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Fortier M, Cauhapé M, Buono S, Becker J, Menuet A, Branchu J, Ricca I, Mero S, Dorgham K, El Hachimi KH, Dobrenis K, Colsch B, Samaroo D, Devaux M, Durr A, Stevanin G, Santorelli FM, Colombo S, Cowling B, Darios F. Decreasing ganglioside synthesis delays motor and cognitive symptom onset in Spg11 knockout mice. Neurobiol Dis 2024; 199:106564. [PMID: 38876323 DOI: 10.1016/j.nbd.2024.106564] [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: 01/30/2024] [Revised: 06/11/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024] Open
Abstract
Biallelic variants in the SPG11 gene account for the most common form of autosomal recessive hereditary spastic paraplegia characterized by motor and cognitive impairment, with currently no therapeutic option. We previously observed in a Spg11 knockout mouse that neurodegeneration is associated with accumulation of gangliosides in lysosomes. To test whether a substrate reduction therapy could be a therapeutic option, we downregulated the key enzyme involved in ganglioside biosynthesis using an AAV-PHP.eB viral vector expressing a miRNA targeting St3gal5. Downregulation of St3gal5 in Spg11 knockout mice prevented the accumulation of gangliosides, delayed the onset of motor and cognitive symptoms, and prevented the upregulation of serum levels of neurofilament light chain, a biomarker widely used in neurodegenerative diseases. Importantly, similar results were observed when Spg11 knockout mice were administrated venglustat, a pharmacological inhibitor of glucosylceramide synthase expected to decrease ganglioside synthesis. Downregulation of St3gal5 or venglustat administration in Spg11 knockout mice strongly decreased the formation of axonal spheroids, previously associated with impaired trafficking. Venglustat had similar effect on cultured human SPG11 neurons. In conclusion, this work identifies the first disease-modifying therapeutic strategy in SPG11, and provides data supporting its relevance for therapeutic testing in SPG11 patients.
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Affiliation(s)
- Manon Fortier
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Margaux Cauhapé
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Suzie Buono
- Dynacure SA (now Flamingo Therapeutics NV), Illkirch, France
| | - Julien Becker
- Dynacure SA (now Flamingo Therapeutics NV), Illkirch, France
| | - Alexia Menuet
- Dynacure SA (now Flamingo Therapeutics NV), Illkirch, France
| | - Julien Branchu
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Ivana Ricca
- Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy
| | - Serena Mero
- Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy
| | - Karim Dorgham
- Sorbonne Université, INSERM, Centre d'Immunologie et des Maladies Infectieuses-Paris (CIMI-Paris), Paris, France
| | - Khalid-Hamid El Hachimi
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France; EPHE, PSL Research University, Paris, France
| | - Kostantin Dobrenis
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Benoit Colsch
- Université Paris-Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé, MetaboHUB, Gif sur Yvette, France
| | - Dominic Samaroo
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Morgan Devaux
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Alexandra Durr
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Giovanni Stevanin
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France; EPHE, PSL Research University, Paris, France; University of Bordeaux, CNRS, INCIA, UMR 5287, NRGen Team, Bordeaux, France
| | | | - Sophie Colombo
- Dynacure SA (now Flamingo Therapeutics NV), Illkirch, France
| | - Belinda Cowling
- Dynacure SA (now Flamingo Therapeutics NV), Illkirch, France
| | - Frédéric Darios
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM U1127, CNRS UMR 7225, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
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Brankovic M, Ivanovic V, Basta I, Khang R, Lee E, Stevic Z, Ralic B, Tubic R, Seo G, Markovic V, Bozovic I, Svetel M, Marjanovic A, Veselinovic N, Mesaros S, Jankovic M, Savic-Pavicevic D, Jovin Z, Novakovic I, Lee H, Peric S. Whole exome sequencing in Serbian patients with hereditary spastic paraplegia. Neurogenetics 2024:10.1007/s10048-024-00755-x. [PMID: 38499745 DOI: 10.1007/s10048-024-00755-x] [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: 12/14/2023] [Accepted: 03/08/2024] [Indexed: 03/20/2024]
Abstract
Hereditary spastic paraplegia (HSP) is a group of neurodegenerative diseases with a high genetic and clinical heterogeneity. Numerous HSP patients remain genetically undiagnosed despite screening for known genetic causes of HSP. Therefore, identification of novel variants and genes is needed. Our previous study analyzed 74 adult Serbian HSP patients from 65 families using panel of the 13 most common HSP genes in combination with a copy number variation analysis. Conclusive genetic findings were established in 23 patients from 19 families (29%). In the present study, nine patients from nine families previously negative on the HSP gene panel were selected for the whole exome sequencing (WES). Further, 44 newly diagnosed adult HSP patients from 44 families were sent to WES directly, since many studies showed WES may be used as the first step in HSP diagnosis. WES analysis of cohort 1 revealed a likely genetic cause in five (56%) of nine HSP families, including variants in the ETHE1, ZFYVE26, RNF170, CAPN1, and WASHC5 genes. In cohort 2, possible causative variants were found in seven (16%) of 44 patients (later updated to 27% when other diagnosis were excluded), comprising six different genes: SPAST, SPG11, WASCH5, KIF1A, KIF5A, and ABCD1. These results expand the genetic spectrum of HSP patients in Serbia and the region with implications for molecular genetic diagnosis and future causative therapies. Wide HSP panel can be the first step in diagnosis, alongside with the copy number variation (CNV) analysis, while WES should be performed after.
