Wayne Silverman

Kennedy Krieger Institute, Baltimore, Maryland, United States

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Publications (106)455.63 Total impact

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    ABSTRACT: We examined the contribution of candidate genes for Alzheimer’s disease (AD) on Chromosome 21 and other chromosomes to differences in Aβ peptide levels in a cohort of adults with DS, a population at high risk for AD. Participants were 254 non-demented adults with Down syndrome, 30-78 years of age. Genomic DNA was genotyped using an Illumina GoldenGate custom array. We used linear regression to examine differences in levels of Aβ peptides associated with the number of risk alleles, adjusting for age, sex, level of intellectual disability, race/ethnicity and the presence of the APOE ε4 allele. For Aβ42 levels, the strongest gene-wise association was found for a SNP on CAHLM1; for Aβ40 levels the strongest gene-wise associations were found for SNPs in IDE and SOD1, while the strongest gene-wise associations with levels of the Aβ42/Aβ40 ratio were found for SNPs in SORCS1. Broadly classified, variants in these genes may influence APP processing (CALHM1, IDE), vesicular trafficking (SORCS1), and response to oxidative stress (SOD1).
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    ABSTRACT: Background Adults with Down syndrome (DS) are at risk of developing dementia and cognitive assessment is a fundamental part of the diagnostic process. Previously, we developed a Rapid Assessment for Developmental Disabilities (RADD), a brief, broadly focused direct test of cognition. In the current report, we assess whether the RADD is sensitive to dementia in DS and the degree to which it compares with other cognitive measures of dementia in this population.Methods In a sample of 114 individuals with DS, with dementia diagnosed in 62%, the RADD was compared with the Dementia Questionnaire for Mentally Retarded Persons (DMR), the Bristol Activities of Daily Living Scale, Severe Impairment Battery (SIB), and the Brief Praxis Test (BPT).ResultsThe RADD showed predicted effects across intellectual disability (ID) levels and dementia status (p < 0.001). Six-month test-retest reliability for the subset of individuals without dementia was high (r(41) = 0.95, p < 0.001). Criterion-referenced validity was demonstrated by correlations between RADD scores and ID levels based upon prior intelligence testing and clinical diagnoses (rs(114) = 0.67, p = 0.001) and with other measures of cognitive skills, such as the BPT, SIB, and DMR-Sum of Cognitive scores (range 0.84 through 0.92). Using receiver operating characteristic curves for groups varying in pre-morbid severity of ID, the RADD exhibited high sensitivity (0.87) and specificity (0.81) in discriminating among individuals with and without dementia, although sensitivity was somewhat lower (0.73) for the subsample of dementia cases diagnosed no more than 2 years prior to their RADD assessment.Conclusion Taken together, findings indicated that the RADD, a relatively brief, easy-to-administer test for cognitive function assessment across ID levels and dementia status, would be a useful component of cognitive assessments for adults with DS, including assessments explicitly focused on dementia.
    Journal of Intellectual Disability Research 05/2015; DOI:10.1111/jir.12200 · 2.41 Impact Factor
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    ABSTRACT: In the United States, estimates indicate there are between 250,000 and 400,000 individuals with Down syndrome (DS), and nearly all will develop Alzheimer's disease (AD) pathology starting in their 30s. With the current lifespan being 55 to 60 years, approximately 70% will develop dementia, and if their life expectancy continues to increase, the number of individuals developing AD will concomitantly increase. Pathogenic and mechanistic links between DS and Alzheimer's prompted the Alzheimer's Association to partner with the Linda Crnic Institute for Down Syndrome and the Global Down Syndrome Foundation at a workshop of AD and DS experts to discuss similarities and differences, challenges, and future directions for this field. The workshop articulated a set of research priorities: (1) target identification and drug development, (2) clinical and pathological staging, (3) cognitive assessment and clinical trials, and (4) partnerships and collaborations with the ultimate goal to deliver effective disease-modifying treatments. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 12/2014; 11(6). DOI:10.1016/j.jalz.2014.10.007 · 17.47 Impact Factor
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    Alzheimer's and Dementia 07/2014; 10(4):P471. DOI:10.1016/j.jalz.2014.05.675 · 17.47 Impact Factor
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    ABSTRACT: People with intellectual disability (ID) are living longer than ever before, raising concerns about old-age associated disorders. Dementia is among the most serious of these disorders, and theories relating cognitive reserve to risk predict that older adults with ID should be particularly vulnerable. Previous estimates of relative risk for dementia associated with ID have been inconsistent, and the present analyses examined the possible influence of variation in diagnostic criteria on findings. As expected, relaxation in the stringency of case definition for adults with ID increased relative risk, underscoring the importance of developing valid criteria for defining mild cognitive impairment, early dementia, and distinguishing between the two in adults with ID. Once available, these standards will contribute to more effective evidence-based planning.
