Alzheimer Disease: Van Deerlin V

Brickell KL, Leverenz JB, Steinbart EJ, Rumbaugh M, Schellenberg GD, Nochlin D, Lampe TH, Holm IE, Van Deerlin V, Yuan W, Bird TD. · Neurological Foundation of New Zealand, New Zealand. · J Neurol Neurosurg Psychiatry. · Pubmed #17615170 No free full text.

Abstract: AIM: Neuropathological examination of both individuals in a monozygotic (MZ) twin pair with Alzheimer's disease (AD) is rare, especially in the molecular genetic era. We had the opportunity to assess the concordance and discordance of clinical presentation and neuropathology in three MZ twin pairs with AD. METHODS: The MZ twins were identified and characterised by the University of Washington Alzheimer's Disease Research Center. We reviewed the available clinical and neuropathological records for all six cases looking specifically for concordance and discordance of clinical phenotype, neuritic amyloid plaques (NP), neurofibrillary tangles (NFT) and Lewy related pathology (LRP). RESULTS: Discordance in age of onset for developing AD in the MZ twins varied from 4 to 18 years. Clinical presentations also differed between twins. One twin presented with a dementia with Lewy Body clinical syndrome while the other presented with typical clinical AD. Neuropathology within the MZ twin pairs was concordant for NP and NFT, regardless of duration of disease, and was discordant for LRP. This difference was most marked in the late onset AD twin pair. One pair was found to have a mutation in presenilin-1 (PS1) (A79V) with remarkably late onset in a family member. CONCLUSIONS: MZ twins with AD can vary considerably in age of onset, presentation and disease duration. The concordance of NP and NFT pathological change and the discordance of LRP support the concept that, in AD, the former are primarily under genetic control whereas the latter (LRP) is more influenced by disease duration and environmental factors. The A79V mutation in PS1 can be associated with very late onset of dementia.

Myers AJ, Pittman AM, Zhao AS, Rohrer K, Kaleem M, Marlowe L, Lees A, Leung D, McKeith IG, Perry RH, Morris CM, Trojanowski JQ, Clark C, Karlawish J, Arnold S, Forman MS, Van Deerlin V, de Silva R, Hardy J. · Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892-3707, USA. · Neurobiol Dis. · Pubmed #17174556 No free full text.

Abstract: Previously we have shown that the H1c haplotype on the background of the H1 clade of haplotypes at the MAPT locus is associated with increased risk for progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and Alzheimer's disease (AD). Here we replicated the association with AD in an additional autopsy confirmed series. We show that this haplotype increases both the expression of total MAPT transcript as well as specifically increasing the proportion of 4 microtubule binding repeat containing transcripts. We discuss these findings both in terms of the problems facing the dissection of the etiologies of complex traits and the pathogenesis of the tauopathies.

Brickell KL, Steinbart EJ, Rumbaugh M, Payami H, Schellenberg GD, Van Deerlin V, Yuan W, Bird TD. · Department of Neurology, VA Puget Sound Health Care System, University of Washington, 1660 S. Columbian Way, Seattle, WA 98108, USA. · Arch Neurol. · Pubmed #16966510 links to  free full text

Abstract: BACKGROUND: Genetic influences on the development of late-onset Alzheimer disease (LOAD) are heterogeneous and ill defined. OBJECTIVE: To determine the genetic risk factors for LOAD. DESIGN: We asked the following questions: (1) Does early-onset Alzheimer disease (EOAD) occur in families with predominantly LOAD? and (2) Does the apolipoprotein E (APOE) genotype explain the wide differences in onset age in LOAD families? SETTING: University of Washington Alzheimer Disease Research Center, Seattle. PARTICIPANTS: A total of 136 kindreds and a separate group of 29 affected parent-child pairs. MAIN OUTCOME MEASURES: We evaluated the kindreds with familial LOAD for the occurrence of EOAD and the affected parent-child pairs with a 20-year or more difference in the age at onset. RESULTS: In the 136 kindreds with LOAD, 104 had only late-onset cases (men, 36%), whereas 32 families (24%) had a combination of LOAD and EOAD cases. The 44 EOAD cases in these families accounted for 20% of cases of AD in the 32 families and 6% in all 136 families. The early-onset cases had a mean +/- SD onset age of 56.1 +/- 3.2 years (range, 45-59 years; men, 50%). Seven (28%) of 25 individuals with EOAD sampled did not have an APOE epsilon4 allele, and 2 of the earliest-onset cases were epsilon3/epsilon3. In 29 parent-child pairs with a 20-year or more difference in age at onset, 7 (35%) of the 20 children sampled did not have an APOE epsilon4 allele. CONCLUSIONS: Many LOAD families (approximately 25%) have at least 1 individual with EOAD, and in these individuals, the ratio of men to women is nearly 50%, suggesting a possible subtype of familial AD. The APOE genotype plays an important role in these early-onset cases, but at least one fourth of the risk must represent the influence of other genetic and/or environmental factors. These LOAD families with early-onset cases represent an important resource for investigation of these factors.

