1
|
de Sena Brandine G, Aston KI, Jenkins TG, Smith AD. Global effects of identity and aging on the human sperm methylome. Clin Epigenetics 2023; 15:127. [PMID: 37550724 PMCID: PMC10408082 DOI: 10.1186/s13148-023-01541-6] [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: 04/25/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND As the average age of fatherhood increases worldwide, so too does the need for understanding effects of aging in male germline cells. Molecular change, including epigenomic alterations, may impact offspring. Age-associated change to DNA cytosine methylation in the cytosine-guanine (CpG) context is a hallmark of aging tissues, including sperm. Prior studies have led to accurate models that predict a man's age based on specific methylation features in the DNA of sperm, but the relationship between aging and global DNA methylation in sperm remains opaque. Further clarification requires a more complete survey of the methylome with assessment of variability within and between individuals. RESULTS We collected sperm methylome data in a longitudinal study of ten healthy fertile men. We used whole-genome bisulfite sequencing of samples collected 10 to 18 years apart from each donor. We found that, overall, variability between donors far exceeds age-associated variation. After controlling for donor identity, we see significant age-dependent genome-wide change to the methylome. Notably, trends of change with age depend on genomic location or annotation, with contrasting signatures that correlate with gene density and proximity to centromeres and promoter regions. CONCLUSIONS We uncovered epigenetic signatures that reflect a stable process which begins in early adulthood, progressing steadily through most of the male lifespan, and warrants consideration in any future study of the aging sperm epigenome.
Collapse
Affiliation(s)
- Guilherme de Sena Brandine
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, USA
| | - Kenneth I Aston
- Andrology and IVF Laboratory, Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, USA
| | - Timothy G Jenkins
- Department of Cell Biology and Physiology, Brigham Young University, Provo, USA
| | - Andrew D Smith
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, USA.
| |
Collapse
|
2
|
Barbé L, Finkbeiner S. Genetic and Epigenetic Interplay Define Disease Onset and Severity in Repeat Diseases. Front Aging Neurosci 2022; 14:750629. [PMID: 35592702 PMCID: PMC9110800 DOI: 10.3389/fnagi.2022.750629] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Repeat diseases, such as fragile X syndrome, myotonic dystrophy, Friedreich ataxia, Huntington disease, spinocerebellar ataxias, and some forms of amyotrophic lateral sclerosis, are caused by repetitive DNA sequences that are expanded in affected individuals. The age at which an individual begins to experience symptoms, and the severity of disease, are partially determined by the size of the repeat. However, the epigenetic state of the area in and around the repeat also plays an important role in determining the age of disease onset and the rate of disease progression. Many repeat diseases share a common epigenetic pattern of increased methylation at CpG islands near the repeat region. CpG islands are CG-rich sequences that are tightly regulated by methylation and are often found at gene enhancer or insulator elements in the genome. Methylation of CpG islands can inhibit binding of the transcriptional regulator CTCF, resulting in a closed chromatin state and gene down regulation. The downregulation of these genes leads to some disease-specific symptoms. Additionally, a genetic and epigenetic interplay is suggested by an effect of methylation on repeat instability, a hallmark of large repeat expansions that leads to increasing disease severity in successive generations. In this review, we will discuss the common epigenetic patterns shared across repeat diseases, how the genetics and epigenetics interact, and how this could be involved in disease manifestation. We also discuss the currently available stem cell and mouse models, which frequently do not recapitulate epigenetic patterns observed in human disease, and propose alternative strategies to study the role of epigenetics in repeat diseases.
Collapse
Affiliation(s)
- Lise Barbé
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Steve Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Steve Finkbeiner,
| |
Collapse
|
3
|
Laaksovirta H, Launes J, Jansson L, Traynor BJ, Kaivola K, Tienari PJ. ALS in Finland. Neurol Genet 2022; 8:e665. [PMID: 35295181 PMCID: PMC8922337 DOI: 10.1212/nxg.0000000000000665] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/26/2022] [Indexed: 11/15/2022]
Abstract
Background and Objectives To analyze the frequencies of major genetic variants and the clinical features in Finnish patients with amyotrophic lateral sclerosis (ALS) with or without the C9orf72 hexanucleotide repeat expansion. Methods A cohort of patients with motor neuron disease was recruited between 1993 and 2020 at the Helsinki University Hospital and 2 second-degree outpatient clinics in Helsinki. Finnish ancestry patients with ALS fulfilled the diagnosis according to the revised El Escorial criteria and the Awaji-criteria. Two categories of familial ALS (FALS) were used. A patient was defined FALS-A if at least 1 first- or second-degree family member had ALS, and FALS-NP, if family members had additional neurologic or psychiatric endophenotypes. Results Of the 815 patients, 25% had FALS-A and 45% FALS-NP. C9orf72 expansion (C9pos) was found in 256 (31%) of all patients, in 58% of FALS-A category, in 48% of FALS-NP category, and in 23 or 17% of sporadic cases using the FALS-A or FALS-NP definition. C9pos or SOD1 p.D91A homozygosity was found in 328 (40%) of the 815 patients. We compared demographic and clinical characteristics between C9pos and patients with unknown cause of ALS (Unk). We found that the age at onset was significantly earlier and survival markedly shorter in the C9pos vs Unk patients with ALS. The shortest survival was found in bulbar-onset male C9pos patients, whereas the longest survival was found in Unk limb-onset males. Older age at onset associated consistently with shorter survival in C9pos and Unk patients in both limb-onset and bulbar-onset groups. There were no significant differences in the frequencies of bulbar-onset and limb-onset patients in C9pos and Unk groups. ALS-frontotemporal dementia (FTD) was more common in C9pos (17%) than in Unk (4%) patients, and of all patients with ALS-FTD, 70% were C9pos. Discussion These results provide further evidence for the short survival of C9orf72-associated ALS. A prominent role of the C9orf72 and SOD1 variants was found in the Finnish population. An unusually high frequency of C9pos was also found among patients with sporadic ALS. The enrichment of these 2 variants likely contributes to the high incidence of ALS in Finland.
Collapse
|
4
|
Gusella JF, Lee JM, MacDonald ME. Huntington's disease: nearly four decades of human molecular genetics. Hum Mol Genet 2021; 30:R254-R263. [PMID: 34169318 PMCID: PMC8490011 DOI: 10.1093/hmg/ddab170] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/16/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Huntington's disease (HD) is a devastating neurogenetic disorder whose familial nature and progressive course were first described in the 19th century but for which no disease-modifying treatment is yet available. Through the active participation of HD families, this disorder has acted as a flagship for the application of human molecular genetic strategies to identify disease genes, understand pathogenesis and identify rational targets for development of therapies.
Collapse
Affiliation(s)
- James F Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
- Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
5
|
Volpi E, Terenzi F, Bagnoli S, Latorraca S, Nacmias B, Sorbi S, Piacentini S, Ferrari C. Late-onset Huntington disease: An Italian cohort. J Clin Neurosci 2021; 86:58-63. [PMID: 33775347 DOI: 10.1016/j.jocn.2020.12.025] [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: 06/16/2020] [Revised: 12/11/2020] [Accepted: 12/20/2020] [Indexed: 11/25/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG expansion greater than 35 triplets in the IT-15 gene, with a clinical onset usually in the forties. Late-onset form of HD is defined as disease onset after the age of 59 years. The aim of the present study is to investigate the clinical-demographic features of Late-onset HD population (LoHD) in comparison to Classic-onset patients (CoHD). We analyzed a well-characterized Italian cohort of 127 HD patients, identifying 25.2% of LoHD cases. The mean age of onset was 65.9 and the mean length of pathological allele was 42.2. The 53.1% of LoHD patients had no family history of HD. No significant differences were observed in terms of gender, type of symptoms at disease onset, and clinical performance during the follow-up visits. The non-pathological allele resulted longer among LoHD patients. There is evidence that longer non-pathological allele is associated with a higher volume of basal ganglia, suggesting a possible protective role even in the onset of HD. In conclusion, LoHD patients in this Italian cohort were frequent, representing a quarter of total cases, and showed clinical features comparable to CoHD subjects. Due to the small sample size, further studies are needed to evaluate the influence of non-pathological alleles on disease onset.
Collapse
Affiliation(s)
- Eleonora Volpi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy.
| | - Federica Terenzi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Silvia Bagnoli
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | | | - Benedetta Nacmias
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy; IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Sandro Sorbi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy; IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Silvia Piacentini
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Camilla Ferrari
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| |
Collapse
|
6
|
Vishwakarma P, Agarwal S. Molecular spectrum and allelic frequency of different subtypes (1, 2, 3, 6 and 7) of Spinocerebellar ataxia in the Indian population. Intractable Rare Dis Res 2019; 8:193-197. [PMID: 31523597 PMCID: PMC6743434 DOI: 10.5582/irdr.2019.01063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Spinocerebellar ataxia (SCA) is a rare, heterogeneous genetic group of disorders with overlapping clinical features that arises as a result of the degeneration of Purkinje cells. The most prominent clinical feature of SCA is difficulty with whole body movements. The aim of the current study was to analyze the allelic frequency of normal repeat sizes in different SCA subtypes in the north Indian population. Blood samples were collected from 200 subjects, DNA was extracted, and then multiplex PCR and fragment analysis were performed using the ABI-310 genetic analyzer. The prevalent cytosine-adenine-guanine (CAG) repeat size or allelic frequency for SCA1, 2, 3 , 6, and 7 were 29 repeats (59%), 21 repeats (72.5%), 23 repeats (13.1%), 9 repeats (30%), and 3 repeats (75%), respectively. Results indicated that the normal repeats are shifting to lower or upper ranges in the Indian scenario, and similar findings have been reported in other previous studies. Thus, this and other studies have suggested that the normal range of repeats for various SCA in the Indian scenario needs to be redefined and should be confirmed by studies with larger samples and by functional studies.