    Journal of Policy and Practice in Intellectual Disabilities 09/2013; 10(3). DOI:10.1111/jppi.12042 · 0.97 Impact Factor
  • Sharon J Krinsky-McHale, Wayne Silverman
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    ABSTRACT: Individuals with intellectual disability (ID) are now living longer with the majority of individuals reaching middle and even "old age." As a consequence of this extended longevity they are vulnerable to the same age-associated health problems as elderly adults in the general population without ID. This includes dementia, a general term referring to a variety of diseases and conditions causing substantial loss of cognitive ability and functional declines; adults with Down syndrome are at especially high risk. A great deal of recent effort has focused on the very earliest detectable indicators of decline (and even prodromal stages of dementia-causing diseases). A condition called mild cognitive impairment (MCI) has been conceptually defined as a decline in functioning that is more severe than expected with typical brain aging but not severe enough to meet criteria for a diagnosis of dementia. Consensus criteria for both dementia and MCI have been developed for typically developing adults but are of limited applicability for adults with ID, given their pre-existing cognitive impairments. Early diagnosis will continue to be of growing importance, both to support symptomatic treatment and to prevent irreversible neuropathology when interventions are developed to slow or halt the progression of underlying disease. While the intellectual and developmental disabilities field has for some time recognized the need to develop best-practices for the diagnosis of MCI and dementia, there remains a pressing need for empirically based assessment methods and classification criteria. © 2013 Wiley Periodicals, Inc. Dev Disabil Res Rev 2013;18:31-42.
    Developmental Disabilities Research Reviews 08/2013; 18(1):31-42. DOI:10.1002/ddrr.1126 · 0.29 Impact Factor
  • Wayne Silverman, Marsha R Mailick
    Developmental Disabilities Research Reviews 08/2013; 18(1):1-5. DOI:10.1002/ddrr.1122 · 0.29 Impact Factor
  • Anna J Esbensen, Marsha R Mailick, Wayne Silverman
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    ABSTRACT: Abstract Parental characteristics were significant predictors of health, functional abilities, and behavior problems in adults with Down syndrome (n = 75) over a 22-year time span, controlling for initial levels and earlier changes in these outcomes. Lower levels of behavior problems were predicted by improvements in maternal depressive symptoms. Higher levels of functional abilities were predicted by prior measures of and improvements in maternal depressive symptoms. Better health was predicted by prior measures of maternal depressive symptoms, paternal positive psychological well-being, relationship quality between fathers and their adult children, and improvements in maternal positive psychological well-being. Dementia status was also predicted by parental characteristics. The study suggests the importance of the family context for healthy aging in adults with Down syndrome.
    American Journal on Intellectual and Developmental Disabilities 07/2013; 118(4):294-309. DOI:10.1352/1944-7558-118.4.294 · 2.08 Impact Factor
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    ABSTRACT: BACKGROUND: In individuals with Down syndrome, virtually all structures of the eye have some abnormality, which likely diminishes vision. We examined basic vision functions in adults with Down syndrome. MATERIALS AND METHODS: Participants completed a battery of psychophysical tests that probed a comprehensive array of visual functions. The performance of adults with Down syndrome was compared with younger and older adults without intellectual disability. RESULTS: Adults with Down syndrome had significant vision deficits, reduced sensitivity across spatial frequencies and temporal modulation rates, reduced stereopsis, impaired vernier acuity and anomalies in colour discrimination. The pattern of deficits observed was similar to those seen by researchers examining adults with Alzheimer's disease. CONCLUSIONS: Our findings suggest that a common mechanism may be responsible for the pattern of deficits observed, possibly the presence of Alzheimer's disease neuropathology in the visual association cortex. We also showed that individuals with mild to moderate intellectual disability are capable of participating in studies employing state-of-the-art psychophysical procedures. This has wider implications in terms of their ability to participate in research that use similar techniques.
