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To find associations of age, sex, and education with neuropsychological test performance in cognitively normal Spanish-speaking Costa Rican nonagenarians with little education; to provide norms; and to compare their performance with similar Puerto Ricans. For 95 Costa Ricans (90-102 years old, 0-6 years of education), multiple regression assessed associations with demographics of performance on six neuropsychological tests. Analyses of covariance compared them with 23 Puerto Ricans (90-99 years old). Younger age and being female-but not education-were associated with better performance on some neuropsychological tests, in particular episodic memory. The Puerto Ricans performed better on learning and memory tasks. In cognitively intact Spanish-speaking nonagenarians with little or no education, education did not affect test performance. Additional studies of the effect of education on cognitive performance are warranted in other samples with extremely low education or old age. National differences in performance highlight the importance of group-specific norms. [ABSTRACT FROM AUTHOR]

A substantial body of evidence from dozens of studies in many different countries suggests an excess number of individuals with schizophrenia are born in winter months. The presence of a seasonality effect in regions with year-round warm climate, however, has rarely been examined. The major purpose of this project was to better understand if the seasonality effect on schizophrenic births that has been reported in other, mostly cold regions of the Northern Hemisphere, also can be detected in a warm, tropical climate. We set out to study birth months as risk factors, quantifying the risk for being born with schizophrenia for every month of the winter season in terms of incidence rate ratios (IRRs) in the central region of Puerto Rico. We also analyzed climatic data in order to determine if there was any correlation between the rate of schizophrenic births (n=710) to births in the general population (n=101,248) and average rainfall and temperature for every month of the year in our period of study (January 1932–December 1967). Our results suggest that the risk of developing schizophrenia is 36.5% higher for people born in February than for people born in the other months of the year (95% C.I.=6.6–74.8%). We also found correlations between the rate of schizophrenic to control births for any given month, and rainfall 4 months earlier (r=0.66, p=0.010), and temperature 5 months earlier (r=0.64, p=0.013) that remained significant after correcting for multiple comparisons. [Copyright &y& Elsevier]

ADAMTS12 belongs to the family of metalloproteinases that mediate a communication between specific cell types and play a key role in the regulation of normal tissue development, remodeling, and degradation. Members of this family have been implicated in neurodegenerative and neuroinflammatory, as well as in muscular-skeletal, cardiovascular, respiratory and renal diseases, and cancer. Several metalloproteinases have been associated with schizophrenia. In our previous study of the pedigree from a genetic isolate of Spanish origin in Puerto Rico, we identified a schizophrenia susceptibility locus on chromosome 5p13 containing ADAMTS12. This gene, therefore, is not only a functional but also a positional candidate gene for susceptibility to the disorder. In order to examine possible involvement of ADAMTS12 in schizophrenia, we performed mutation analysis of the coding, 5'- and 3'-untranslated, and putative promoter regions of the gene in affected members of the pedigree and identified 18 sequence variants segregated with schizophrenia. We then tested these variants in 135 unrelated Puerto Rican schizophrenia patients of Spanish origin and 203 controls and identified the intronic variant rs256792 (P = 0.0035; OR = 1.59; 95% CI = 1.16-2.17) and the two-SNP haplotype rs256603-rs256792 (P = 0.0023; OR = 1.62; 95% CI = 1.19-2.21) associated with the disorder. The association remained significant after correction for multiple testing. Our data support the hypothesis that genetic variations in ADAMTS12 influence the risk of schizophrenia.