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Affiliation(s)
- Marija Brankovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia.
| | - Vukan Ivanovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
| | - Ivana Basta
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | | | | | - Zorica Stevic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | | | - Radoje Tubic
- Institute for Oncology and Radiology of Serbia, Belgrade, Serbia
| | | | - Vladana Markovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Ivo Bozovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
| | - Marina Svetel
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Ana Marjanovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
| | - Nikola Veselinovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Sarlota Mesaros
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Milena Jankovic
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Dusanka Savic-Pavicevic
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Zita Jovin
- Neurology Clinic, University Clinical Center of Vojvodina, Novi Sad, Serbia
| | - Ivana Novakovic
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
| | - Hane Lee
- 3Billion, Inc., Seoul, South Korea
| | - Stojan Peric
- Faculty of Medicine, University of Belgrade, Dr Subotica 6, Belgrade, Serbia
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
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Malina J, Huessler EM, Jöckel KH, Boog-Whiteside E, Jeschonneck N, Schröder B, Schüle R, Kühl T, Klebe S. Development and validation of TreatHSP-QoL: a patient-reported outcome measure for health-related quality of life in hereditary spastic paraplegia. Orphanet J Rare Dis 2024; 19:2. [PMID: 38167479 PMCID: PMC10763482 DOI: 10.1186/s13023-023-03012-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Hereditary spastic paraplegia (HSP) is a rare neurodegenerative disease that lacks specific and validated patient-centered outcome measures (PCOMs). We aimed to develop and validate a health-related quality of life (HRQoL) questionnaire specific to HSP ("TreatHSP-QoL") that could be used as a PCOM. RESULTS The pilot-items of the TreatHSP-QoL (45 five-level Likert scale items, with values per item between 0 and 4) were developed based on a qualitative data analysis of 54 semi-structured interviews, conducted in person with 36 HSP patients and 18 caregivers. It was then reduced and modified through the validation process to 25 items. The main validation was performed using the online questionnaire in 242 HSP patients and 56 caregivers. The exploratory factor analysis defined five subdomains. Cronbach's alpha ranged from 0.57 to 0.85 for the subdomains and reached 0.85 for the total score. The test-retest Pearson correlation reached 0.86 (95% Confidence Interval (CI) [0.79, 0.91]). Pearson correlations with the EuroQol-5 Dimension (5 levels) (EQ-5D-5L) and Friedreich Ataxia Rating Scale-Activities of Daily Living (FARS-ADL) questionnaires varied strongly among the subdomains, with the total scores reaching 0.53 (95% CI [0.42, 0.61]) and -0.45 (95% CI [- 0.55, - 0.35]), respectively. The caregiver-patient response Pearson correlation ranged between 0.64 and 0.82 for subdomains and reached 0.65 (95% CI [0.38, 0.81]) for the total score. CONCLUSIONS TreatHSP-QoL can be used in high-quality clinical trials and clinical practice as a disease-specific PCOM (i.e., HRQoL measure) and is also applicable as a proxy questionnaire. Score values between 0 and 100 can be reached, where higher value represents better HRQoL. The Pearson correlations to the EQ-5D-5L and FARS-ADL support the additional value and need of HSP-specific PCOM, while non-specific QoL-assessment and specific clinical self-assessment tools already exist. All in all, the results demonstrate good validity and reliability for this new patient-centered questionnaire for HSP.
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Affiliation(s)
| | - Eva-Maria Huessler
- Institute for Medical Informatics, Biometry and Epidemiology, University Hospital Essen, Essen, Germany
| | - Karl-Heinz Jöckel
- Institute for Medical Informatics, Biometry and Epidemiology, University Hospital Essen, Essen, Germany
| | | | | | | | - Rebecca Schüle
- Division of Neurodegenerative Diseases, Department of Neurology, Heidelberg University Hospital and Faculty of Medicine, Heidelberg, Germany
- Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Tobias Kühl
- Center for Clinical Trials, University Hospital Essen, Essen, Germany
| | - Stephan Klebe
- Department of Neurology, University Hospital Essen, Essen, Germany.