    Journal of Applied Research in Intellectual Disabilities 06/2013; DOI:10.1111/jar.12062 · 1.38 Impact Factor
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    ABSTRACT: The chromosome 21 gene RCAN1, encoding a modulator of the calcineurin (CaN) phosphatase, is a candidate gene for contributing to cognitive disability in people with Down syndrome (DS; trisomy 21). To develop a physiologically relevant model for studying the biochemistry of RCAN1 and its contribution to DS, we generated bacterial artificial chromosome-transgenic (BAC-Tg) mouse lines containing the human RCAN1 gene with a C-terminal HA-FLAG epitope tag incorporated by recombineering. The BAC-Tg was expressed at levels only moderately higher than the native Rcan1 gene: approximately 1.5-fold in RCAN1 (BAC-Tg1) and twofold in RCAN1 (BAC-Tg2). Affinity purification of the RCAN1 protein complex from brains of these mice revealed a core complex of RCAN1 with CaN, glycogen synthase kinase 3-beta (Gsk3b), and calmodulin, with substoichiometric components, including LOC73419. The BAC-Tg mice are fully viable, but long-term synaptic potentiation is impaired in proportion to BAC-Tg dosage in hippocampal brain slices from these mice. RCAN1 can act as a tumor suppressor in some systems, but we found that the RCAN1 BAC-Tg did not reduce mammary cancer growth when present at a low copy number in Tp53;WAP-Cre mice. This work establishes a useful mouse model for investigating the biochemistry and dose-dependent functions of the RCAN1 protein in vivo.
    Mammalian Genome 10/2012; 24(1-2). DOI:10.1007/s00335-012-9436-9 · 2.88 Impact Factor
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    ABSTRACT: A public-private partnership to establish biomarkers of dementia in Down's syndrome could aid the development of preventive therapies for the dementia associated with both Down's syndrome and Alzheimer's disease, based on the apparent common pathogenic role of amyloid precursor protein in the two conditions.
    dressNature Reviews Drug Discovery 08/2012; 11(9):655-6. DOI:10.1038/nrd3822 · 37.23 Impact Factor
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    Current Gerontology and Geriatrics Research 07/2012; 2012:412536. DOI:10.1155/2012/412536
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    ABSTRACT: Previously, we established that short-term T lymphocyte cultures from people with Down syndrome (DS) and dementia (Alzheimer's disease) had shorter telomeres than did those from age- and sex-matched people with DS only, quantified as significantly reduced numbers of signals of peptide nucleic acid (PNA) telomere probes in whole metaphases [Jenkins et al. (2008); Neurosci Lett 440:340-343] as well as reduced telomere probe light intensity values in interphases [Jenkins et al. (2010); Neurobiol Aging 31:765-771]. We now describe shorter telomere length in adults with DS and mild cognitive impairment (MCI) compared to age- and sex-matched individuals with DS without MCI. Telomere length is quantified by reduced telomere signal numbers and shorter chromosome 1 telomeres measured in micrometers (microns). These findings were in agreement with quantitative light intensity measurements of chromosome 1 and chromosome 21 PNA telomere probes with and without the use of a "normalizing ratio" involving the fluorescence exhibited by a PNA probe for centromere 2, and with the use of light intensity measurements of interphase preparations. Most importantly, the distributions of chromosome 1 telomere lengths (in microns) were completely non-overlapping for adults with and without MCI, indicating that this measure has great promise as a biomarker for MCI as well as dementia in this population.
    American Journal of Medical Genetics Part B Neuropsychiatric Genetics 07/2012; 159B(5):598-604. DOI:10.1002/ajmg.b.32066 · 3.27 Impact Factor
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    ABSTRACT: A myriad of ophthalmic disorders is associated with the phenotype of Down syndrome including strabismus, cataracts, and refractive errors potentially resulting in significant visual impairment. Ophthalmic sequelae have been extensively studied in children and adolescents with Down syndrome but less often in older adults. In-depth review of medical records of older adults with Down syndrome indicated that ophthalmic disorders were common. Cataracts were the most frequent ophthalmic disorder reported, followed by refractive errors, strabismus, and presbyopia. Severity of intellectual disability was unrelated to the presence of ophthalmic disorders. Also, ophthalmic disorders were associated with lower vision-dependent functional and cognitive abilities, although not to the extent that was expected. The high prevalence of ophthalmic disorders highlights the need for periodic evaluations and individualized treatment plans for adults with Down syndrome, in general, but especially when concerns are identified.