Forman MS, Farmer J, Johnson JK, Clark CM, Arnold SE, Coslett HB, Chatterjee A, Hurtig HI, Karlawish JH, Rosen HJ, Van Deerlin V, Lee VM, Miller BL, Trojanowski JQ, Grossman M. · Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA. · Ann Neurol. · Pubmed #16718704 links to  free full text

Abstract: OBJECTIVE: Frontotemporal lobar degeneration (FTLD) is characterized by impairments in social, behavioral, and/or language function, but postmortem studies indicate that multiple neuropathological entities lead to FTLD. This study assessed whether specific clinical features predict the underlying pathology. METHODS: A clinicopathological correlation was performed on 90 consecutive patients with a pathological diagnosis of frontotemporal dementia and was compared with an additional 24 cases accrued during the same time period with a clinical diagnosis of FTLD, but with pathology not typically associated with frontotemporal dementia. RESULTS: Postmortem examination showed multiple pathologies including tauopathies (46%), FTLD with ubiquitin-positive inclusions (29%), and Alzheimer's disease (17%). The pathological groups manifested some distinct demographic, clinical, and neuropsychological features, although these attributes showed only a statistical association with the underlying pathology. FTLD with ubiquitin-positive inclusions was more likely to present with both social and language dysfunction, and motor neuron disease was more likely to emerge in these patients. Tauopathies were more commonly associated with an extrapyramidal disorder. Alzheimer's disease was associated with relatively greater deficits in memory and executive function. INTERPRETATION: Clinical and neuropsychological features contribute to delineating the spectrum of pathology underlying a patient diagnosed with FTLD, but biomarkers are needed that, together with the clinical phenotype, can predict the underlying neuropathology.

Mott RT, Dickson DW, Trojanowski JQ, Zhukareva V, Lee VM, Forman M, Van Deerlin V, Ervin JF, Wang DS, Schmechel DE, Hulette CM. · Department of Pathology (Neuropathology), Duke University Medical Center, Durham, North Carolina 27710, USA. · J Neuropathol Exp Neurol. · Pubmed #15892300 No free full text.

Abstract: The frontotemporal dementias (FTDs) are a heterogeneous group of neurodegenerative disorders that are characterized clinically by dementia, personality changes, language impairment, and occasionally extrapyramidal movement disorders. Historically, the diagnosis and classification of FTDs has been fraught with difficulties, especially with regard to establishing a consensus on the neuropathologic diagnosis. Recently, an international group of scientists participated in a consensus conference to develop such neuropathologic criteria. They recommended a diagnostic classification scheme that incorporated a biochemical analysis of the insoluble tau isoform composition, as well as ubiquitin immunohistochemistry. The use and reliability of this classification system has yet to be examined. In this study, we evaluated 21 cases of FTD. Using traditional histochemical stains and tau protein and ubiquitin immunohistochemistry, we separated each case into one of the following categories: classic Pick disease (PiD; n = 7), corticobasal degeneration (CBD; n = 5), dementia lacking distinctive histopathologic features (DLDH; n = 4), progressive supranuclear palsy (PSP; n = 2), frontotemporal lobar degeneration with motor neuron disease or motor neuron disease-type inclusions (FTLD-MND/MNI; n = 2), and neurofibrillary tangle dementia (NFTD; n = 1). Additionally, we independently categorized each case by the insoluble tau isoform pattern, including 3R (n = 5), 4R (n = 7), 3R/4R (n = 3), and no insoluble tau (n = 6). As suggested by the proposed diagnostic scheme, we found that the insoluble tau isoform patterns correlated strongly with the independently derived histopathologic diagnoses (p < 0.001). The data show that cases containing predominantly 3R tau were classic PiD (100%). Cases with predominantly 4R tau were either CBD (71%) or PSP (29%). Cases with both 3R and 4R tau were either a combination of PiD and Alzheimer disease (67%) or NFTD (33%). Finally, cases with no insoluble tau were either DLDH (67%) or FTLD-MND/MNI (33%). To further characterize these cases, we also performed quantitative Western blots for soluble tau, APOE genotyping, and, in selected cases, tau gene sequencing. We show that soluble tau is reduced in DLDH and FTLD-MND/MNI and that APOE4 is overrepresented in PiD and DLDH. We also identified a new family with the R406W mutation and pathology consistent with NFTD. This study validates the recently proposed diagnostic criteria and forms a framework for further refinement of this classification scheme.

Grossman M, Farmer J, Leight S, Work M, Moore P, Van Deerlin V, Pratico D, Clark CM, Coslett HB, Chatterjee A, Gee J, Trojanowski JQ, Lee VM. · Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA. · Ann Neurol. · Pubmed #15852395 No free full text.

Abstract: We assessed cerebrospinal fluid (CSF) levels of tau and other biomarkers of neurodegenerative disease. CSF tau levels vary widely in reports of frontotemporal dementia (FTD). CSF samples were assayed for tau, amyloid beta1-42 (A1-42), and the isoprostane 8,12-iso-iPF2a-VI (iP) prospectively in 64 patients with FTD, retrospectively in 26 autopsied cases with FTD or Alzheimer's disease (AD), and in 13 healthy seniors. To validate our observations in vivo, we correlated CSF tau levels with cortical atrophy in 17 FTD patients using voxel-based morphometry analyses of high-resolution magnetic resonance imaging. CSF levels of tau, Abeta1-42, and iP differed significantly in FTD compared with AD. Individual patient analyses showed that 34% of FD patients had significantly low levels of CSF tau, although this was never seen in AD. A discriminant analysis based on CSF levels of tau, Abeta1-42, and iP was able to classify 88.5% of these patients in a manner that corresponds to their clinical or autopsy diagnosis. Magnetic resonance imaging studies showed that CSF tau levels correlate significantly with right frontal and left temporal cortical atrophy, brain regions known to be atrophic in patients with autopsy-proved FTD. We conclude that CSF tau levels are significantly reduced in many patients with FTD.