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1.  Familial Aggregation of Dementia With Lewy Bodies 
Archives of Neurology  2011;68(1):90-93.
Familial aggregation of dementia with Lewy bodies (DLB) remains unclear.
To determine the degree of family aggregation of DLB by comparing DLB risk between siblings of probands with clinically diagnosed DLB and siblings of probands with clinically diagnosed Alzheimer disease in a cohort of Caribbean Hispanic families and to explore the degree of aggregation of specific clinical manifestations (ie, cognitive fluctuations, visual hallucinations, and parkinsonism) in DLB.
Familial cohort study.
Academic research.
We separately compared risks of possible DLB, probable DLB, and clinical core features of DLB (cognitive fluctuations, visual hallucinations, and parkinsonism) between siblings of probands with clinically diagnosed DLB (n=344) and siblings of probands with clinically diagnosed Alzheimer disease (n=280) in 214 Caribbean Hispanic families with extended neurologic and neuropsychological assessment.
Main Outcome Measures
We applied general estimating equations to adjust for clustering within families. In these models, age and proband disease status were independent variables, and disease status of siblings was the measure of disease risk and the dependent variable.
Compared with siblings of probands having clinically diagnosed Alzheimer disease, siblings of probands having clinically diagnosed DLB had higher risks of probable DLB (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.04–5.04) and visual hallucinations (2.32; 1.16–4.64). They also had increased risks of possible DLB (OR, 1.51; 95% CI, 0.97–2.34) and cognitive fluctuations (1.55; 0.95–2.53).
Dementia with Lewy bodies and core features of DLB aggregate in families. Compared with siblings of probands having clinically diagnosed AD, siblings of probands having clinically diagnosed DLB are at increased risks of DLB and visual hallucinations. These findings are an important step in elucidating the genetic risk factors underlying DLB and in delineating DLB from other neurodegenerative diseases, such as Alzheimer disease.
PMCID: PMC3268781  PMID: 21220678
2.  Age-At-Onset Linkage Analysis in Caribbean Hispanics with Familial Late-Onset Alzheimer’s Disease 
Neurogenetics  2007;9(1):51-60.
The aim of the study was to identify chromosomal regions containing putative genetic variants influencing age-at-onset in familial late-onset Alzheimer’s disease. Data from a genome-wide scan that included genotyping of APOE was analyzed in 1,161 individuals from 209 families of Caribbean Hispanic ancestry with a mean age-at-onset of 73.3 years multiply affected by late-onset Alzheimer’s disease. Two-point and multipoint analyses were conducted using variance component methods from 376 microsatellite markers with an average inter-marker distance of 9.3 cM. Family-based test of association were also conducted for the same set of markers. Age-at-onset of symptoms among affected individuals was used as the quantitative trait. Our results showed that the presence of APOE-ε4 lowered the age-at-onset by three years. Using linkage analysis strategy, the highest LOD scores were obtained using a conservative definition of LOAD at 5q15 (LOD 3.1) 17q25.1 (LOD=2.94) and 14q32.12 (LOD=2.36) and 7q36.3 (LOD=2.29) in covariate adjusted models that included APOE-ε4. Both linkage and family-based association identified 17p13 as a candidate region. In addition, family-based association analysis showed markers at 12q13 (p=0.00002), 13q (p=0.00043) and 14q23 (p=0.00046) to be significantly associated with age at onset. The current study supports the hypothesis that there are additional genetic loci that could influence age-at-onset of late onset Alzheimer’s disease. The novel loci at 5q15, 17q25.1, 13q and 17p13, and the previously reported loci at 7q36.3, 12q13, 14q23 and 14q32 need further investigation.
PMCID: PMC2701253  PMID: 17940814
Alzheimer’s disease; age-at-onset; linkage analysis; family-based association analysis; APOE
3.  Further Examination of the Candidate Genes in Chromosome 12p13 Locus for Late-Onset Alzheimer Disease 
Neurogenetics  2008;9(2):127-138.