Collapse
Affiliation(s)
| | - Sarita Agarwal
- Address correspondence to:Prof. Sarita Agarwal, Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India. 226014. E-mail:
| |
Collapse
|
7
|
Full sequence of mutant huntingtin 3'-untranslated region and modulation of its gene regulatory activity by endogenous microRNA. J Hum Genet 2019; 64:995-1004. [PMID: 31296921 DOI: 10.1038/s10038-019-0639-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/02/2019] [Accepted: 06/24/2019] [Indexed: 12/28/2022]
Abstract
Huntington's disease (HD) is caused by an expanded CAG trinucleotide repeat in the first exon of the huntingtin gene (HTT). Since the entire course of the disease starts from this dominant gain-of-function mutation, lowering total or mutant huntingtin mRNA/protein has emerged as an appealing therapeutic strategy. We reasoned that endogenous mechanisms underlying HTT gene regulation may inform strategies to target the source of the disease. As part of our investigation to understand how the expression of HTT is controlled, we performed (1) complete sequencing analysis for mutant HTT 3'-UTR and (2) unbiased screening assays to identify naturally-occurring miRNAs that could lower the HTT mRNA levels. By sequencing HD families inheriting the major European mutant haplotype, we determined the full sequence of HTT 3'-UTRs of the most frequent mutant (i.e., hap.01) and normal (i.e., hap.08) haplotypes, revealing 5 sites with alternative alleles. In subsequent miRNA activity assays using the full-length hap.01 and hap.08 3'-UTR reporter vectors and follow-up validation experiments, hsa-miR-4324 and hsa-miR-4756-5p significantly reduced HTT 3'-UTR reporter activity and endogenous HTT protein levels. However, those miRNAs did not show strong haplotype-specific effects. Nevertheless, our data highlighting full sequences of HTT 3'-UTR haplotypes, effects of miRNAs on HTT levels, and potential interaction sites provide rationale and promising targets for total and mutant-specific HTT lowering intervention strategies using endogenous and artificial miRNAs, respectively.
Collapse
|
8
|
Kaivola K, Kiviharju A, Jansson L, Rantalainen V, Eriksson JG, Strandberg TE, Laaksovirta H, Renton AE, Traynor BJ, Myllykangas L, Tienari PJ. C9orf72 hexanucleotide repeat length in older population: normal variation and effects on cognition. Neurobiol Aging 2019; 84:242.e7-242.e12. [PMID: 30979436 DOI: 10.1016/j.neurobiolaging.2019.02.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/08/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022]
Abstract
The hexanucleotide repeat expansion in C9orf72 is a common cause of amyotrophic lateral sclerosis/frontotemporal dementia and also rarely found in other psychiatric and neurodegenerative conditions. Alleles with >30 repeats are often considered an expansion, but the pathogenic repeat length threshold is still unclear. It is also unclear whether intermediate repeat length alleles (often defined either as 7-30 or 20-30 repeats) have clinically significant effects. We determined the C9orf72 repeat length distribution in 3142 older Finns (aged 60-104 years). The longest nonexpanded allele was 45 repeats. We found 7-45 repeats in 1036/3142 (33%) individuals, 20-45 repeats in 56/3142 (1.8%), 30-45 repeats in 12/3142 (0.38%), and expansion (>45 repeats) in 6/3142 (0.19%). There was no apparent clustering of neurodegenerative or psychiatric diseases in individuals with 30-45 repeats indicating that 30-45 repeats are not pathogenic. None of the 6 expansion carriers had a diagnosis of amyotrophic lateral sclerosis/frontotemporal dementia but 4 had a diagnosis of a neurodegenerative or psychiatric disease. Intermediate length alleles (categorized as 7-45 and 20-45 repeats) did not associate with Alzheimer's disease or cognitive impairment.
Collapse
Affiliation(s)
- Karri Kaivola
- Molecular Neurology, Research Programs Unit, Department of Neurology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland.
| | - Anna Kiviharju
- Molecular Neurology, Research Programs Unit, Department of Neurology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Lilja Jansson
- Molecular Neurology, Research Programs Unit, Department of Neurology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Ville Rantalainen
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
| | - Johan G Eriksson
- Folkhälsan Research Center, Helsinki, Finland; Department of General Practice and Primary Health Care, University of Helsinki, Helsinki University Hospital, Unit of General Practice, Helsinki, Finland; Department of General Practice and Primary Health Care, National Institute for Health and Welfare, Helsinki, Finland
| | - Timo E Strandberg
- Centre for Life Course Health Research, University of Oulu, Oulu, Finland; University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Hannu Laaksovirta
- Molecular Neurology, Research Programs Unit, Department of Neurology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Alan E Renton
- Department of Neuroscience, Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bryan J Traynor
- Laboratory of Neurogenetics, National Institutes on Aging, NIH, Bethesda, MD, USA
| | - Liisa Myllykangas
- Department of Pathology, University of Helsinki and HUSLAB, Helsinki University Hospital, Helsinki, Finland
| | - Pentti J Tienari
- Molecular Neurology, Research Programs Unit, Department of Neurology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
9
|
LaCroix AJ, Stabley D, Sahraoui R, Adam MP, Mehaffey M, Kernan K, Myers CT, Fagerstrom C, Anadiotis G, Akkari YM, Robbins KM, Gripp KW, Baratela WAR, Bober MB, Duker AL, Doherty D, Dempsey JC, Miller DG, Kircher M, Bamshad MJ, Nickerson DA, Mefford HC, Sol-Church K. GGC Repeat Expansion and Exon 1 Methylation of XYLT1 Is a Common Pathogenic Variant in Baratela-Scott Syndrome. Am J Hum Genet 2019; 104:35-44. [PMID: 30554721 PMCID: PMC6323552 DOI: 10.1016/j.ajhg.2018.11.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/05/2018] [Indexed: 01/25/2023] Open
Abstract
Baratela-Scott syndrome (BSS) is a rare, autosomal-recessive disorder characterized by short stature, facial dysmorphisms, developmental delay, and skeletal dysplasia caused by pathogenic variants in XYLT1. We report clinical and molecular investigation of 10 families (12 individuals) with BSS. Standard sequencing methods identified biallelic pathogenic variants in XYLT1 in only two families. Of the remaining cohort, two probands had no variants and six probands had only a single variant, including four with a heterozygous 3.1 Mb 16p13 deletion encompassing XYLT1 and two with a heterozygous truncating variant. Bisulfite sequencing revealed aberrant hypermethylation in exon 1 of XYLT1, always in trans with the sequence variant or deletion when present; both alleles were methylated in those with no identified variant. Expression of the methylated XYLT1 allele was severely reduced in fibroblasts from two probands. Southern blot studies combined with repeat expansion analysis of genome sequence data showed that the hypermethylation is associated with expansion of a GGC repeat in the XYLT1 promoter region that is not present in the reference genome, confirming that BSS is a trinucleotide repeat expansion disorder. The hypermethylated allele accounts for 50% of disease alleles in our cohort and is not present in 130 control subjects. Our study highlights the importance of investigating non-sequence-based alterations, including epigenetic changes, to identify the missing heritability in genetic disorders.
Collapse
Affiliation(s)
- Amy J LaCroix
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Deborah Stabley
- Nemours Biomedical Research Department, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Rebecca Sahraoui
- Nemours Biomedical Research Department, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA; Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Margaret P Adam
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA
| | - Michele Mehaffey
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Kelly Kernan
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | | | | | | | | | - Katherine M Robbins
- Nemours Biomedical Research Department, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Karen W Gripp
- Nemours Biomedical Research Department, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Wagner A R Baratela
- Division of Orthogenetics, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA; Instituto da Criança, Departamento de Pediatria, Universidade de São Paulo, São Paulo, SP Brazil
| | - Michael B Bober
- Division of Orthogenetics, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Angela L Duker
- Division of Orthogenetics, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Dan Doherty
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA
| | - Jennifer C Dempsey
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Daniel G Miller
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Martin Kircher
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Michael J Bamshad
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA
| | - Deborah A Nickerson
- Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA.
| | - Katia Sol-Church
- Nemours Biomedical Research Department, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA; Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| |
Collapse
|
10
|
Kay C, Collins JA, Wright GEB, Baine F, Miedzybrodzka Z, Aminkeng F, Semaka AJ, McDonald C, Davidson M, Madore SJ, Gordon ES, Gerry NP, Cornejo-Olivas M, Squitieri F, Tishkoff S, Greenberg JL, Krause A, Hayden MR. The molecular epidemiology of Huntington disease is related to intermediate allele frequency and haplotype in the general population. Am J Med Genet B Neuropsychiatr Genet 2018; 177:346-357. [PMID: 29460498 DOI: 10.1002/ajmg.b.32618] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 12/21/2017] [Indexed: 01/31/2023]
Abstract
Huntington disease (HD) is the most common monogenic neurodegenerative disorder in populations of European ancestry, but occurs at lower prevalence in populations of East Asian or black African descent. New mutations for HD result from CAG repeat expansions of intermediate alleles (IAs), usually of paternal origin. The differing prevalence of HD may be related to the rate of new mutations in a population, but no comparative estimates of IA frequency or the HD new mutation rate are available. In this study, we characterize IA frequency and the CAG repeat distribution in fifteen populations of diverse ethnic origin. We estimate the HD new mutation rate in a series of populations using molecular IA expansion rates. The frequency of IAs was highest in Hispanic Americans and Northern Europeans, and lowest in black Africans and East Asians. The prevalence of HD correlated with the frequency of IAs by population and with the proportion of IAs found on the HD-associated A1 haplotype. The HD new mutation rate was estimated to be highest in populations with the highest frequency of IAs. In European ancestry populations, one in 5,372 individuals from the general population and 7.1% of individuals with an expanded CAG repeat in the HD range are estimated to have a molecular new mutation. Our data suggest that the new mutation rate for HD varies substantially between populations, and that IA frequency and haplotype are closely linked to observed epidemiological differences in the prevalence of HD across major ancestry groups in different countries.