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Chen X, Li X, Tan Y, Yang D, Lu L, Deng Y, Xu R. Identification of c.1495C > T mutation in SPAST gene in a family of Han Chinese with hereditary spastic paraplegia. Neurosci Lett 2023; 812:137399. [PMID: 37473796 DOI: 10.1016/j.neulet.2023.137399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023]
Abstract
BACKGROUND Hereditary spastic paraplegia 4 (SPG4) caused by spastin (SPAST) gene mutations accounts for 40-45% of hereditary spastic paraplegia (HSP) cases. To search for more genetic evidences for the pathogenesis of HSP, the SPAST genotype and clinical phenotype of a Chinese Han SPG4 family were analysed in this study. METHODS The clinical data of the proband and his family members were collected. Whole genomic DNA was extracted from peripheral blood, and the gene detection and pathogenicity analysis of mutations were conducted using whole-exome sequencing technology. Suspected pathogenic mutations were identified. Verification within this family was conducted by Sanger sequencing. RESULTS Eight (4 males and 4 females) of 20 members in 4 generations had SPG4. All patients presented with the high feet arches (pes cavus), the abnormal gait, the active tendon reflexes of the upper limbs, the hyperreflexia of the lower limbs, and the positive ankle clonus and Babinski's signs bilaterally. In the proband, we found a heterozygous mutation c.1495C > T in SPAST gene, which was associated with the autosomal dominant SPG4. Both the daughters and granddaughters of the proband in this family were verified to carry this mutation. The clinical characteristics of the SPG4 patients in this family are in line with the simple type of HSP. Heterozygous c.1495C > T is a pathogenic mutation in this family. CONCLUSION In this study, we identified a c.1495C > T mutation in the SPAST gene in a Han Chinese family, enriching the mutation spectrum of SPG4.
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Affiliation(s)
- Xiaohong Chen
- Department of Neurology, The First Hospital of Nanchang, Nanchang 330006, Jiangxi, China
| | - Xinming Li
- Department of Neurology, The First Hospital of Nanchang, Nanchang 330006, Jiangxi, China
| | - Yu Tan
- Department of Neurology, The First Hospital of Nanchang, Nanchang 330006, Jiangxi, China
| | - Dejiang Yang
- Department of Neurology, The First Hospital of Nanchang, Nanchang 330006, Jiangxi, China
| | - Lijun Lu
- Department of Neurology, The First Hospital of Nanchang, Nanchang 330006, Jiangxi, China
| | - Youqing Deng
- Department of Neurology, The First Hospital of Nanchang, Nanchang 330006, Jiangxi, China.
| | - Renshi Xu
- Department of Neurology, Jiangxi Provincial People's Hospital, The Clinical College of Nanchang College, The First Affiliated Hospital of Nanchang College, Nanchang 330006, Jiangxi, China.
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Fang SY, Chou YT, Hsu KC, Hsu SL, Yu KW, Tsai YS, Liao YC, Tsai PC, Lee YC. Clinical and genetic characterization of NIPA1 mutations in a Taiwanese cohort with hereditary spastic paraplegia. Ann Clin Transl Neurol 2023; 10:353-362. [PMID: 36607129 PMCID: PMC10014004 DOI: 10.1002/acn3.51724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/10/2022] [Accepted: 12/17/2022] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE NIPA1 mutations have been implicated in hereditary spastic paraplegia (HSP) as the cause of spastic paraplegia type 6 (SPG6). The aim of this study was to investigate the clinical and genetic features of SPG6 in a Taiwanese HSP cohort. METHODS We screened 242 unrelated Taiwanese patients with HSP for NIPA1 mutations. The clinical features of patients with a NIPA1 mutation were analyzed. Minigene-based splicing assay, RT-PCR analysis on the patients' RNA, and cell-based protein expression study were utilized to assess the effects of the mutations on splicing and protein expression. RESULTS Two patients were identified to carry a different heterozygous NIPA1 mutation. The two mutations, c.316G>A and c.316G>C, are located in the 3' end of NIPA1 exon 3 near the exon-intron boundary and putatively lead to the same amino acid substitution, p.G106R. The patient harboring NIPA1 c.316G>A manifested spastic paraplegia, epilepsy and schizophrenia since age 17 years, whereas the individual carrying NIPA1 c.316G>C had pure HSP since age 12 years. We reviewed literature and found that epilepsy was present in multiple individuals with NIPA1 c.316G>A but none with NIPA1 c.316G>C. Functional studies demonstrated that both mutations did not affect splicing, but only the c.316G>A mutation was associated with a significantly reduced NIPA1 protein expression. INTERPRETATION SPG6 accounted for 0.8% of HSP cases in the Taiwanese cohort. The NIPA1 c.316G>A and c.316G>C mutations are associated with adolescent-onset complex and pure form HSP, respectively. The different effects on protein expression of the two mutations may be associated with their phenotypic discrepancy.
