130: Genetics + CRISPR to Map Obesity and Fat Distribution

Baya NA et al., The American Journal of Human Genetics - This episode summarizes a multi-modal study that integrates exome sequencing in 402,375 UK Biobank participants with CRISPR knockdown in human white adipocytes to nominate genes and pathways that alter overall adiposity and fat distribution. Key terms: obesity, fat distribution, exome sequencing, CRISPR knockdown, adipocytes.

Study Highlights:
The authors performed rare-variant (MAF<1%) exome-wide association testing across nine obesity- and depot-specific fat traits in 402,375 European-ancestry UK Biobank participants, identifying 19 exome-wide significant genes and 50 additional genes at FDR≤1% (69 total). They prioritized 14 genes for CRISPR-Cas9 knockdown in a human white adipocyte cell line and measured lipid accumulation with BODIPY staining and high-content imaging. Knockdown of PPARG and SLTM significantly decreased lipid accumulation, while COL5A3 knockdown increased it; EXOC7 and TRIP10 had nominal increases. Integrating population genetics, allelic series, longitudinal age-of-onset, and transcriptomics highlighted candidate therapeutic avenues to modulate adiposity and fat distribution.

Conclusion:
Combining large-scale human genetic association with targeted functional screens in human adipocytes identifies high-confidence genes and mechanisms—such as adipogenesis regulation and extracellular matrix components—that can inform therapeutic strategies to alter body fat amount and distribution.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Combining evidence from human genetic and functional screens to identify pathways altering obesity and fat distribution

First author:
Baya NA

Journal:
The American Journal of Human Genetics

DOI:
10.1016/j.ajhg.2025.08.013

Reference:
Baya NA, SurErdem I, Venkatesh SS, et al.; Claussnitzer M, Palmer DS, Lindgren CM. Combining evidence from human genetic and functional screens to identify pathways altering obesity and fat distribution. The American Journal of Human Genetics. 2025;112:1–22. https://doi.org/10.1016/j.ajhg.2025.08.013

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

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Episode link: https://basebybase.com/episodes/combining-evidence-from-human-genetic-and-functional-screens-to-identify-pathways-altering-obesity-and-fat-distribution

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2025-09-07.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections describing UK Biobank exome sequencing and nine fat-trait phenotypes, identification of candidate genes, CRISPR-Cas9 functional validation in human white adipocytes, key gene findings (PPARG, SLTM, COL5A3), monotonic dose–response relationships, and obesity-age-onset analyses.
- transcript topics: UK Biobank exome sequencing design and nine fat-related traits; Rare-variant gene-level associations and PoPS integration; CRISPR-Cas9 knockdown in human white adipose tissue cells and BODIPY lipid readouts; Key genes PPARG, SLTM, COL5A3 and their lipid-accumulation effects; Monotonic allelic series and dose-response relationships; Longitudinal obesity age-of-onset analyses (MC4R, SLTM)

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- UK Biobank exome sequencing on ~402,375 European-ancestry individuals across nine obesity-related traits
- 69 genes significantly associated with fat distribution; 19 exome-wide significant; 50 additional at BH FDR ≤ 1%
- 14 genes selected for CRISPR-Cas9 knockdown in differentiated human white adipose tissue cells
- PPARG and SLTM knockdown decreased lipid accumulation; COL5A3 knockdown increased lipid accumulation
- Monotonic allelic series observed in 22 genes for ultra-rare variants
- SLTM loss-of-function variants associated with higher BMI in humans; SLTM knockdown decreased lipid accumulation in adipocytes

QC result: Pass.