Collapse
Affiliation(s)
- Chris Kay
- Centre for Molecular Medicine Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Jennifer A Collins
- Centre for Molecular Medicine Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Galen E B Wright
- Centre for Molecular Medicine Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Fiona Baine
- Division of Human Genetics, Department of Pathology, University of Cape Town, South Africa.,Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Zosia Miedzybrodzka
- Medical Genetics Group, School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Folefac Aminkeng
- Centre for Molecular Medicine Therapeutics, University of British Columbia, Vancouver, BC, Canada.,Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Alicia J Semaka
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Cassandra McDonald
- Centre for Molecular Medicine Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Mark Davidson
- Medical Genetics Group, School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Steven J Madore
- Molecular Biology Group, Coriell Institute for Medical Research, Camden, New Jersey
| | - Erynn S Gordon
- Molecular Biology Group, Coriell Institute for Medical Research, Camden, New Jersey
| | - Norman P Gerry
- Molecular Biology Group, Coriell Institute for Medical Research, Camden, New Jersey
| | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Ferdinando Squitieri
- IRCCS Casa Sollievo della Sofferenza Hospital, Huntington and Rare Diseases Unit (CSS-Mendel Rome), San Giovanni Rotondo, Italy
| | - Sarah Tishkoff
- Department of Genetics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jacquie L Greenberg
- Division of Human Genetics, Department of Pathology, University of Cape Town, South Africa
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Michael R Hayden
- Centre for Molecular Medicine Therapeutics, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
11
|
|
12
|
Erives AJ. Evolving Notch polyQ tracts reveal possible solenoid interference elements. PLoS One 2017; 12:e0174253. [PMID: 28319202 PMCID: PMC5358852 DOI: 10.1371/journal.pone.0174253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 03/06/2017] [Indexed: 01/24/2023] Open
Abstract
Polyglutamine (polyQ) tracts in regulatory proteins are extremely polymorphic. As functional elements under selection for length, triplet repeats are prone to DNA replication slippage and indel mutations. Many polyQ tracts are also embedded within intrinsically disordered domains, which are less constrained, fast evolving, and difficult to characterize. To identify structural principles underlying polyQ tracts in disordered regulatory domains, here I analyze deep evolution of metazoan Notch polyQ tracts, which can generate alleles causing developmental and neurogenic defects. I show that Notch features polyQ tract turnover that is restricted to a discrete number of conserved “polyQ insertion slots”. Notch polyQ insertion slots are: (i) identifiable by an amphipathic “slot leader” motif; (ii) conserved as an intact C-terminal array in a 1-to-1 relationship with the N-terminal solenoid-forming ankyrin repeats (ARs); and (iii) enriched in carboxamide residues (Q/N), whose sidechains feature dual hydrogen bond donor and acceptor atoms. Correspondingly, the terminal loop and β-strand of each AR feature conserved carboxamide residues, which would be susceptible to folding interference by hydrogen bonding with residues outside the ARs. I thus suggest that Notch polyQ insertion slots constitute an array of AR interference elements (ARIEs). Notch ARIEs would dynamically compete with the delicate serial folding induced by adjacent ARs. Huntingtin, which harbors solenoid-forming HEAT repeats, also possesses a similar number of polyQ insertion slots. These results suggest that intrinsically disordered interference arrays featuring carboxamide and polyQ enrichment may constitute coupled proteodynamic modulators of solenoids.
Collapse
Affiliation(s)
- Albert J. Erives
- Department of Biology University of Iowa Iowa City, IA, United States of America
- * E-mail:
| |
Collapse
|
13
|
Kay C, Hayden MR, Leavitt BR. Epidemiology of Huntington disease. HANDBOOK OF CLINICAL NEUROLOGY 2017; 144:31-46. [DOI: 10.1016/b978-0-12-801893-4.00003-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
14
|
The Complexity of Clinical Huntington's Disease: Developments in Molecular Genetics, Neuropathology and Neuroimaging Biomarkers. ADVANCES IN NEUROBIOLOGY 2017; 15:129-161. [PMID: 28674980 DOI: 10.1007/978-3-319-57193-5_5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterised by extensive neuronal loss in the striatum and cerebral cortex, and a triad of clinical symptoms affecting motor, cognitive/behavioural and mood functioning. The mutation causing HD is an expansion of a CAG tract in exon 1 of the HTT gene. This chapter provides a multifaceted overview of the clinical complexity of HD. We explore recent directions in molecular genetics including the identification of loci that are genetic modifiers of HD that could potentially reveal therapeutic targets beyond the HTT gene transcript and protein. The variability of clinical symptomatology in HD is considered alongside recent findings of variability in cellular and neurochemical changes in the striatum and cerebral cortex in human brain. We review evidence from structural neuroimaging methods of progressive changes of striatum, cerebral cortex and white matter in pre-symptomatic and symptomatic HD, with a particular focus on the potential identification of neuroimaging biomarkers that could be used to test promising disease-specific and modifying treatments. Finally we provide an overview of completed clinical trials in HD and future therapeutic developments.
Collapse
|
15
|
Ni CL, Seth D, Fonseca FV, Wang L, Xiao TS, Gruber P, Sy MS, Stamler JS, Tartakoff AM. Polyglutamine Tract Expansion Increases S-Nitrosylation of Huntingtin and Ataxin-1. PLoS One 2016; 11:e0163359. [PMID: 27658206 PMCID: PMC5033456 DOI: 10.1371/journal.pone.0163359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/07/2016] [Indexed: 11/19/2022] Open
Abstract
Expansion of the polyglutamine (polyQ) tract in the huntingtin (Htt) protein causes Huntington’s disease (HD), a fatal inherited movement disorder linked to neurodegeneration in the striatum and cortex. S-nitrosylation and S-acylation of cysteine residues regulate many functions of cytosolic proteins. We therefore used a resin-assisted capture approach to identify these modifications in Htt. In contrast to many proteins that have only a single S-nitrosylation or S-acylation site, we identified sites along much of the length of Htt. Moreover, analysis of cells expressing full-length Htt or a large N-terminal fragment of Htt shows that polyQ expansion strongly increases Htt S-nitrosylation. This effect appears to be general since it is also observed in Ataxin-1, which causes spinocerebellar ataxia type 1 (SCA1) when its polyQ tract is expanded. Overexpression of nitric oxide synthase increases the S-nitrosylation of normal Htt and the frequency of conspicuous juxtanuclear inclusions of Htt N-terminal fragments in transfected cells. Taken together with the evidence that S-nitrosylation of Htt is widespread and parallels polyQ expansion, these subcellular changes show that S-nitrosylation affects the biology of this protein in vivo.
Collapse
Affiliation(s)
- Chun-Lun Ni
- Cell Biology Program, Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Divya Seth
- Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Fabio Vasconcelos Fonseca
- Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Liwen Wang
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Tsan Sam Xiao
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Phillip Gruber
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Man-Sun Sy
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Jonathan S. Stamler
- Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Alan M. Tartakoff
- Cell Biology Program, Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
- * E-mail:
| |
Collapse
|
16
|
Abstract
The past 2 decades have witnessed an explosion in molecular neurogenetics and neurobiology. The aggres sive application of new techniques to the dominantly inherited disorder, Huntington's disease, defined the standard for the positional cloning of human genetic diseases. A parallel effort from neurobiologists and clinicians has set the stage for the development of potential new therapies for the disease. Along the winding road to finding the gene, many lessons were learned by clinicians and scientists alike. The next decade of research offers new challenges and rewards for those involved with this disease. The Neuroscientist 1:51- 58, 1995
Collapse
Affiliation(s)
- Anne B. Young
- Neurology Service, Massachusetts General Hospital Department
of Neurology, Harvard Medical School Boston, Massachusetts
| |
Collapse
|
17
|
Lewis SEM, Kumar K. The paternal genome and the health of the assisted reproductive technology child. Asian J Androl 2016; 17:616-22. [PMID: 25926606 PMCID: PMC4492053 DOI: 10.4103/1008-682x.153301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
As a number of children born by assisted reproductive technology (ART) are increasing each year across the developed world, the health of such offspring is a matter of public concern. Does the integrity of the paternal genome impact on offspring health? In societal terms, as birth rates fall, and the Western population become unsustainable, do the benefits outweigh the costs of creating and providing for this ART conceived subpopulation? There are little data to date to answer these questions. The long-term health of such children has largely been ignored, and success measured only by early (prebirth) outcomes such as embryo quality or pregnancy. However, there are powerful paradigms such as ageing and smoking that give vital clues as to the potential impact of unhealthy spermatozoa on disease risk, mental and physical health, fertility and mortality of these offspring.
