0022 Klotho Genetic Variants Mediate the Association Between Obstructive Sleep Apnea and Short Telomere Length

Introduction

The core features of obstructive sleep apnea (OSA) can potentially contribute to the acceleration of telomere shortening mechanisms. Among these factors, klotho reduction can contribute since it is associated with accelerated systemic inflammation and oxidative stress and has recently been associated with OSA. Also, decreased levels of klotho are implicated in the regulation of telomerase activity. Therefore, we aimed to evaluate the effect of common genetic variants (SNPs) on KLOTHO gene on the association between OSA and short telomere length.

Methods

As part of the Sao Paulo Epidemiologic Sleep Study cohort, 1,042 individuals answered questionnaires, underwent polysomnography and had blood collected for DNA extraction. OSA was defined according to AHI equal or greater than 15 events per hour. Leukocyte telomere length (LTL) was measured through qPCR and SNPs were genotyped by microarray.

Results

LTL was significantly shorter in OSA compared to controls in a severity-dependent manner (B=0.055, CI=0.007–0.102, p=0.02). Among the 43 SNPs analyzed, we observed that 4 SNPs (rs525014, rs7982726, rs685417 and rs9563124) significantly mediated the association between OSA and short LTL (B=0.046, df=1, p=0.005; B=0.044, df=1, p=0.007; B=0.045, df=1, p=0.006; B=0.044, df=1, p=0.007; respectively). Furthermore, this association was under an additive model since having one or two alleles of the alternative variants were significantly associated with shorter LTL.

Conclusion

We could conclude that klotho opens a new venue in OSA research and would be applicable to prevent the consequences of short telomeres in individuals with OSA.

Support

This work was supported by grants from AFIP, FAPESP and CAPES.

Inflammation, neurotrophism and oxidative stress and childhood psychopathology in a large community sample

OBJECTIVE

To investigate the association between peripheral biomarkers and child psychopathology in a large community sample.

METHOD

A total of 625 aged 6- to 13-year old subjects were recruited from a community school-based study. Psychopathology was assessed using the Child Behaviour Checklist (CBCL). Psychiatric diagnosis was evaluated using the Development and Well-Being Assessment. The following biomarkers were examined in peripheral blood: brain-derived neurotrophic factor, cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, IFN-g, and TNF-α), chemokines (eotaxin/CCL11, IP-10, MCP-1), cytokine receptors (sTNFR1 and sTNFR2), and the oxidative stress marker TBARS.

RESULTS

We found significant associations between sTNFR2, eotaxin/CCL11 and CBCL total score, as well as with specific dimensions of psychopathology. There were different patterns of association between these biomarkers and psychological and behavioural symptoms in children with and without a mental disorder. TBARS, IL-6 and MCP-1 were more specific to some clusters of symptoms in children with a psychiatric diagnosis.

CONCLUSION

Our data support the potential use of biomarkers, especially those involved in immune-inflammatory pathways, in investigating neurodevelopmental psychopathology. Their association with different dimensions of symptoms might be of useful when analyzing illness severity and clusters of symptoms within specific disorders.

Wide clinical variability in cat eye syndrome patients: four non-related patients and three patients from the same family

A small supernumerary marker chromosome (sSMC) derived from chromosome 22 is a relatively common cytogenetic finding. This sSMC typically results in tetrasomy for a chromosomal region that spans the chromosome 22p arm and the proximal 2 Mb of 22q11.21. Using classical cytogenetics, fluorescence in situ hybridization, multiplex ligation-dependent probe amplification, and array techniques, 7 patients with sSMCs derived from chromosome 22 were studied: 4 non-related and 3 from the same family (mother, daughter, and son). The sSMCs in all patients were dicentric and bisatellited chromosomes with breakpoints in the chromosome 22 low-copy repeat A region, resulting in cat eye syndrome (CES) due to chromosome 22 partial tetrasomy 22pter→q11.2 including the cat eye chromosome region. Although all subjects presented the same chromosomal abnormality, they showed a wide range of phenotypic differences, even in the 3 patients from the same family. There are no previous reports of CES occurring within 3 patients in the same family. Thus, the clinical and follow-up data presented here contribute to a better delineation of the phenotypes and outcomes of CES patients and will be useful for genetic counseling.