Shape Differences of Brain Important For Individualized Precision Medicine Interview with:
Chun Chieh Fan
Ph.D student
USCD Cognitive Science and
Professor Anders M. Dale Ph.D
Department of Cognitive Science,
Multimodal Imaging Laboratory, Department of Radiology
University of California, San Diego School of Medicine
La Jolla, CA 92037

Medical Research: What is the background for this study? What are the main findings?

Response: The shape of human skull is closely associated with the ancestral background. Forensics uses it for determining ethnicity. Anthropologists use it to infer neuroanatomical change in human evolution. Yet it is unclear the inner content of skull, human brain, contains how much information about individual’s ancestry.

Our study found that different continental ancestries are associated with unique cortical folding patterns. Even for contemporary populations in modern day USA, a melting pot of ethnicities, cortical folding patterns are highly predictive of the percentage of each continental ancestry, as determined based on the person’s genotype. These shape differences between ancestral heritages are not necessarily related to brain function. It is highly possible that the shape differences are resulting from a random process accumulated along human history, without significant functional consequences.

Medical Research: What should clinicians and patients take away from your report?

Response: Our findings are particularly important for individualized, or “precision”, medicine. If a clinician wants to know where an individual patient’s brain size or shape measures fall relative to age- and sex-matched norms or growth charts, it is essential that these norms be based on individuals with similar ancestral background. Otherwise, the comparisons can be misleading, and confounded by irrelevant ancestry effects. Building on the approach described in the Current Biology paper, we believe it will be possible to calculate personalized norms or growth charts for a range of brain measures, incorporating genetic information from each individual patient, which may enable earlier, and more sensitive detection of brain pathology or abnormal development.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: One natural extension of the study will be to investigate the specific genes and gene variants involved in the shape differences among ethnic ancestry groups. This effort will be greatly facilitated by ongoing large, multi-site studies involving brain imaging and genotyping.

When combined with large biobanking, precision medicine, and health outcomes research initiatives, the “Big Data” approach described in the Current Biology paper may allow for creation of personalized risk scores, incorporating quantitative measures from brain imaging, genomic information, ethnicity, family history, and molecular biomarkers, with much greater diagnostic and prognostic utility than current approaches.


Modeling the 3D Geometry of the Cortical Surface with Genetic Ancestry

Fan, Chun Chieh et al. Chun Chieh Fan ,Hauke Bartsch,Andrew J. Schork,Chi-Hua Chen,Yunpeng Wang,Min-Tzu Lo,Timothy T. Brown,Joshua M. Kuperman,Donald J. Hagler Jr.,Nicholas J. Schork,Terry L. Jernigan,Anders M. Dale

the Pediatric Imaging, Neurocognition, and Genetics Study

Current Biology (Cell Press)



Chun Chieh Fan and, & Professor Anders M. Dale Ph.D (2015). Shape Differences of Brain Important For Individualized Precision Medicine