A broad region on chromosome 12p13 has been intensely investigated for novel genetic variants associated with Alzheimer disease (AD). We examined this region with 23 microsatellite markers using 124 North European (NE) families and 209 Caribbean Hispanic families with late-onset AD (FAD). Significant evidence for linkage was present in a 5 cM interval near 20 cM in both the NE FAD (LOD=3.5) and the Caribbean Hispanic FAD (LOD=2.2) datasets. We further investigated these families and an independent NE case-control dataset using 14 single nucleotide polymorphisms (SNPs). The initial screening of the region at ~20 cM in the NE case-control dataset revealed significant association between AD and seven SNPs in several genes, with the strongest result for rs2532500 in TAPBPL (p=0.006). For rs3741916 in GAPDH, the C allele, rather than the G allele as was observed by Li and colleagues (2004), was the risk allele. When the two family datasets were examined, none of the SNPs were significant in NE families, but two SNPs were associated with AD in Caribbean Hispanics: rs740850 in NCAPD2 (p=0.0097) and rs1060620 in GAPDH (p=0.042). In a separate analysis combining the Caribbean Hispanic families and NE cases and controls, rs740850 was significant after correcting for multiple testing (empirical p=0.0048). Subsequent haplotype analyses revealed that two haplotype sets -- haplotype C-A at SNPs 6-7 within NCAPD2 in Caribbean Hispanics, and haplotypes containing C-A-T at SNPs 8-10 within GAPDH in Caribbean Hispanic family and NE case-control datasets -- were associated with AD. Taken together, these SNPs may be in linkage disequilibrium with a pathogenic variant(s) on or near NCAPD2 and GAPDH.
PMCID: PMC2635895  PMID: 18340469
Alzheimer disease; GAPDH; NCAPD2; linkage; association
4.  Comparison of Clinical Manifestation in Familial Alzheimer's disease and Dementia with Lewy Bodies 
Archives of neurology  2008;65(12):1634-1639.
The clinical delineation of Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) remains unclear.
To compare the neuropsychological profiles of patients with clinically diagnosed Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD).
We first compared measures of memory, orientation, language, executive, visual perception and visual construction function between persons with DLB and AD in two Caribbean Hispanic cohorts, including a family dataset (DLB =89; AD: n=118) and an epidemiologic dataset (DLB: n=70; AD: n=157). DLB in the family sample was further divided into i) families with two or more affected family members (DLB), or ii) one affected family member (DLB). To determine whether observed differences in cognitive profiles were driven by heritable factors, we then repeated the analyses in the epidemiologic cohort excluding all familial cases. We applied general linear models adjusting for age, sex, education, disease duration, and APOE-ε4 genotype.
Persons with DLB were in both cohorts more severely impaired in orientation, visual construction and non verbal reasoning after controlling for potential confounders. Persons with 2 or more DLB cases per family had the most severe impairment in episodic and semantic memory, followed by those with one DLB case per family, then by those with AD. When familial AD and DLB cases were excluded from the analysis in the epidemiologic cohort, the differences between the AD and DLB groups persisted but were attenuated.
Compared to persons with AD, persons with DLB are more severely impaired in various cognitive domains, particularly orientation, visual perception and visual construction. The difference appears strong in familial rather than sporadic DLB. Whether this divergence in cognitive functions is caused by gene-gene or gene-environmental interactions remains unclear.
PMCID: PMC2633487  PMID: 19064751
5.  The Heritability of Abstract Reasoning in Caribbean Latinos with Familial Alzheimer Disease 
Alzheimer disease (AD) is under substantial genetic influence. To better understand the genetic influence on component phenotypes of AD, we estimated the heritability (h2) of abstract reasoning, and examined its relation with APOE-ε4.
We studied abstract reasoning in 1,116 individuals from 210 Caribbean Hispanic families with late onset AD, using the Similarities subtest scores from the Wechsler Adult Intelligence Scale. We computed h2, then performed analysis of variance to examine the effect of APOE-ε4.
Abstract reasoning was highly heritable (h2unadjusted=79.9%). After adjusting for covariates, the h2 was reduced to 32.6%, with education accounting for 40.8% of the variance. The APOE-ε4 allele had no effect.
Abstract reasoning was strongly influenced by genetic factors and education. Genes other than APOE contribute to the inheritance of abstract reasoning ability.
PMCID: PMC2630497  PMID: 17938569
heritability; abstract reasoning; Alzheimer disease; cognitive reserve; neuropsychology; APOE

Results 1-5 (5)