Collapse
Affiliation(s)
- Sheena E M Lewis
- Centre for Public Health, Queen's University Belfast, Grosvenor Road, BT12 6BJ,NI, UK
| | | |
Collapse
|
18
|
Sun YM, Zhang YB, Wu ZY. Huntington's Disease: Relationship Between Phenotype and Genotype. Mol Neurobiol 2016; 54:342-348. [PMID: 26742514 DOI: 10.1007/s12035-015-9662-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/17/2015] [Indexed: 12/19/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant inherited neurodegenerative disease with the typical manifestations of involuntary movements, psychiatric and behavior disorders, and cognitive impairment. It is caused by the dynamic mutation in CAG triplet repeat number in exon 1 of huntingtin (HTT) gene. The symptoms of HD especially the age at onset are related to the genetic characteristics, both the CAG triplet repeat and the modified factors. Here, we reviewed the recent advancement on the genotype-phenotype relationship of HD, mainly focus on the characteristics of different expanded CAG repeat number, genetic modifiers, and CCG repeat number in the 3' end of CAG triplet repeat and their effects on the phenotype. We also reviewed the special forms of HD (juvenile HD, atypical onset HD, and homozygous HD) and their phenotype-genotype correlations. The review will aid clinicians to predict the onset age and disease course of HD, give the genetic counseling, and accelerate research into the HD mechanism.
Collapse
Affiliation(s)
- Yi-Min Sun
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yan-Bin Zhang
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Zhi-Ying Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China.
| |
Collapse
|
19
|
Gan SR, Ni W, Dong Y, Wang N, Wu ZY. Population genetics and new insight into range of CAG repeats of spinocerebellar ataxia type 3 in the Han Chinese population. PLoS One 2015; 10:e0134405. [PMID: 26266536 PMCID: PMC4534407 DOI: 10.1371/journal.pone.0134405] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/08/2015] [Indexed: 12/21/2022] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3), also called Machado-Joseph disease (MJD), is one of the most common SCAs worldwide and caused by a CAG repeat expansion located in ATXN3 gene. Based on the CAG repeat numbers, alleles of ATXN3 can be divided into normal alleles (ANs), intermediate alleles (AIs) and expanded alleles (AEs). It was controversial whether the frequency of large normal alleles (large ANs) is related to the prevalence of SCA3 or not. And there were huge chaos in the comprehension of the specific numbers of the range of CAG repeats which is fundamental for genetic analysis of SCA3. To illustrate these issues, we made a novel CAG repeat ladder to detect CAG repeats of ATXN3 in 1003 unrelated Chinese normal individuals and studied haplotypes defined by three single nucleotide polymorphisms (SNPs) closed to ATXN3. We found that the number of CAG repeats ranged from 13 to 49, among them, 14 was the most common number. Positive skew, the highest frequency of large ANs and 4 AIs which had never been reported before were found. Also, AEs and large ANs shared the same haplotypes defined by the SNPs. Based on these data and other related studies, we presumed that de novo mutations of ATXN3 emerging from large ANs are at least one survival mechanisms of mutational ATXN3 and we can redefine the range of CAG repeats as: ANs≤44, 45 ≤AIs ≤49 and AEs≥50.
Collapse
Affiliation(s)
- Shi-Rui Gan
- Department of Neurology and Research center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Wang Ni
- Department of Neurology and Research center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Dong
- Department of Neurology and Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ning Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Zhi-Ying Wu
- Department of Neurology and Research center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai, China
| |
Collapse
|
20
|
Uhlmann WR, Peñaherrera MS, Robinson WP, Milunsky JM, Nicholson JM, Albin RL. Biallelic mutations in huntington disease: A new case with just one affected parent, review of the literature and terminology. Am J Med Genet A 2015; 167A:1152-60. [DOI: 10.1002/ajmg.a.37009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/22/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Wendy R. Uhlmann
- Division of Molecular Medicine and Genetics; Department of Internal Medicine; University of Michigan; Ann Arbor Michigan
- Department of Human Genetics; University of Michigan; Ann Arbor Michigan
| | - Maria S. Peñaherrera
- Department of Medical Genetics; University of British Columbia; Vancouver British Columbia
- Child and Family Research Institute; Vancouver British Columbia
| | - Wendy P. Robinson
- Department of Medical Genetics; University of British Columbia; Vancouver British Columbia
- Child and Family Research Institute; Vancouver British Columbia
| | | | - Jane M. Nicholson
- Division of Molecular Medicine and Genetics; Department of Internal Medicine; University of Michigan; Ann Arbor Michigan
- Department of Obstetrics and Gynecology; University of Michigan; Ann Arbor Michigan
| | - Roger L. Albin
- Department of Neurology; University of Michigan; Ann Arbor Michigan
- VA Ann Arbor Healthcare System; Geriatrics Research, Education, and Clinical Center; Ann Arbor Michigan
| |
Collapse
|
21
|
Ramos EM, Gillis T, Mysore JS, Lee J, Gögele M, D'Elia Y, Pichler I, Sequeiros J, Pramstaller PP, Gusella JF, MacDonald ME, Alonso I. Haplotype analysis of the 4p16.3 region in Portuguese families with Huntington's disease. Am J Med Genet B Neuropsychiatr Genet 2015; 168B:135-43. [PMID: 25656686 PMCID: PMC5006842 DOI: 10.1002/ajmg.b.32289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 11/25/2014] [Indexed: 12/12/2022]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder characterized by involuntary choreic movements, cognitive impairment, and behavioral changes, caused by the expansion of an unstable CAG repeat in HTT. We characterized the genetic diversity of the HD mutation by performing an extensive haplotype analysis of ∼1Mb region flanking HTT in over 300 HD families of Portuguese origin. We observed that haplotype A, marked by HTT delta2642, was enriched in HD chromosomes and carried the two largest expansions reported in the Portuguese population. However, the most frequent HD haplotype B carried one of the largest (+12 CAGs) expansions, which resulted in an allele class change to full penetrance. Despite having a normal CAG distribution skewed to the higher end of the range, these two core haplotypes had similar expanded CAG repeat sizes compared to the other major core haplotypes (C and D) and there was no statistical difference in transmitted repeat instability across haplotypes. We observed a diversity of HTT region haplotypes in both normal and expanded chromosomes, representative of more than one ancestral chromosome underlying HD in Portugal, where multiple independent events on distinct chromosome 4 haplotypes have given rise to expansion into the pathogenic range.
Collapse
Affiliation(s)
- Eliana Marisa Ramos
- Center for Human Genetic ResearchMassachusetts General HospitalBostonMassachusettsUSA,UnIGENeIBMC–Institute for Molecular and Cell BiologyUniversity of PortoPortoPortugal
| | - Tammy Gillis
- Center for Human Genetic ResearchMassachusetts General HospitalBostonMassachusettsUSA
| | - Jayalakshmi S. Mysore
- Center for Human Genetic ResearchMassachusetts General HospitalBostonMassachusettsUSA
| | - Jong‐Min Lee
- Center for Human Genetic ResearchMassachusetts General HospitalBostonMassachusettsUSA
| | - Martin Gögele
- Center for BiomedicineEuropean Academy of Bozen/Bolzano (EURAC)BolzanoItaly
| | - Yuri D'Elia
- Center for BiomedicineEuropean Academy of Bozen/Bolzano (EURAC)BolzanoItaly
| | - Irene Pichler
- Center for BiomedicineEuropean Academy of Bozen/Bolzano (EURAC)BolzanoItaly
| | - Jorge Sequeiros
- UnIGENeIBMC–Institute for Molecular and Cell BiologyUniversity of PortoPortoPortugal,CGPPIBMC–Institute for Molecular and Cell BiologyUniversity of PortoPortoPortugal,ICBAS–Instituto de Ciências Biomédicas Abel SalazarUniversity of PortoPortoPortugal
| | - Peter P. Pramstaller
- Center for BiomedicineEuropean Academy of Bozen/Bolzano (EURAC)BolzanoItaly,Department of NeurologyCentral HospitalBolzanoItaly,Department of NeurologyUniversity of LübeckLübeckGermany
| | - James F. Gusella
- Center for Human Genetic ResearchMassachusetts General HospitalBostonMassachusettsUSA
| | - Marcy E. MacDonald
- Center for Human Genetic ResearchMassachusetts General HospitalBostonMassachusettsUSA
| | - Isabel Alonso
- UnIGENeIBMC–Institute for Molecular and Cell BiologyUniversity of PortoPortoPortugal,CGPPIBMC–Institute for Molecular and Cell BiologyUniversity of PortoPortoPortugal,ICBAS–Instituto de Ciências Biomédicas Abel SalazarUniversity of PortoPortoPortugal
| |
Collapse
|
22
|
|
23
|
Jenkins TG, Aston KI, Trost C, Farley J, Hotaling JM, Carrell DT. Intra-sample heterogeneity of sperm DNA methylation. ACTA ACUST UNITED AC 2014; 21:313-9. [DOI: 10.1093/molehr/gau115] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/18/2014] [Indexed: 12/24/2022]
|
24
|
Semaka A, Kay C, Belfroid RDM, Bijlsma EK, Losekoot M, van Langen IM, van Maarle MC, Oosterloo M, Hayden MR, van Belzen MJ. A new mutation for Huntington disease following maternal transmission of an intermediate allele. Eur J Med Genet 2014; 58:28-30. [PMID: 25464109 DOI: 10.1016/j.ejmg.2014.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/12/2014] [Indexed: 10/24/2022]
Abstract
New mutations for Huntington disease (HD) originate from CAG repeat expansion of intermediate alleles (27-35 CAG). Expansions of such alleles into the pathological range (≥ 36 CAG) have been exclusively observed in paternal transmission. We report the occurrence of a new mutation that defies the paternal expansion bias normally observed in HD. A maternal intermediate allele with 33 CAG repeats expanded in transmission to 48 CAG repeats causing a de novo case of HD in the family. Retrospectively, the mother presented with cognitive decline, but HD was never considered in the differential diagnosis. She was diagnosed with dementia and testing for HD was only performed after her daughter had been diagnosed. This observation of an intermediate allele expanding into the full penetrance HD range after maternal transmission has important implications for genetic counselling of females with intermediate repeats.
