---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '21484'
abstract:
- lang: eng
  text: An individual's phenotype reflects a complex interplay of the direct effects
    of their DNA, epigenetic modifications of their DNA induced by their parents,
    and indirect effects of their parents' DNA. Here, we derive how the genetic variance
    within a population is changed under the influence of indirect maternal, paternal
    and parent-of-origin effects under random mating. We also consider indirect effects
    of a sibling, in particular how the genetic variance is altered when looking at
    the phenotypic difference between two siblings. The calculations are then extended
    to include assortative mating (AM), which alters the variance by inducing increased
    homozygosity and correlations within and across loci. AM likely leads to covariance
    of parental genetic effects, a measure of the similarity of parents in the indirect
    effects they have on their children. We propose that this assortment for parental
    characteristics, where biological parents create similar environments for their
    children, can create shared parental effects across traits and the appearance
    of cross-trait AM. Our theory shows how the resemblance among relatives increases
    under both AM, indirect and parent-of-origin effects. When our model is used to
    predict correlations among relatives in human height, we find that explaining
    the patterns observed in real data requires both indirect genetic effects and
    assortative mating. The degree to which direct, indirect and epigenetic effects
    shape the phenotypic variance of complex traits remains an open question that
    requires large-scale family data to be resolved.
acknowledgement: We thank members of the Medical Genomics group at ISTA for their
  comments, which improved this manuscript. This work was funded by an SNSF Eccellenza
  Grant to MRR (PCEGP3-181181), and by core funding from the Institute of Science
  and Technology Austria.
article_number: iyag042
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Ilse
  full_name: Krätschmer, Ilse
  id: 30d4014e-7753-11eb-b44b-db6d61112e73
  last_name: Krätschmer
  orcid: 0000-0002-5636-9259
- first_name: Matthew Richard
  full_name: Robinson, Matthew Richard
  id: E5D42276-F5DA-11E9-8E24-6303E6697425
  last_name: Robinson
  orcid: 0000-0001-8982-8813
citation:
  ama: Krätschmer I, Robinson MR. A quantitative genetic model for indirect genetic
    effects and genomic imprinting under random and assortative mating. <i>Genetics</i>.
    2026;232(4). doi:<a href="https://doi.org/10.1093/genetics/iyag042">10.1093/genetics/iyag042</a>
  apa: Krätschmer, I., &#38; Robinson, M. R. (2026). A quantitative genetic model
    for indirect genetic effects and genomic imprinting under random and assortative
    mating. <i>Genetics</i>. Oxford University Press. <a href="https://doi.org/10.1093/genetics/iyag042">https://doi.org/10.1093/genetics/iyag042</a>
  chicago: Krätschmer, Ilse, and Matthew Richard Robinson. “A Quantitative Genetic
    Model for Indirect Genetic Effects and Genomic Imprinting under Random and Assortative
    Mating.” <i>Genetics</i>. Oxford University Press, 2026. <a href="https://doi.org/10.1093/genetics/iyag042">https://doi.org/10.1093/genetics/iyag042</a>.
  ieee: I. Krätschmer and M. R. Robinson, “A quantitative genetic model for indirect
    genetic effects and genomic imprinting under random and assortative mating,” <i>Genetics</i>,
    vol. 232, no. 4. Oxford University Press, 2026.
  ista: Krätschmer I, Robinson MR. 2026. A quantitative genetic model for indirect
    genetic effects and genomic imprinting under random and assortative mating. Genetics.
    232(4), iyag042.
  mla: Krätschmer, Ilse, and Matthew Richard Robinson. “A Quantitative Genetic Model
    for Indirect Genetic Effects and Genomic Imprinting under Random and Assortative
    Mating.” <i>Genetics</i>, vol. 232, no. 4, iyag042, Oxford University Press, 2026,
    doi:<a href="https://doi.org/10.1093/genetics/iyag042">10.1093/genetics/iyag042</a>.
  short: I. Krätschmer, M.R. Robinson, Genetics 232 (2026).
corr_author: '1'
das_tickbox: '1'
dataavailabilitystatement: "The code used to simulate data can be found at https://github.\r\ncom/medical-genomics-group/familyMC.
  Simulations are based\r\non genotype data from 1000 Genomes Project downloaded from\r\nhttps://ftp.1000genomes.ebi.
  ac.uk/vol1/ftp/release/20130502/.\r\nSupplemental material available at GENETICS
  online."
date_created: 2026-03-23T15:02:54Z
date_published: 2026-04-01T00:00:00Z
date_updated: 2026-07-27T11:56:04Z
day: '01'
ddc:
- '570'
department:
- _id: MaRo
doi: 10.1093/genetics/iyag042
external_id:
  pmid:
  - '41677404'
file:
- access_level: open_access
  checksum: 926322c83b02522e96ab7a86e4011eec
  content_type: application/pdf
  creator: dernst
  date_created: 2026-07-27T11:54:00Z
  date_updated: 2026-07-27T11:54:00Z
  file_id: '22425'
  file_name: 2026_Genetics_Kraetschmer.pdf
  file_size: 734475
  relation: main_file
  success: 1
file_date_updated: 2026-07-27T11:54:00Z
fulldoi: https://doi.org/10.1093/genetics/iyag042
has_accepted_license: '1'
intvolume: '       232'
issue: '4'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
pmid: 1
publication: Genetics
publication_identifier:
  issn:
  - 1943-2631
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
related_material:
  link:
  - relation: software
    url: https://github.com/medical-genomics-group/familyMC
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: no
title: A quantitative genetic model for indirect genetic effects and genomic imprinting
  under random and assortative mating
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 232
year: '2026'
...