Estimating heritability of height without zygosity information for twins under five years in low- and middle-income countries: An application of normal finite mixture distribution models

Omar Karlsson; Benjamin W Domingue; Rockli Kim; S V Subramanian

doi:10.1016/j.ssmph.2022.101043

Estimating heritability of height without zygosity information for twins under five years in low- and middle-income countries: An application of normal finite mixture distribution models

SSM Popul Health. 2022 Feb 9:17:101043. doi: 10.1016/j.ssmph.2022.101043. eCollection 2022 Mar.

Authors

Omar Karlsson^{1

2}, Benjamin W Domingue³, Rockli Kim^{4

5

6}, S V Subramanian^{6

7}

Affiliations

¹ Takemi Program in International Health, Harvard T.H. Chan School of Public Health, Harvard University, 677 Huntington Avenue, Boston, MA, 02115, United States.
² Department of Economic History, School of Economics and Management, Lund University, P.O. Box 7083, 220 07, Lund, Sweden.
³ Graduate School of Education, Stanford University, 520 Galvez Mall, Stanford, CA, 94305, USA.
⁴ Division of Health Policy & Management, College of Health Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea.
⁵ Interdisciplinary Program in Precision Public Health, Department of Public Health Sciences, Graduate School of Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea.
⁶ Harvard Center for Population and Development Studies, 9 Bow Street, Cambridge, MA, 02138, United States.
⁷ Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Harvard University, 677 Huntington Avenue, Boston, MA, 02115, United States.

Abstract

Twin studies are widely used to estimate heritability of traits and typically rely on knowing the zygosity of twin pairs in order to determine variation attributable to genetics. Most twin studies are conducted in high resource settings. Large scale household survey data, such as the Demographic and Health Surveys, collect various biomarkers for children under five years old in low- and middle-income countries. These data include twins but no information on zygosity. We applied mixture models to obtain heritability estimates without knowing zygosity of twins, using 249 Demographic and Health Surveys from 79 low- and middle-income countries (14,524 twin pairs). We focused on height of children, adjusted for age and sex, but also provided estimates for other biomarkers available in the data. We estimated that the heritability of height in our sample was 46%.

Keywords: Height; Heritability; Low- and middle-income countries; Twin studies; Unknown zygosity.