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Affiliation(s)
- Shih-Yu Fang
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Neurology, National Yang Ming Chiao Tung University School of Medicine, Taipei, Taiwan
| | - Ying-Tsen Chou
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Kuo-Chou Hsu
- Department of Medicine, Taipei Veterans General Hospital Yuanshan Branch, Yuanshan, Taiwan
| | - Shao-Lun Hsu
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Neurology, National Yang Ming Chiao Tung University School of Medicine, Taipei, Taiwan
| | - Kai-Wei Yu
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yu-Shuen Tsai
- Center for Systems and Synthetic Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Chu Liao
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Neurology, National Yang Ming Chiao Tung University School of Medicine, Taipei, Taiwan.,Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Pei-Chien Tsai
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Chung Lee
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Neurology, National Yang Ming Chiao Tung University School of Medicine, Taipei, Taiwan.,Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Hereditary spastic paraplegia SPG13 mutation increases structural stability and ATPase activity of human mitochondrial chaperonin. Sci Rep 2022; 12:18321. [PMID: 36316435 PMCID: PMC9622745 DOI: 10.1038/s41598-022-21993-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/07/2022] [Indexed: 12/31/2022] Open
Abstract
Human mitochondrial chaperonin mHsp60 is broadly associated with various human health conditions and the V72I mutation in mHsp60 causes a form of hereditary spastic paraplegia, a neurodegenerative disease. The main function of mHsp60 is to assist folding of mitochondrial proteins in an ATP-dependent manner. In this study, we unexpectedly found that mutant mHsp60V72I was more stable structurally and more active in the ATPase activity than the wildtype. Analysis of our recently solved cryo-EM structure of mHsp60 revealed allosteric roles of V72I in structural stability and ATPase activity, which were supported by studies including those using the V72A mutation. Despite with the increases in structural stability and ATPase activity, mHsp60V72I was less efficient in folding malate dehydrogenase, a putative mHsp60 substrate protein in mitochondria and also commonly used in chaperonin studies. In addition, although mHsp60V72I along with its cochaperonin mHsp10 was able to substitute the E. coli chaperonin system in supporting cell growth under normal temperature of 37 °C, it was unable under heat shock temperature of 42 °C. Our results support the importance of structural dynamics and an optimal ATP turnover that mHsp60 has evolved for its function and physiology. We propose that unproductive energy utilization, or hyperactive ATPase activity and compromised folding function, not mutually exclusive, are responsible for the V72I pathology in neurodegenerative disease.
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Husain M. New mechanistic insights into hereditary spastic paraplegias. Brain 2022; 145:2937-2938. [PMID: 36103409 DOI: 10.1093/brain/awac288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Phenotypic and Genetic Heterogeneity of Adult Patients with Hereditary Spastic Paraplegia from Serbia. Cells 2022; 11:cells11182804. [PMID: 36139378 PMCID: PMC9497238 DOI: 10.3390/cells11182804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/02/2022] [Accepted: 09/03/2022] [Indexed: 11/17/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) is among the most genetically diverse of all monogenic diseases. The aim was to analyze the genetic causes of HSP among adult Serbian patients. The study comprised 74 patients from 65 families clinically diagnosed with HSP during a nine-year prospective period. A panel of thirteen genes was analyzed: L1CAM (SPG1), PLP1 (SPG2), ATL1 (SPG3A), SPAST (SPG4), CYP7B1 (SPG5A), SPG7 (SPG7), KIF5A (SPG10), SPG11 (SPG11), ZYFVE26 (SPG15), REEP1 (SPG31), ATP13A2 (SPG78), DYNC1H1, and BICD2 using a next generation sequencing-based technique. A copy number variation (CNV) test for SPAST, SPG7, and SPG11 was also performed. Twenty-three patients from 19 families (29.2%) had conclusive genetic findings, including 75.0% of families with autosomal dominant and 25.0% with autosomal recessive inheritance, and 15.7% of sporadic cases. Twelve families had mutations in the SPAST gene, usually with a pure HSP phenotype. Three sporadic patients had conclusive findings in the SPG11 gene. Two unrelated patients carried a homozygous pathogenic mutation c.233T>A (p.L78*) in SPG7 that is a founder Roma mutation. One patient had a heterozygous de novo variant in the KIF5A gene, and one had a compound heterozygous mutation in the ZYFVE26 gene. The combined genetic yield of our gene panel and CNV analysis for HSP was around 30%. Our findings broaden the knowledge on the genetic epidemiology of HSP, with implications for molecular diagnostics in this region.
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