Background: The AMACR gene is located in the schizophrenia susceptibility locus on chromosome 5p13, previously identified in a large Puerto Rican pedigree of Spanish origin. The AMACR-encoded protein is an enzyme involved in the metabolism of branched-chain fatty and bile acids. The enzyme deficiency causes structural and functional brain changes, and disturbances in fatty acid and oxidative phosphorylation pathways observed in individuals with schizophrenia. Therefore, AMACR is both a positional and functional candidate gene for susceptibility to schizophrenia., Methods: The study had a two-step design: we performed mutation analysis of the coding and flanking regions of AMACR in affected members of the pedigree, and tested the detected sequence variants for association with schizophrenia in a Puerto Rican case-control sample (n=383) of Spanish descent., Results and Conclusion: We identified three missense variants segregating with the disorder in the family, rs2278008, rs2287939 and rs10941112. Two of them, rs2278008 and rs2287939, demonstrated significant differences in genotype (P = 4 × 10-4, P = 4 × 10-4) and allele (P = 1 × 10-4, P = 9.5 × 10-5) frequencies in unrelated male patients compare to controls, with the odds ratios (OR) 2.24 (95% CI: 1.48-3.40) and 2.25 (95% CI: 1.49-3.38), respectively. The G-C-G haplotype of rs2278008-rs2287939-rs10941112 revealed the most significant association with schizophrenia (P = 4.25 × 10-6, OR = 2.96; 95% CI: 1.85-4.76) in male subjects. There were no statistically significant differences in genotype, allele, and haplotype frequencies between female schizophrenia subjects and controls. Our results suggest that AMACR may play a significant role in susceptibility to schizophrenia in male patients., (Copyright © 2010 Elsevier B.V. All rights reserved.)

APOE epsilon4 is a major risk factor for Alzheimer's disease. It has also been associated with cognitive impairment and cognitive decline in young-olds, but the impact of the epsilon4 allele on cognitive function in very late life is still unclear. The object of this study was to evaluate the association of the epsilon4 allele of APOE with the cognitive performance of a sample of non-demented oldest-olds. Eighty-seven Spanish-speaking Puerto Rican non-demented nonagenarians were administered a complete neuropsychological assessment and provided a blood sample used for APOE genotyping. A factor analysis generated two factors: 1) verbal memory; and 2) visuo-spatial, naming and attention tasks, accounting for 43.6% of the overall variance in the 13 original neuropsychological variables. The multivariate analysis reflected, after controlling for gender, education, and age, the APOE epsilon4 carriers performed better in overall cognition (both factors analyzed together) than non-carriers (T;{2} = 0.082, F(2,80) = 3.289, p = 0.042). Neither gender nor the gender by APOE epsilon4 status interaction was associated with differences in cognition. In conclusion, the results of this study suggest that, among these Puerto Rican non-demented nonagenarians, being an APOE epsilon4 allele carrier is associated with better cognition.

Many studies have found that individuals with schizophrenia have been born in winter months in disproportionately high numbers. Temperature and weather effects, such as hot summers or cold winters, have been among the suggested explanations for this seasonality effect. We studied the relationship between schizophrenia and season of birth in Puerto Rico, a tropical island with mild seasonal variation of temperature and virtually no cold periods. Our sample consisted of 132 subjects (57 with schizophrenia, 75 without) from 24 multiplex families. Schizophrenic family members were significantly more likely to be born during the winter months (21/57; 36.8%) than their unaffected relatives (16/75; 21.3%). These results suggest that extreme temperatures are not a sufficient explanation for the seasonality effect and that other factors associated with seasonality may have an effect on the later development of schizophrenia. The fact that a seasonality effect was found in a group likely to have an increased genetic loading for schizophrenia suggests that seasonality may be associated with a second, environmental "hit" in a "two-hit hypothesis" of schizophrenia.

A locus involved in schizophrenia and related disorders in a Puerto Rican family has previously been mapped to chromosome 5p. The maximum two-point log of the odds (LOD) score of 3.72 was obtained for marker D5S111, and increased to 4.37 by multipoint analysis, assuming autosomal dominant inheritance with 90% penetrance. Additional genotyping and haplotype analysis placed the novel locus on 5p13.2-p13.3 within the interval between markers D5S1993 and D5S631. In the current study, we saturated the interval between markers D5S1993 and D5S631 with densely spaced polymorphic markers, genotyped these markers in the most informative branch of the family, and narrowed the critical region to 2.8 Mb. G-protein-coupled receptor gene [somatostatin and angiotensin-like peptide receptor (SALPR)] is one of the candidate genes within the critical interval. Sequence analysis of the coding region and the putative promoter of somatostatin and angiotensin-like peptide receptor did not reveal functionally significant variants in affected family members, although several polymorphisms were detected.