Collapse
Affiliation(s)
- Alicia Semaka
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - René D M Belfroid
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Monique Losekoot
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Irene M van Langen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Merel C van Maarle
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Mayke Oosterloo
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Martine J van Belzen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| |
Collapse
|
25
|
Bean L, Bayrak-Toydemir P. American College of Medical Genetics and Genomics Standards and Guidelines for Clinical Genetics Laboratories, 2014 edition: technical standards and guidelines for Huntington disease. Genet Med 2014; 16:e2. [PMID: 25356969 DOI: 10.1038/gim.2014.146] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 09/15/2014] [Indexed: 11/09/2022] Open
Abstract
Huntington disease is an autosomal-dominant neurodegenerative disease of mid-life onset caused by expansion of a polymorphic trinucleotide (CAG) repeat. Variable penetrance for alleles carrying 36-39 repeats has been noted, but the disease appears fully penetrant when the repeat numbers are >40. An abnormal CAG repeat may expand, contract, or be stably transmitted when passed from parent to child. Assays used to diagnose Huntington disease must be optimized to ensure the accurate and unambiguous quantitation of CAG repeat length. This document provides an overview of Huntington disease and methodological considerations for Huntington disease testing. Examples of laboratory reports are also included.
Collapse
Affiliation(s)
- Lora Bean
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Pinar Bayrak-Toydemir
- Department of Pathology, University of Utah School of Medicine and ARUP Laboratories, Salt Lake City, Utah, USA
| |
Collapse
|
26
|
Jenkins TG, Aston KI, Pflueger C, Cairns BR, Carrell DT. Age-associated sperm DNA methylation alterations: possible implications in offspring disease susceptibility. PLoS Genet 2014; 10:e1004458. [PMID: 25010591 PMCID: PMC4091790 DOI: 10.1371/journal.pgen.1004458] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 05/09/2014] [Indexed: 11/18/2022] Open
Abstract
Recent evidence demonstrates a role for paternal aging on offspring disease susceptibility. It is well established that various neuropsychiatric disorders (schizophrenia, autism, etc.), trinucleotide expansion associated diseases (myotonic dystrophy, Huntington's, etc.) and even some forms of cancer have increased incidence in the offspring of older fathers. Despite strong epidemiological evidence that these alterations are more common in offspring sired by older fathers, in most cases the mechanisms that drive these processes are unclear. However, it is commonly believed that epigenetics, and specifically DNA methylation alterations, likely play a role. In this study we have investigated the impact of aging on DNA methylation in mature human sperm. Using a methylation array approach we evaluated changes to sperm DNA methylation patterns in 17 fertile donors by comparing the sperm methylome of 2 samples collected from each individual 9-19 years apart. With this design we have identified 139 regions that are significantly and consistently hypomethylated with age and 8 regions that are significantly hypermethylated with age. A representative subset of these alterations have been confirmed in an independent cohort. A total of 117 genes are associated with these regions of methylation alterations (promoter or gene body). Intriguingly, a portion of the age-related changes in sperm DNA methylation are located at genes previously associated with schizophrenia and bipolar disorder. While our data does not establish a causative relationship, it does raise the possibility that the age-associated methylation of the candidate genes that we observe in sperm might contribute to the increased incidence of neuropsychiatric and other disorders in the offspring of older males. However, further study is required to determine whether, and to what extent, a causative relationship exists.
Collapse
Affiliation(s)
- Timothy G. Jenkins
- Andrology and IVF Laboratories, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Kenneth I. Aston
- Andrology and IVF Laboratories, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Christian Pflueger
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Bradley R. Cairns
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail: (BRC); (DTC)
| | - Douglas T. Carrell
- Andrology and IVF Laboratories, Department of Surgery, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail: (BRC); (DTC)
| |
Collapse
|
27
|
The Ginkgo biloba Extract EGb 761 Modulates Proteasome Activity and Polyglutamine Protein Aggregation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:940186. [PMID: 25002904 PMCID: PMC4068065 DOI: 10.1155/2014/940186] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 04/27/2014] [Accepted: 05/08/2014] [Indexed: 11/18/2022]
Abstract
The standardized Ginkgo biloba extract EGb 761 has well-described antioxidative activities and effects on different cytoprotective signaling pathways. Consequently, a potential use of EGb 761 in neurodegenerative diseases has been proposed. A common characteristic feature of a variety of such disorders is the pathologic formation of protein aggregates, suggesting a crucial role for protein homeostasis. In this study, we show that EGb 761 increased the catalytic activity of the proteasome and enhanced protein degradation in cultured cells. We further investigated this effect in a cellular model of Huntington's disease (HD) by employing cells expressing pathologic variants of a polyglutamine protein (polyQ protein). We show that EGb 761 affected these cells by (i) increasing proteasome activity and (ii) inducing a more efficient degradation of aggregation-prone proteins. These results demonstrate a novel activity of EGb 761 on protein aggregates by enhancing proteasomal protein degradation, suggesting a therapeutic use in neurodegenerative disorders with a disturbed protein homeostasis.
Collapse
|
28
|
Semaka A, Hayden M. Evidence-based genetic counselling implications for Huntington disease intermediate allele predictive test results. Clin Genet 2014; 85:303-11. [DOI: 10.1111/cge.12324] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/18/2013] [Accepted: 11/18/2013] [Indexed: 11/29/2022]
Affiliation(s)
- A. Semaka
- Centre for Molecular Medicine and Therapeutics; University of British Columbia; Vancouver British Columbia Canada
| | - M.R. Hayden
- Centre for Molecular Medicine and Therapeutics; University of British Columbia; Vancouver British Columbia Canada
| |
Collapse
|
29
|
Vázquez-Mojena Y, Laguna-Salvia L, Laffita-Mesa JM, González-Zaldívar Y, Almaguer-Mederos LE, Rodríguez-Labrada R, Almaguer-Gotay D, Zayas-Feria P, Velázquez-Pérez L. Genetic features of Huntington disease in Cuban population: Implications for phenotype, epidemiology and predictive testing. J Neurol Sci 2013; 335:101-4. [DOI: 10.1016/j.jns.2013.08.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 10/26/2022]
|
30
|
Semaka A, Kay C, Doty CN, Collins JA, Tam N, Hayden MR. High frequency of intermediate alleles on Huntington disease-associated haplotypes in British Columbia's general population. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:864-71. [PMID: 24038799 DOI: 10.1002/ajmg.b.32193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 07/11/2013] [Indexed: 11/08/2022]
Abstract
Intermediate alleles (27-35 CAG, IAs) for Huntington disease (HD) usually do not confer the disease phenotype but are prone to CAG repeat instability. Consequently, offspring are at-risk of inheriting an expanded allele in the HD range (≥36 CAG). IAs that expand into a new mutation have been hypothesized to be more susceptible to instability compared to IAs identified on the non-HD side of a family from the general population. Frequency estimates for IAs are limited and have largely been determined using clinical samples of HD or related disorders, which may result in an ascertainment bias. This study aimed to establish the frequency of IAs in a sample of a British Columbia's (B.C.) general population with no known association to HD and examine the haplotype of new mutation and general population IAs. CAG sizing was performed on 1,600 DNA samples from B.C.'s general population. Haplotypes were determined using 22 tagging SNPs across the HTT gene. 5.8% of individuals were found to have an IA, of which 60% were on HD-associated haplotypes. There was no difference in the haplotype distribution of new mutation and general population IAs. These findings suggest that IAs are relatively frequent in the general population and are often found on haplotypes associated with expanded CAG lengths. There is likely no difference in the propensity of new mutation and general population IAs to expand into the disease range given that they are both found on disease-associated haplotypes. These findings have important implications for clinical practice.