    Current Gerontology and Geriatrics Research 04/2012; 2012:974253. DOI:10.1155/2012/974253
  • Edmund C Jenkins, Lingling Ye, Wayne P Silverman
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    ABSTRACT: We have observed evidence of increased telomere shortening in short-term T-lymphocyte cultures following freezing and thawing of the original inoculum obtained by ficoll-paque gradient centrifugation, compared to T-lymphocytes that were cultured immediately without freezing and thawing from the same blood sample from 3 female and 3 male adults. Because freezing may have similar effects on other cell types, and because telomere shortening may only manifest its effects after many years or decades, we suggest there is a pressing need for evaluation of the effects of freezing on any cells envisioned for clinical applications, including embryo implantation.
    Cryobiology 03/2012; 65(1):72-3. DOI:10.1016/j.cryobiol.2012.03.005 · 1.64 Impact Factor
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    ABSTRACT: Background/Aims. Genetic variants that affect estrogen activity may influence the risk of Alzheimer's disease (AD). In women with Down syndrome, we examined the relation of polymorphisms in hydroxysteroid-17beta-dehydrogenase (HSD17B1) to age at onset and risk of AD. HSD17B1 encodes the enzyme 17β-hydroxysteroid dehydrogenase (HSD1), which catalyzes the conversion of estrone to estradiol. Methods. Two hundred and thirty-eight women with DS, nondemented at baseline, 31-78 years of age, were followed at 14-18-month intervals for 4.5 years. Women were genotyped for 5 haplotype-tagging single-nucleotide polymorphisms (SNPs) in the HSD17B1 gene region, and their association with incident AD was examined. Results. Age at onset was earlier, and risk of AD was elevated from two- to threefold among women homozygous for the minor allele at 3 SNPs in intron 4 (rs676387), exon 6 (rs605059), and exon 4 in COASY (rs598126). Carriers of the haplotype TCC, based on the risk alleles for these three SNPs, had an almost twofold increased risk of developing AD (hazard ratio = 1.8, 95% CI, 1.1-3.1). Conclusion. These findings support experimental and clinical studies of the neuroprotective role of estrogen.
    Current Gerontology and Geriatrics Research 03/2012; 2012:361218. DOI:10.1155/2012/361218
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    ABSTRACT: Genetic variants that affect estrogen activity may influence the risk of Alzheimer's disease (AD). We examined the relation of polymorphisms in the gene for the estrogen receptor-beta (ESR2) to the risk of AD in women with Down syndrome. Two hundred and forty-nine women with Down syndrome, 31-70 years of age and nondemented at baseline, were followed at 14- to 18-month intervals for 4 years. Women were genotyped for 13 single-nucleotide polymorphisms (SNPs) in the ESR2 gene, and their association with AD incidence was examined. Among postmenopausal women, we found a 2-fold increase in the risk of AD for women carrying 1 or 2 copies of the minor allele at 3 SNPs in introns seven (rs17766755) and six (rs4365213 and rs12435857) and 1 SNP in intron eight (rs4986938) of ESR2. These findings support a role for estrogen and its major brain receptors in modulating susceptibility to AD in women.
    Dementia and Geriatric Cognitive Disorders 12/2011; 32(4):241-9. DOI:10.1159/000334522 · 2.81 Impact Factor
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    ABSTRACT: CYP17 and CYP19 are involved in the peripheral synthesis of estrogens, and polymorphisms in CYP17 and CYP19 have been associated with increased risk of estrogen-related disorders. Women with Down syndrome (DS) have early onset and high risk for Alzheimer's disease (AD). We conducted a prospective community-based cohort study to examine the relationship between SNPs in CYP17 and CYP19 and cumulative incidence of AD, hormone levels and sex hormone binding globulin in women with DS. Two hundred and thirty-five women with DS, 31 to 67 years of age and nondemented at initial examination, were assessed for cognitive and functional abilities, behavioral/psychiatric conditions, and health status at 14-20 month intervals over five assessment cycles. We genotyped these individuals for single-nucleotide polymorphisms (SNPs) in CYP17 and CYP19. Four SNPs in CYP17 were associated with a two and one half-fold increased risk of AD, independent of APOE genotype. Four SNPs in CYP19 were associated with a two-fold increased risk of AD, although three were significant only in those without an APOE ε4 allele. Further, carrying high risk alleles in both CYP17 and CYP19 was associated with an almost four-fold increased risk of AD (OR = 3.8, 95% CI, 1.6-9.5) and elevated sex hormone binding globulin in postmenopausal women. The main effect of the CYP17 and CYP19 variants was to decrease the age at onset. These findings suggest that genes contributing to estrogen bioavailability influence risk of AD in women with DS.
