1
|
Khani M, Nafissi S, Shamshiri H, Moazzeni H, Taheri H, Sadeghi M, Salehi N, Chitsazian F, Elahi E. Identification of UBA1 as the causative gene of an X-linked non-Kennedy SBMA. Eur J Neurol 2022; 29:3556-3563. [PMID: 35996994 DOI: 10.1111/ene.15528] [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: 07/26/2022] [Accepted: 08/18/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Spinal-bulbar muscular atrophy (SBMA; Kennedy's Disease) is a motor neuron disease (MND). Kennedy's Disease is nearly exclusively caused by mutations in the androgen receptor encoding gene (AR). We report results of studies aimed at identification of the genetic cause of a disease that best approximates SBMA in a pedigree (four patients) without mutations in AR. METHODS Clinical investigations included thorough neurologic and non-neurologic examinations and testings. Genetic analysis was performed by exome sequencing using standard protocols. UBA1 mutations were modeled on the crystal structure of UBA1. RESULTS The clinical features of the patients are described in detail. A missense mutation in UBA1 (c.T1499C; p.Ile500Thr) was identified as the probable cause of the non-Kennedy SBMA in the pedigree. Like AR, UBA1 is positioned on Chromosome X. UBA1 is a highly conserved gene. It encodes ubiquitin like modifier activating enzyme 1 (UBA1) which is the major E1 enzyme of the ubiquitin-proteasome system. Interestingly, UBA1 mutations can also cause infantile-onset X-linked spinal muscular atrophy (XL-SMA). The mutation identified here and the XL-SMA causative mutations were shown to affect amino acids positioned in the vicinity of UBA1's ATP binding site and to cause structural changes. CONCLUSION UBA1 was identified as a novel SBMA causative gene. The gene affects protein homeostasis which is one of most important components of the pathology of neurodegeneration. The contribution of this same gene to the etiology of XL-SMA is discussed.
Collapse
Affiliation(s)
- Marzieh Khani
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Shahriar Nafissi
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hosein Shamshiri
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Moazzeni
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hanieh Taheri
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Mehdi Sadeghi
- National Institute for Genetic Engineering and Biotechnology, Tehran, Iran
| | - Najmeh Salehi
- School of Biological Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| | | | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| |
Collapse
|
2
|
Genetic disorders of cellular trafficking. Trends Genet 2022; 38:724-751. [DOI: 10.1016/j.tig.2022.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 02/11/2022] [Accepted: 02/28/2022] [Indexed: 02/06/2023]
|
3
|
Khorrami M, Tabatabaiefar MA, Khorram E, Yaghini O, Rezaei M, Hejazifar A, Riahinezhad M, Kheirollahi M. Homozygous TFG gene variants expanding the mutational and clinical spectrum of hereditary spastic paraplegia 57 and a review of literature. J Hum Genet 2021; 66:973-981. [PMID: 33767317 DOI: 10.1038/s10038-021-00919-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/20/2021] [Accepted: 03/04/2021] [Indexed: 01/17/2023]
Abstract
In recent years, the tropomyosin-receptor kinase fused gene (TFG) has been linked to diverse hereditary neurodegenerative disorders, including a very rare complex hereditary spastic paraplegia, named spastic paraplegia type 57 (SPG57). Until now, four pathogenic homozygous variants of the TFG gene have been reported associated with SPG57. Two consanguineous Iranian families (1 and 2), the first one with two affected members and the second one with one, all with an early-onset progressive muscle weakness, spasticity, and several neurological symptoms were examined via the whole-exome sequencing. Two homozygous missense variants including c.41A>G (p.Lys14Arg) and c.316C>T (p.Arg106Cys) have been found in the related families. The candidate variants were confirmed by Sanger sequencing and found to co-segregate with the disease in families. The bioinformatics analysis showed the deleterious effects of these nucleotide changes and the variants were classified as pathogenic according to ACMG guidelines. A comparison of the clinical presentation of the patients harboring c.41A>G (p.Lys14Arg) with previously reported SPG57 revealed variability in the severity state and unreported clinical presentation, including, facial atrophy, nystagmus, hyperelastic skin, cryptorchidism, hirsutism, kyphoscoliosis, and pectus excavatum. The affected member of the second family carried a previously reported homozygous c.316C>T (p.Arg106Cys) variant and displayed a complex HSP including optic atrophy. Remarkable clinical differences were observed between the family 1 and 2 harboring the c.41A>G (p.Lys14Arg) and c.316C>T (p.Arg106Cys) variants, which could be attributed to the distinct affected domains (PB1 domains and coiled-coil domains), and therefore, SPG57 might have been representing phenotype vs. variant position correlation.