Collapse
Affiliation(s)
- Alicia Semaka
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | | | | | | | | | | |
Collapse
|
31
|
Semaka A, Kay C, Doty C, Collins JA, Bijlsma EK, Richards F, Goldberg YP, Hayden MR. CAG size-specific risk estimates for intermediate allele repeat instability in Huntington disease. J Med Genet 2013; 50:696-703. [PMID: 23896435 DOI: 10.1136/jmedgenet-2013-101796] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION New mutations for Huntington disease (HD) occur due to CAG repeat instability of intermediate alleles (IA). IAs have between 27 and 35 CAG repeats, a range just below the disease threshold of 36 repeats. While they usually do not confer the HD phenotype, IAs are prone to paternal germline CAG repeat instability. Consequently, they may expand into the HD range upon transmission to the next generation, producing a new mutation. Quantified risk estimates for IA repeat instability are extremely limited but needed to inform clinical practice. METHODS Using small-pool PCR of sperm DNA from Caucasian men, we examined the frequency and magnitude of CAG repeat instability across the entire range of intermediate CAG sizes. The CAG size-specific risk estimates generated are based on the largest sample size ever examined, including 30 IAs and 18 198 sperm. RESULTS Our findings demonstrate a significant risk of new mutations. While all intermediate CAG sizes demonstrated repeat expansion into the HD range, alleles with 34 and 35 CAG repeats were associated with the highest risk of a new mutation (2.4% and 21.0%, respectively). IAs with ≥33 CAG repeats showed a dramatic increase in the frequency of instability and a switch towards a preponderance of repeat expansions over contractions. CONCLUSIONS These data provide novel insights into the origins of new mutations for HD. The CAG size-specific risk estimates inform clinical practice and provide accurate risk information for persons who receive an IA predictive test result.
Collapse
Affiliation(s)
- Alicia Semaka
- Department of Medical Genetics, Centre for Molecular Medicine & Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Zheng YM, Li L, Zhou LM, Le F, Cai LY, Yu P, Zhu YR, Liu XZ, Wang LY, Li LJ, Lou YY, Xu XR, Lou HY, Zhu XM, Sheng JZ, Huang HF, Jin F. Alterations in the frequency of trinucleotide repeat dynamic mutations in offspring conceived through assisted reproductive technology. Hum Reprod 2013; 28:2570-80. [PMID: 23861482 DOI: 10.1093/humrep/det294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
STUDY QUESTION How does the frequency of trinucleotide repeat dynamic mutations in offspring conceived through assisted reproductive technology (ART) compare with the frequency of these mutations in control offspring conceived from spontaneous pregnancies? SUMMARY ANSWER There is a slight increase in dynamic mutation instability in offspring conceived through ART compared with the naturally conceived offspring. WHAT IS KNOWN ALREADY There is evidence to suggest that ART can increase the risk of birth defects and karyotypic abnormalities. However, the accumulating evidence of an association between ART and de novo genetic aberrations is controversial. STUDY DESIGN, SIZE, DURATION A prospective clinical observational study was performed on 246 families recruited from an in vitro fertilisation (IVF) centre at a tertiary-care, university-affiliated teaching hospital from 2008 to 2012. The study included 147 ART families [75 IVF and 72 intracytoplasmic sperm injection (ICSI)] in the study group and 99 natural-conception families in the control group. PARTICIPANTS, SETTING, METHODS Parental, umbilical cord and infant peripheral blood samples were collected, and the trinucleotide repeats of the ATN1, AR, ATXN1, ATXN3, Huntington, DMPK and FMR-1 genes were investigated between the generations; these genes were chosen due to their ability to undergo dynamic mutation. The frequencies and sizes of the mutational repeats, as well as the intergenerational instability, were measured. MAIN RESULTS AND THE ROLE OF CHANCE In 2466 transmissions identified in the ART offspring, 2.11% (n = 52/2466) of the alleles were unstable upon transmission, while in the control group offspring, the frequency of dynamic mutation was 0.77% (n = 10/1300); this difference was statistically significant (P < 0.01). The unstable transmission alleles were detected in 32 (2.48%) of the 1288 alleles from the IVF offspring and in 20 (1.70%) of the 1178 alleles from the ICSI offspring; both of these frequencies were significantly different from that of naturally conceived offspring (0.77%) (P < 0.01 and P < 0.05, respectively). However, there were no significant differences in the sizes of the mutational repeats or in the rates of expansion or contraction among the three groups (P > 0.05). The repeat copy numbers of the examined genes were found to be within the normal ranges in all parents and infants. LIMITATIONS, REASONS FOR CAUTION One strength of our study is the relatively large sample size; we were able to detect mutations in seven common dynamic genes, and this large sample size allowed us to detect unstable alleles. Although we observed a clear alteration in the frequency of dynamic mutation in the ART offspring compared with controls, further studies are urgently needed to confirm this observation and determine the cause of this phenomenon. WIDER IMPLICATIONS OF THE FINDINGS DNA microsatellite analysis provides an important tool to assess genomic instability. In this study, we report an association between ART and the frequency of dynamic mutation. The instability could be a reflection of the core infertility problem, the controlled ovarian hyperstimulation and/or the in vitro culture conditions.
Collapse
Affiliation(s)
- Ying-Ming Zheng
- Department of Reproductive Endocrinology, Zhejiang University School of Medicine, Zhejiang, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Losekoot M, van Belzen MJ, Seneca S, Bauer P, Stenhouse SAR, Barton DE. EMQN/CMGS best practice guidelines for the molecular genetic testing of Huntington disease. Eur J Hum Genet 2013; 21:480-6. [PMID: 22990145 PMCID: PMC3641377 DOI: 10.1038/ejhg.2012.200] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Huntington disease (HD) is caused by the expansion of an unstable polymorphic trinucleotide (CAG)n repeat in exon 1 of the HTT gene, which translates into an extended polyglutamine tract in the protein. Laboratory diagnosis of HD involves estimation of the number of CAG repeats. Molecular genetic testing for HD is offered in a wide range of laboratories both within and outside the European community. In order to measure the quality and raise the standard of molecular genetic testing in these laboratories, the European Molecular Genetics Quality Network has organized a yearly external quality assessment (EQA) scheme for molecular genetic testing of HD for over 10 years. EQA compares a laboratory's output with a fixed standard both for genotyping and reporting of the results to the referring physicians. In general, the standard of genotyping is very high but the clarity of interpretation and reporting of the test result varies more widely. This emphasizes the need for best practice guidelines for this disorder. We have therefore developed these best practice guidelines for genetic testing for HD to assist in testing and reporting of results. The analytical methods and the potential pitfalls of molecular genetic testing are highlighted and the implications of the different test outcomes for the consultand and his or her family members are discussed.
Collapse
Affiliation(s)
- Monique Losekoot
- Department of Clinical Genetics, Laboratory for Diagnostic Genome Analysis, Leiden University Medical Centre, Leiden, The Netherlands.
| | | | | | | | | | | |
Collapse
|
34
|
Savić Pavićević D, Miladinović J, Brkušanin M, Šviković S, Djurica S, Brajušković G, Romac S. Molecular genetics and genetic testing in myotonic dystrophy type 1. BIOMED RESEARCH INTERNATIONAL 2013; 2013:391821. [PMID: 23586035 PMCID: PMC3613064 DOI: 10.1155/2013/391821] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 02/05/2013] [Indexed: 12/29/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is the most common adult onset muscular dystrophy, presenting as a multisystemic disorder with extremely variable clinical manifestation, from asymptomatic adults to severely affected neonates. A striking anticipation and parental-gender effect upon transmission are distinguishing genetic features in DM1 pedigrees. It is an autosomal dominant hereditary disease associated with an unstable expansion of CTG repeats in the 3'-UTR of the DMPK gene, with the number of repeats ranging from 50 to several thousand. The number of CTG repeats broadly correlates with both the age-at-onset and overall severity of the disease. Expanded DM1 alleles are characterized by a remarkable expansion-biased and gender-specific germline instability, and tissue-specific, expansion-biased, age-dependent, and individual-specific somatic instability. Mutational dynamics in male and female germline account for observed anticipation and parental-gender effect in DM1 pedigrees, while mutational dynamics in somatic tissues contribute toward the tissue-specificity and progressive nature of the disease. Genetic test is routinely used in diagnostic procedure for DM1 for symptomatic, asymptomatic, and prenatal testing, accompanied with appropriate genetic counseling and, as recommended, without predictive information about the disease course. We review molecular genetics of DM1 with focus on those issues important for genetic testing and counseling.
