Toxoplasma gondii Serointensity and Seropositivity: Heritability and Household-Related Associations in the Old Order Amish

Allyson R. Duffy, Jeffrey R. O’Connell, Mary Pavlovich, Kathleen A. Ryan, Christopher A. Lowry, Melanie Daue, Uttam K. Raheja, Lisa A. Brenner, André O. Markon, Cecile M. Punzalan, Aline Dagdag, Dolores E. Hill, Toni I. Pollin, Andreas Seyfang, Maureen W. Groer, Braxton D. Mitchell and Teodor T. Postolache
Additional contact information
Allyson R. Duffy: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD 20201, USA
Jeffrey R. O’Connell: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Mary Pavlovich: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Kathleen A. Ryan: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Christopher A. Lowry: Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, CO 80045, USA
Melanie Daue: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Uttam K. Raheja: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD 20201, USA
Lisa A. Brenner: Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, CO 80045, USA
André O. Markon: US Food and Drug Administration, College Park, MD 20740, USA
Cecile M. Punzalan: US Food and Drug Administration, College Park, MD 20740, USA
Aline Dagdag: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD 20201, USA
Dolores E. Hill: US Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705, USA
Toni I. Pollin: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Andreas Seyfang: College of Medicine, University of South Florida, Tampa, FL 33612, USA
Maureen W. Groer: College of Nursing, University of South Florida, Tampa, FL 33612, USA
Braxton D. Mitchell: Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Teodor T. Postolache: Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, MD 20201, USA

IJERPH, 2019, vol. 16, issue 19, 1-9

Abstract: Toxoplasma gondii ( T. gondii ) is an intracellular parasite infecting one third of the world’s population. Latent T. gondii infection has been associated with mental illness, including schizophrenia and suicidal behavior. T. gondii IgG antibody titers were measured via ELISA. The heritability of T. gondii IgG was estimated using a mixed model that included fixed effects for age and sex and random kinship effect. Of 2017 Old Order Amish participants, 1098 had positive titers (54.4%). The heritability for T. gondii serointensity was estimated to be 0.22 ( p = 1.7 × 10 −8 and for seropositivity, it was estimated to be 0.28 ( p = 1.9 × 10 −5 ). Shared household environmental effects (i.e., household effects) were also determined. Household effects, modeled as a random variable, were assessed as the phenotypic covariance between any two individuals who had the same current address (i.e., contemporaneous household), and nuclear household (i.e., the phenotypic covariance between parents and children only, not other siblings or spouses). Household effects did not account for a significant proportion of variance in either T. gondii serointensity or T. gondii seropositivity. Our results suggest a significant familial aggregation of T. gondii serointensity and seropositivity with significant heritability. The shared household does not contribute significantly to family aggregation with T. gondii , suggesting that there are possible unmeasured non-household shared and non-shared environmental factors that may play a significant role. Furthermore, the small but significant heritability effects justify the exploration of genetic vulnerability to T. gondii exposure, infection, virulence, and neurotropism.

Keywords: environment; household; genetics; heritability; infection; mental illness; parasitic infection; Toxoplasma gondii (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2019
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1660-4601/16/19/3732/pdf (application/pdf)
https://www.mdpi.com/1660-4601/16/19/3732/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jijerp:v:16:y:2019:i:19:p:3732-:d:273340

Access Statistics for this article

IJERPH is currently edited by Ms. Jenna Liu

More articles in IJERPH from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().