Collapse
Affiliation(s)
- Mehdi Khorrami
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Erfan Khorram
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Omid Yaghini
- Department of Pediatrics, School of Medicine, Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mojgan Rezaei
- Department of Biology, Faculty of Science, Yazd University, Yazd, Iran
| | - Arash Hejazifar
- Department of Biology, School of Sciences, The University of Isfahan, Isfahan, Iran
| | - Maryam Riahinezhad
- Department of Radiology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Majid Kheirollahi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
| |
Collapse
|
4
|
Khani M, Taheri H, Shamshiri H, Moazzeni H, Hardy J, Bras JT, InanlooRahatloo K, Alavi A, Nafissi S, Elahi E. Deep geno- and phenotyping in two consanguineous families with CMT2 reveals HADHA as an unusual disease-causing gene and an intronic variant in GDAP1 as an unusual mutation. J Neurol 2020; 268:640-650. [PMID: 32897397 DOI: 10.1007/s00415-020-10171-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) disease is a prevalent and heterogeneous peripheral neuropathy. Most patients affected with the axonal form of CMT (CMT2) do not harbor mutations in the approximately 90 known CMT-associated genes. We aimed to identify causative genes in two CMT2 pedigrees. METHODS Neurologic examination, laboratory tests and brain MRIs were performed. Genetic analysis included exome sequencing of four patients from the two pedigrees. The predicted effect of a deep intronic mutation on splicing was tested by regular and real-time PCR and sequencing. RESULTS Clinical data were consistent with CMT2 diagnosis. Inheritance patterns were autosomal recessive. Exome data of CMT2-101 did not include mutations in known CMT-associated genes. Sequence data, segregation analysis, bioinformatics analysis, evolutionary conservation, and information in the literature strongly implicated HADHA as the causative gene. An intronic variation positioned 23 nucleotides away from following intron/exon border in GDAP1 was ultimately identified as cause of CMT in CMT2-102. It was shown to affect splicing. CONCLUSION The finding of a HADHA mutation as a cause of CMT is of interest because its encoded protein is a subunit of the mitochondrial trifunctional protein (MTP) complex, a mitochondrial enzyme involved in long chain fatty acid oxidation. Long chain fatty acid oxidation is an important source of energy for skeletal muscles. The mutation found in CMT2-102 is only the second intronic mutation reported in GDAP1. The mutation in the CMT2-102 pedigree was outside the canonical splice site sequences, emphasizing the importance of careful examination of available intronic sequences in exome sequence data.
Collapse
Affiliation(s)
- Marzieh Khani
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hanieh Taheri
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hosein Shamshiri
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Moazzeni
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - John Hardy
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK
| | - Jose Tomas Bras
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK
| | | | - Afagh Alavi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Shahriar Nafissi
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran.
| | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran.
| |
Collapse
|
5
|
Wu DW, Li Y, Yin X, Zhang B. A novel TFG c.793C>G mutation in a Chinese pedigree with Charcot-Marie-Tooth disease 2. Brain Behav 2020; 10:e01724. [PMID: 32666699 PMCID: PMC7507360 DOI: 10.1002/brb3.1724] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/20/2020] [Accepted: 05/25/2020] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Mutations within TFG gene were recently reported to cause Charcot-Marie-Tooth disease 2 (CMT2). However, only few pedigrees were documented so far. Here, we reported a Chinese CMT2 pedigree with 8 affected cases and a novel TFG mutation. METHODS Clinical evaluation and electrophysiological study were performed in all the affected individuals. Whole-exome sequencing was conducted, followed by the Sanger sequencing and co-segregation analysis to verify the variants. RESULTS All cases presented with a phenotype of CMT2, including slowly progressive symmetrical muscle atrophy and weakness predominantly in the distal limbs. Sensory loss in the distal limbs was present in the proband and his father. Age at onset ranged from 37 to 44 years, and was younger in male cases, compared with female cases. Nerve conduction study revealed normal motor nerve conduction velocity but decreased compound muscle action potential. Electromyography test revealed fibrillation potential and positive sharp waves. The creatine kinase activity was increased in all cases. After genetic investigations, we identified a novel TFG c.793C>G (p.Pro265Ala) mutation in the family. This mutation alters the conserved amino acid residue and is absent in 1000G, ExAC, dbSNP, EP6500, and 200 in-house controls. It co-segregated with the disease in the family. CONCLUSIONS Our report provided additional evidence that the heterozygous TFG mutations were associated with CMT2.
Collapse
Affiliation(s)
- Ding-Wen Wu
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Diagnosis and Treatment of Neonatal Diseases of Zhejiang Province, Hangzhou, China
| | - Yanfang Li
- Department of Pediatrics, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xinzhen Yin
- Department of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Baorong Zhang
- Department of Neurology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
6
|
Inherited motor-sensory neuropathy with upper limb predominance associated with the tropomyosin-receptor kinase fused gene. Neuromuscul Disord 2020; 30:227-231. [PMID: 32085962 DOI: 10.1016/j.nmd.2019.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/24/2019] [Accepted: 12/30/2019] [Indexed: 02/01/2023]
Abstract
The Tropomyosin-receptor kinase fused gene (TFG) encodes TFG which is expressed in spinal motor neurons, dorsal root ganglia and cranial nerve nuclei, and plays a role in the dynamics of the endoplasmic reticulum. Two dominant missense TFG mutations have previously been reported in limited geographical areas (Far East, Iran, China) in association with hereditary motor sensory neuropathy with proximal involvement (HMSN-P) of the four limbs, or with Charcot-Marie-Tooth disease type 2 (CMT2). The 60-year-old female proband belonging to a three-generation Italian family presented with an atypical neuropathy characterized by diffuse painful cramps and prominent motor-sensory impairment of the distal upper limbs. Her sural nerve biopsy showed chronic axonal neuropathy without active degeneration or regeneration. Targeted next-generation sequencing of a panel with 98 genes associated with inherited peripheral neuropathies/neuromuscular disorders identified three candidate genes: TFG, DHTKD1 and DCTN2. In the family, the disease co-segregated with the TFG p.(Gly269Val) variant. TFG should be considered in genetic testing of patients with heterogeneous inherited neuropathy, independently of their ethnic origin.
Collapse
|