Collapse
Affiliation(s)
- Dušanka Savić Pavićević
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Jelena Miladinović
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Miloš Brkušanin
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Saša Šviković
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Svetlana Djurica
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Goran Brajušković
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Stanka Romac
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| |
Collapse
|
35
|
Baine FK, Kay C, Ketelaar ME, Collins JA, Semaka A, Doty CN, Krause A, Greenberg LJ, Hayden MR. Huntington disease in the South African population occurs on diverse and ethnically distinct genetic haplotypes. Eur J Hum Genet 2013; 21:1120-7. [PMID: 23463025 DOI: 10.1038/ejhg.2013.2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/12/2012] [Accepted: 12/28/2012] [Indexed: 11/09/2022] Open
Abstract
Huntington disease (HD) is a neurodegenerative disorder resulting from the expansion of a CAG trinucleotide repeat in the huntingtin (HTT) gene. Worldwide prevalence varies geographically with the highest figures reported in populations of European ancestry. HD in South Africa has been reported in Caucasian, black and mixed subpopulations, with similar estimated prevalence in the Caucasian and mixed groups and a lower estimate in the black subpopulation. Recent studies have associated specific HTT haplotypes with HD in distinct populations. Expanded HD alleles in Europe occur predominantly on haplogroup A (specifically high-risk variants A1/A2), whereas in East Asian populations, HD alleles are associated with haplogroup C. Whether specific HTT haplotypes associate with HD in black Africans and how these compare with haplotypes found in European and East Asian populations remains unknown. The current study genotyped the HTT region in unaffected individuals and HD patients from each of the South African subpopulations, and haplotypes were constructed. CAG repeat sizes were determined and phased to haplotype. Results indicate that HD alleles from Caucasian and mixed patients are predominantly associated with haplogroup A, signifying a similar European origin for HD. However, in black patients, HD occurs predominantly on haplogroup B, suggesting several distinct origins of the mutation in South Africa. The absence of high-risk variants (A1/A2) in the black subpopulation may also explain the reported low prevalence of HD. Identification of haplotypes associated with HD-expanded alleles is particularly relevant to the development of population-specific therapeutic targets for selective suppression of the expanded HTT transcript.
Collapse
Affiliation(s)
- Fiona K Baine
- 1] Division of Human Genetics, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa [2] Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
de Die-Smulders CEM, de Wert GMWR, Liebaers I, Tibben A, Evers-Kiebooms G. Reproductive options for prospective parents in families with Huntington's disease: clinical, psychological and ethical reflections. Hum Reprod Update 2013; 19:304-15. [PMID: 23377865 DOI: 10.1093/humupd/dms058] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Huntington's disease (HD) is an autosomal dominant neurodegenerative late onset disorder. This review of reproductive options aims to increase reproductive confidence and to prevent suffering in relation to family planning around HD and possibly other late onset neurodegenerative disorders. METHODS Selected relevant literature and own views and experiences as clinical geneticists, psychologists and ethicists have been used. RESULTS Possible options, with emphasis on prenatal diagnosis (PD) and preimplantation genetic diagnosis (PGD) to prevent the transmission of HD to the next generation, are described and discussed. They are formally presented in a decision tree, taking into account the presence or absence of a fully penetrant allele (FPA), a reduced penetrant allele (RPA) or an intermediate allele (IA). A table compares invasive and non-invasive PD and PGD. From a psychological perspective, the complex process of counselling and decision-making regarding reproductive options is discussed. Special attention is paid to the decision to avoid the transmission of the mutation and to the confrontation and coping of a mutation-free child growing up with a parent developing disease symptoms. From an ethical point of view, reflections on both PD and PGD are brought forward taking into account the difference between FPA, RPA and IA, direct testing or exclusion testing and taking into account the welfare of the child in the context of medically assisted reproduction. CONCLUSION Recommendations and suggestions for good clinical practice in the reproductive care for HD families are formulated.
Collapse
Affiliation(s)
- C E M de Die-Smulders
- Department of Clinical Genetics, Maastricht University Medical Centre, Joseph Bechlaan 113, Maastricht, The Netherlands.
| | | | | | | | | |
Collapse
|
37
|
Semaka A, Balneaves LG, Hayden MR. "Grasping the grey": patient understanding and interpretation of an intermediate allele predictive test result for Huntington disease. J Genet Couns 2012; 22:200-17. [PMID: 22903792 DOI: 10.1007/s10897-012-9533-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 07/30/2012] [Indexed: 10/28/2022]
Abstract
Since the discovery of the genetic mutation underlying Huntington disease (HD) and the development of predictive testing, the genetics of HD has generally been described as straightforward; an individual receives either mutation-positive or negative predictive test results. However, in actuality, the genetics of HD is complex and a small proportion of individuals receive an unusual predictive test result called an intermediate allele (IA). Unlike mutation-positive or negative results, IAs confer uncertain clinical implications. While individuals with an IA will usually not develop HD, there remains an unknown risk for their children and future generations to develop the disorder. The purpose of this study was to explore how individuals understood and interpreted their IA result. Interviews were conducted with 29 individuals who received an IA result and 8 medical genetics service providers. Interviews were analyzed using the constant comparative method and the coding procedures of grounded theory. Many participants had difficulty "Grasping the Grey" (i.e. understanding and interpreting their IA results) and their family experience, beliefs, expectations, and genetic counseling influenced the degree of this struggle. The theoretical model developed informs clinical practice regarding IAs, ensuring that this unique subset of patients received appropriate education, support, and counseling.
Collapse
Affiliation(s)
- A Semaka
- Department of Medical Genetics, Centre for Molecular Medicine & Therapeutics, University of British Columbia, 950 West 28th Ave, Vancouver, BC V5Z 4H4, Canada.
| | | | | |
Collapse
|
38
|
Kameya T, Abe K, Aoki M, Itoyama Y. A family with mild clinical manifestations of spinocerebellar ataxia type 1 (SCA1): correlation with smaller CAG repeats. Eur J Neurol 2011; 2:349-55. [DOI: 10.1111/j.1468-1331.1995.tb00138.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
39
|
Abstract
It has been more than 17 years since the causative mutation for Huntington's disease was discovered as the expansion of the triplet repeat in the N-terminal portion of the Huntingtin (HTT) gene. In the intervening time, researchers have discovered a great deal about Huntingtin's involvement in a number of cellular processes. However, the role of Huntingtin in the key pathogenic mechanism leading to neurodegeneration in the disease process has yet to be discovered. Here, we review the body of knowledge that has been uncovered since gene discovery and include discussions of the HTT gene, CAG triplet repeat expansion, HTT expression, protein features, posttranslational modifications, and many of its known protein functions and interactions. We also highlight potential pathogenic mechanisms that have come to light in recent years.
Collapse
Affiliation(s)
- Karen N McFarland
- Department of Neurology, University of Florida, Gainesville, FL 32610-0236, USA.
| | | |
Collapse
|
40
|
Krobitsch S, Kazantsev AG. Huntington's disease: From molecular basis to therapeutic advances. Int J Biochem Cell Biol 2010; 43:20-4. [PMID: 21056115 DOI: 10.1016/j.biocel.2010.10.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 10/26/2010] [Accepted: 10/27/2010] [Indexed: 12/15/2022]
Abstract
Huntington's disease is an autosomal dominant genetic neurodegenerative disorder, which is characterized by progressive motor dysfunction, emotional disturbances, dementia, and weight loss. The disease is caused by pathological CAG-triplet repeat extension(s), encoding polyglutamines, within the gene product, huntingtin. Huntingtin is ubiquitously expressed through the body and is a protein of uncertain molecular function(s). Mutant huntingtin, containing pathologically extended polyglutamines causes the earliest and most dramatic neuropathologic changes in the neostriatum and cerebral cortex. Extended polyglutamines confer structural conformational changes to huntingtin, which gains novel properties, resulting in aberrant interactions with multiple cellular components. The diverse and variable aberrations mediated by mutant huntingtin perturb many cellular functions essential for neuronal homeostasis and underlie pleiotropic mechanisms of Huntington's disease pathogenesis. The only approved drug for Huntington's disease is a symptomatic treatment, tetrabenazine; thus, novel neuroprotective strategies, slowing, blocking and possibly reversing disease progression, are vital for developing effective therapies.
Collapse
Affiliation(s)
- Sylvia Krobitsch
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany.
| | | |
Collapse
|
41
|
Abstract
Trinucleotide expansion underlies several human diseases. Expansion occurs during multiple stages of human development in different cell types, and is sensitive to the gender of the parent who transmits the repeats. Repair and replication models for expansions have been described, but we do not know whether the pathway involved is the same under all conditions and for all repeat tract lengths, which differ among diseases. Currently, researchers rely on bacteria, yeast and mice to study expansion, but these models differ substantially from humans. We need now to connect the dots among human genetics, pathway biochemistry and the appropriate model systems to understand the mechanism of expansion as it occurs in human disease.
Collapse
|
42
|
Sequeiros J, Ramos EM, Cerqueira J, Costa MC, Sousa A, Pinto-Basto J, Alonso I. Large normal and reduced penetrance alleles in Huntington disease: instability in families and frequency at the laboratory, at the clinic and in the population. Clin Genet 2010; 78:381-7. [DOI: 10.1111/j.1399-0004.2010.01388.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
43
|
Semaka A, Collins JA, Hayden MR. Unstable familial transmissions of Huntington disease alleles with 27-35 CAG repeats (intermediate alleles). Am J Med Genet B Neuropsychiatr Genet 2010; 153B:314-20. [PMID: 19455596 DOI: 10.1002/ajmg.b.30970] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
There are inconsistent reports regarding the likelihood of repeat instability for alleles with 27-35 CAG repeats in the Huntington disease (HD) gene. We have examined the intergenerational stability of such intermediate alleles in 51 families from the University of British Columbia's DNA and Tissue Bank for Huntington Disease Research (UBC-HD Databank). A total of 181 transmissions were identified, with 30% (n = 54/181) of the alleles being unstable upon transmission. The unstable transmissions included both expansions (n = 37) and contractions (n = 17) of CAG size. Of the expanded alleles, 68% (n = 25/37) expanded into the HD range (>36 CAG). Therefore, 14% (n = 25/181) of the 27-35 CAG allele transmissions examined expanded into the disease-associated range resulting in a new mutation for HD. Significantly, of these new mutations, 40% (n = 10/25) originated from an allele with 35 CAG repeats with CAG repeat expansions ranging from +1 CAG to +23 CAG. The proportion of new mutations in the UBC-HD Databank is consistent with the most recent new mutation rate for HD, estimated to be at least 10%. The observed difference in the stability of HD intermediate allele transmissions in this data set and in other studies may be a reflection of a small sample size. Alternately, these inconsistencies may indicate an underlying difference in genetic factors which influence repeat instability between the different populations examined. Additional studies determining the frequency and magnitude of repeat instability in this CAG repeat range and factors that influence instability are urgently needed. Until we understand the clinical implications of HD alleles with 27-35 CAG repeats and establish reliable risks of instability, we should exercise caution when translating these results to the clinic.
