and in neuropil, in particular of layer V pyramidal neurons. This staining was reduced in the neocortex of Alzheimer's disease (AD) patients. Moreover, in AD brains, PREPL immunoreactivity was observed in the nucleus and in varicose neuritic processes. Our data indicate physiological functions of PREPL associated with the cytoskeleton, which may be affected under conditions of cytoskeletal degeneration.
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Affiliation(s)
- M Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04109 Leipzig, Jahnallee 59, Germany
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