    Journal of Alzheimer's disease: JAD 11/2011; 28(3):601-12. DOI:10.3233/JAD-2011-110860 · 3.61 Impact Factor
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    ABSTRACT: Triplication of chromosome 21 in Down syndrome (DS) results in overexpression of the minibrain kinase/dual-specificity tyrosine phosphorylated and regulated kinase 1A gene (DYRK1A). DYRK1A phosphorylates cytoplasmic tau protein and appears in intraneuronal neurofibrillary tangles (NFTs). We have previously shown significantly more DYRK1A-positive NFTs in DS brains than in sporadic Alzheimer disease (AD) brains. This study demonstrates a gene dosage-proportional increase in the level of DYRK1A in DS in the cytoplasm and the cell nucleus, and enhanced cytoplasmic and nuclear immunoreactivity of DYRK1A in DS. The results suggest that overexpressed DYRK1A may alter both phosphorylation of tau and alternative splicing factor (ASF). Two-dimensional electrophoresis revealed modification of ASF phosphorylation in DS/AD and AD in comparison to controls. Altered phosphorylation of ASF by overexpressed nuclear DYRK1A may contribute to the alternative splicing of the tau gene and an increase by 2.68 × of the 3R/4R ratio in DS/AD, and a several-fold increase in the number of 3R tau-positive NFTs in DS/AD subjects compared with that in sporadic AD subjects. These data support the hypothesis that phosphorylation of ASF by overexpressed DYRK1A may contribute to alternative splicing of exon 10, increased expression of 3R tau, and early onset of neurofibrillary degeneration in DS.
    Journal of Neuropathology and Experimental Neurology 01/2011; 70(1):36-50. DOI:10.1097/NEN.0b013e318202bfa1 · 4.37 Impact Factor
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    ABSTRACT: The primary abnormality in Down syndrome (DS), trisomy 21, is well known; but how this chromosomal gain produces the complex DS phenotype, including immune system defects, is not well understood. We profiled DNA methylation in total peripheral blood leukocytes (PBL) and T-lymphocytes from adults with DS and normal controls and found gene-specific abnormalities of CpG methylation in DS, with many of the differentially methylated genes having known or predicted roles in lymphocyte development and function. Validation of the microarray data by bisulfite sequencing and methylation-sensitive Pyrosequencing (MS-Pyroseq) confirmed strong differences in methylation (p<0.0001) for each of 8 genes tested: TMEM131, TCF7, CD3Z/CD247, SH3BP2, EIF4E, PLD6, SUMO3, and CPT1B, in DS versus control PBL. In addition, we validated differential methylation of NOD2/CARD15 by bisulfite sequencing in DS versus control T-cells. The differentially methylated genes were found on various autosomes, with no enrichment on chromosome 21. Differences in methylation were generally stable in a given individual, remained significant after adjusting for age, and were not due to altered cell counts. Some but not all of the differentially methylated genes showed different mean mRNA expression in DS versus control PBL; and the altered expression of 5 of these genes, TMEM131, TCF7, CD3Z, NOD2, and NPDC1, was recapitulated by exposing normal lymphocytes to the demethylating drug 5-aza-2'deoxycytidine (5aza-dC) plus mitogens. We conclude that altered gene-specific DNA methylation is a recurrent and functionally relevant downstream response to trisomy 21 in human cells.
    PLoS Genetics 11/2010; 6(11):e1001212. DOI:10.1371/journal.pgen.1001212 · 8.17 Impact Factor

Publication Stats

2k Citations
455.63 Total Impact Points

Institutions

  • 2006–2015
    • Kennedy Krieger Institute
      • Department of Behavioral Psychology
      Baltimore, Maryland, United States
  • 2008–2012
    • Johns Hopkins University
      • Department of Psychiatry and Behavioral Sciences
      Baltimore, Maryland, United States
  • 2010
    • National Institute of Child Health and Human Development
      Maryland, United States
  • 2007
    • Columbia University
      • Department of Epidemiology
      New York, New York, United States
  • 1983–2007
    • New York State Institute for Basic Research in Developmental Disabilities
      • Department of Psychology
      New York City, New York, United States
  • 2004
    • Kuopio University Hospital
      Kuopio, Northern Savo, Finland
  • 1997
    • Maastricht University
      • Department of Epidemiology
      Maestricht, Limburg, Netherlands