Collapse
Affiliation(s)
- A Semaka
- Centre for Molecular Medicine and Therapeutics, Vancouver, Canada
| | | | | |
Collapse
|
44
|
Hendricks AE, Latourelle JC, Lunetta KL, Cupples LA, Wheeler V, MacDonald ME, Gusella JF, Myers RH. Estimating the probability of de novo HD cases from transmissions of expanded penetrant CAG alleles in the Huntington disease gene from male carriers of high normal alleles (27-35 CAG). Am J Med Genet A 2009; 149A:1375-81. [PMID: 19507258 PMCID: PMC2724761 DOI: 10.1002/ajmg.a.32901] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Huntington disease (HD) is a dominantly transmitted neurodegenerative disorder that arises from expansion of a CAG trinucleotide repeat on chromosome 4p16.3. CAG repeat allele lengths are defined as fully penetrant at >or=40, reduced penetrance at 36-39, high normal at 27-35, and normal at or=36) to offspring. We estimated the conditional probability of an offspring inheriting an expanded penetrant allele given a father with a high normal allele by applying probability definitions and rules to estimates of HD incidence, paternal birth rate, frequency of de novo HD, and frequency of high normal alleles in the general population. The estimated probability that a male high normal allele carrier will have an offspring with an expanded penetrant allele ranges from 1/6,241 to 1/951. These estimates may be useful in genetic counseling for male high normal allele carriers.
Collapse
Affiliation(s)
- Audrey E Hendricks
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts 02118, USA
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Brocklebank D, Gayán J, Andresen JM, Roberts SA, Young AB, Snodgrass SR, Penney JB, Ramos-Arroyo MA, Cha JJ, Rosas HD, Hersch SM, Feigin A, Cherny SS, Wexler NS, Housman DE, Cardon LR. Repeat instability in the 27-39 CAG range of the HD gene in the Venezuelan kindreds: Counseling implications. Am J Med Genet B Neuropsychiatr Genet 2009; 150B:425-9. [PMID: 18712713 PMCID: PMC4636008 DOI: 10.1002/ajmg.b.30826] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The instability of the CAG repeat size of the HD gene when transmitted intergenerationally has critical implications for genetic counseling practices. In particular, CAG repeats between 27 and 35 have been the subject of debate based on small samples. To address this issue, we analyzed allelic instability in the Venezuelan HD kindreds, the largest and most informative families ascertained for HD. We identified 647 transmissions. Our results indicate that repeats in the 27-35 CAG range are highly stable. Out of 69 transmitted alleles in this range, none expand into any penetrant ranges. Contrastingly, 14% of alleles transmitted from the incompletely penetrant range (36-39 CAGs) expand into the completely penetrant range, characterized by alleles with 40 or more CAG repeats. At least 12 of the 534 transmissions from the completely penetrant range contract into the incompletely penetrant range of 36-39 CAG repeats. In these kindreds, none of the individuals with 27-39 CAGs were symptomatic, even though they ranged in age from 11 to 82 years. We expect these findings to be helpful in updating genetic counseling practices.
Collapse
Affiliation(s)
- D Brocklebank
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Conley ME, Dobbs AK, Farmer DM, Kilic S, Paris K, Grigoriadou S, Coustan-Smith E, Howard V, Campana D. Primary B cell immunodeficiencies: comparisons and contrasts. Annu Rev Immunol 2009; 27:199-227. [PMID: 19302039 DOI: 10.1146/annurev.immunol.021908.132649] [Citation(s) in RCA: 281] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sophisticated genetic tools have made possible the identification of the genes responsible for most well-described immunodeficiencies in the past 15 years. Mutations in Btk, components of the pre-B cell and B cell receptor (lambda5, Igalpha, Igbeta), or the scaffold protein BLNK account for approximately 90% of patients with defects in early B cell development. Hyper-IgM syndromes result from mutations in CD40 ligand, CD40, AID, or UNG in 70-80% of affected patients. Rare defects in ICOS or CD19 can result in a clinical picture that is consistent with common variable immunodeficiency, and as many as 10% of patients with this disorder have heterozygous amino acid substitutions in TACI. For all these disorders, there is considerable clinical heterogeneity in patients with the same mutation. Identifying the genetic and environmental factors that influence the clinical phenotype may enhance patient care and our understanding of normal B cell development.
Collapse
Affiliation(s)
- Mary Ellen Conley
- Department of Pediatrics, University of Tennessee College of Medicine, Memphis, Tennessee 38163, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Herishanu YO, Parvari R, Pollack Y, Shelef I, Marom B, Martino T, Cannella M, Squitieri F. Huntington disease in subjects from an Israeli Karaite community carrying alleles of intermediate and expanded CAG repeats in the HTT gene: Huntington disease or phenocopy? J Neurol Sci 2009; 277:143-6. [DOI: 10.1016/j.jns.2008.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 10/01/2008] [Accepted: 11/10/2008] [Indexed: 11/29/2022]
|
48
|
Genetics and Pathogenesis of Inherited Ataxias and Spastic Paraplegias. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 652:263-96. [DOI: 10.1007/978-90-481-2813-6_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
49
|
Sato T, Miura M, Yamada M, Yoshida T, Wood JD, Yazawa I, Masuda M, Suzuki T, Shin RM, Yau HJ, Liu FC, Shimohata T, Onodera O, Ross CA, Katsuki M, Takahashi H, Kano M, Aosaki T, Tsuji S. Severe neurological phenotypes of Q129 DRPLA transgenic mice serendipitously created by en masse expansion of CAG repeats in Q76 DRPLA mice. Hum Mol Genet 2008; 18:723-36. [PMID: 19039037 PMCID: PMC2638829 DOI: 10.1093/hmg/ddn403] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
We herein provide a thorough description of new transgenic mouse models for dentatorubral–pallidoluysian atrophy (DRPLA) harboring a single copy of the full-length human mutant DRPLA gene with 76 and 129 CAG repeats. The Q129 mouse line was unexpectedly obtained by en masse expansion based on the somatic instability of 76 CAG repeats in vivo. The mRNA expression levels of both Q76 and Q129 transgenes were each 80% of that of the endogenous mouse gene, whereas only the Q129 mice exhibited devastating progressive neurological phenotypes similar to those of juvenile-onset DRPLA patients. Electrophysiological studies of the Q129 mice demonstrated age-dependent and region-specific presynaptic dysfunction in the globus pallidus and cerebellum. Progressive shrinkage of distal dendrites of Purkinje cells and decreased currents through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and γ-aminobutyrate type A receptors in CA1 neurons were also observed. Neuropathological studies of the Q129 mice revealed progressive brain atrophy, but no obvious neuronal loss, associated with massive neuronal intranuclear accumulation (NIA) of mutant proteins with expanded polyglutamine stretches starting on postnatal day 4, whereas NIA in the Q76 mice appeared later with regional specificity to the vulnerable regions of DRPLA. Expression profile analyses demonstrated age-dependent down-regulation of genes, including those relevant to synaptic functions and CREB-dependent genes. These results suggest that neuronal dysfunction without neuronal death is the essential pathophysiologic process and that the age-dependent NIA is associated with nuclear dysfunction including transcriptional dysregulations. Thus, our Q129 mice should be highly valuable for investigating the mechanisms of disease pathogenesis and therapeutic interventions.
Collapse
Affiliation(s)
- Toshiya Sato
- Department of Comparative and Experimental Medicine, Brain Research Institute, Niigata University, Niigata, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
The ultimate goal for Huntington's disease (HD) therapeutics is to develop disease-modifying neuroprotective therapies that can delay or prevent illness in those who are at genetic risk and can slow progression in those who are affected clinically. Neuroprotection is the preservation of neuronal structure, function, and viability, and neuroprotective therapy is thus targeted at the underlying pathology of HD, rather than at its specific symptoms. Preclinical target discovery research in HD is identifying numerous distinct targets, along with options for modulating them, with some proceeding into large-scale efficacy studies in early symptomatic HD subjects. The first pilot studies of neuroprotective compounds in premanifest HD are also soon to begin. This review discusses the opportunities for neuroprotection in HD, clinical methodology in premanifest and manifest HD, the clinical assessment of neuroprotection, molecular targets and therapeutic leads, and the current state of clinical development.
Collapse
Affiliation(s)
- Steven M Hersch
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129-4404, USA.
| | | |
Collapse
|