Sander Lamballais

Postdoctoral Researcher

Clinical Genetics, Erasmus MC


Hi, my name is Sander Lamballais.

I am a postdoctoral researcher at the Erasmus MC, Netherlands.


My research focuses on two primary areas:

1. Methodology of genetics and genomics:

  • We create and study methods to explore complex genetics, with an emphasis on pleiotropy, polygenic scores, omics, and ancestry.
  • We develop and study methods for clinical cell-free DNA analysis, including methods for non-invasive prenatal testing (NIPT).

2. Genetic origins of health and disease:

Cross-trait associations

  • Challenge: Many unexpected observations in medicine remain unexplained. For example, the association between autism spectrum disorder (ASD) and gastrointestinal conditions is difficult to study due to their combined low prevalence and the absence of a clear biological framework.
  • Approach: By testing cross-trait associations across genome-wide association studies (GWASs) of different traits (e.g., ASD and gastrointestinal conditions), we can uncover potential genetic pathways that may explain these associations. Cross-analysis with gene expression and other omics datasets also offers insight into the spatial and temporal specificity of these mechanisms.

Polygenic scores

  • Challenge: The onset of disease etiology often predates the onset of symptoms. Exploring these presymptomatic stages can require large cohorts with years of follow-up in individuals who are not sick, which is simply not a feasible goal for most research questions.
  • Approach: We calculate polygenic scores for individuals, to estimate the genetic burden for diseases that are not (yet) present. This enables us to gain insight into disease etiology without the need for longer and extensive follow-up. For example, by estimating polygenic scores for schizophrenia in a pediatric cohort, we gain insight into how genetic burden for schizophrenia affects early brain development.

Non-invasive prenatal testing (NIPT)

  • Challenge: NIPT, a method for detecting cell-free DNA fragments from the placenta in the blood of a pregnant woman, is typically used to identify chromosomal aberrations like Down Syndrome, resulting from an extra copy of chromosome 21 (trisomy 21). However, current methods are mostly limited to reliable detection of trisomies, even though numerous other chromosomal aberrations exist.
  • Approach: Leveraging advanced statistical methodologies, we are developing innovative approaches that expand the detection capacity of NIPT to previously undetectable or unreliably detected chromosomal aberrations.


Examples of past projects

  • I am the lead developer of QDECR, an R package to perform vertex-wise analyses.
  • I co-designed and conducted the ORACLE Study, a cohort of 2,000 individuals with neuroimaging, cognitive testing, and more. I trained and led a team of over 20 BSc, MSc, and PhD students.
  • I wrote my doctoral thesis on how the brain takes shape across a lifetime.


Feel free to reach out if you:

  • Want to collaborate
  • Need a peer reviewer
  • Want to learn more about genetics or neuroimaging
  • Have questions about my work

Other noteworthy achievements

  1. I have beaten the Password Game [spoiler]. Good luck.


  • Methodology
  • Genetics & omics
  • Neuroimaging
  • Epidemiology


  • PhD in Neuroepidemiology, 2022

    Erasmus MC, NL

  • MSc in Genetic Epidemiology, 2015

    Erasmus MC, NL

  • MSc in Neuroscience, 2014

    Erasmus MC, NL

  • BSc in Psychology, 2012

    Erasmus University Rotterdam, NL

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