The association of low socioeconomic status and the risk of having a child with Down syndrome: a report from the National Down Syndrome Project

• Authors: Jessica Ezzell Hunter, Emory University; Emily Allen, Emory University; Mikyong Shin, Centers for Disease Control and Prevention; Lora Bean, Emory University; Adolfo Correa, Emory University; Charlotte Druschel, New York State Department of Health; Charlotte A. Hobbs, University of Arkansas Medical Sciences; Leslie A. O'Leary, Centers for Disease Control and Prevention; Paul A. Romitti, University of Iowa; Marjorie H. Royle, New Jersey Department of Health and Senior Services; Claudine P. Torfs, Public Health Institute Oakland; Sallie Freeman, Emory University; Stephanie Sherman, Emory University
• Journal Title: GENETICS IN MEDICINE
• Volume: Volume 15, Number 9
• Publisher: NATURE PUBLISHING GROUP | 2013-09-01, Pages 698-705
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1038/gim.2013.34
• Subjects: Biology, Genetics; Economics, General; Sociology, Individual and Family Studies
• Keywords: Science & Technology; Life Sciences & Biomedicine; Genetics & Heredity; chromosome nondisjunction; Down syndrome; risk factors; socioeconomic status; trisomy 21; MATERNAL AGE; MEIOTIC STAGE; CHROMOSOME-21 NONDISJUNCTION; DNA HYPOMETHYLATION; PARENTAL ORIGIN; HUMAN OOCYTES; MEIOSIS-I; TRISOMY-21; RECOMBINATION; ETIOLOGY

Abstract

Purpose: Advanced maternal age and altered recombination are known risk factors for Down syndrome cases due to maternal nondisjunction of chromosome 21, whereas the impact of other environmental and genetic factors is unclear. The aim of this study was to investigate an association between low maternal socioeconomic status and chromosome 21 nondisjunction. Methods: Data from 714 case and 977 control families were used to assess chromosome 21 meiosis I and meiosis II nondisjunction errors in the presence of three low socioeconomic status factors: (i) both parents had not completed high school, (ii) both maternal grandparents had not completed high school, and (iii) an annual household income of <$25,000. We applied logistic regression models and adjusted for covariates, including maternal age and race/ethnicity. Results: As compared with mothers of controls (n = 977), mothers with meiosis II chromosome 21 nondisjunction (n = 182) were more likely to have a history of one low socioeconomic status factor (odds ratio = 1.81; 95% confidence interval = 1.07-3.05) and ≥2 low socioeconomic status factors (odds ratio = 2.17; 95% confidence interval = 1.02-4.63). This association was driven primarily by having a low household income (odds ratio = 1.79; 95% confidence interval = 1.14-2.73). The same statistically significant association was not detected among maternal meiosis I errors (odds ratio = 1.31; 95% confidence interval = 0.81-2.10), in spite of having a larger sample size (n = 532). Conclusion: We detected a significant association between low maternal socioeconomic status and meiosis II chromosome 21 nondisjunction. Further studies are warranted to explore which aspects of low maternal socioeconomic status, such as environmental exposures or poor nutrition, may account for these results.