37 loci linked to gestational diabetes, 7 novel, in large multi-ancestry meta-analysis

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Nature communications Published June 3, 2026 Medically reviewed June 3, 2026 Study authors: Brito Nunes Caroline, Rukins Valentina, Cisse Aminata H, White Frédérique, McBride Nancy, Kuang Alan… PubMed ↗ DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Interpret these 37 GDM loci (7 novel) as evidence of both shared and pregnancy-specific genetic mechanisms, but await replication in diverse populations.

This meta-analysis of genome-wide association studies (GWAS) across multi-ancestry populations, including up to 38,305 GDM cases and 776,145 controls, identified 37 loci associated with gestational diabetes mellitus (GDM), of which 7 are novel. Five novel loci were also identified for pregnancy glycemic traits. The analysis classified 12 GDM variants with stronger effects in GDM than in type 2 diabetes mellitus (T2DM) into five biologically informed categories. Notably, four loci (G6PC2, CAST-PCSK1, HKDC1, FOXA2) lacked genome-wide-significant T2DM associations, suggesting pregnancy-specific effects. Distinct causal variants for GDM were found at GCK, and MTNR1B showed pregnancy-amplified effects. The authors note the need for larger, ancestrally diverse studies of GDM and glycemic traits during pregnancy to better understand potential pregnancy-specific effects. These findings underscore the genetic heterogeneity of GDM and its overlap with T2DM, while pointing to unique pregnancy-related pathways that may inform future risk prediction and therapeutic targets.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

PMID42225636

View Original Abstract ↓

Gestational diabetes mellitus (GDM) affects ~14% of pregnancies and increases maternal type 2 diabetes mellitus (T2DM) risk. The GenDiP Consortium presents trans-generational, multi-ancestry genome-wide association study meta-analyses of GDM and pregnancy glycemic traits in up to 38,305 GDM cases and 776,145 controls. We identify 37 GDM-associated loci (7 novel) and five novel loci for pregnancy glycemic traits, all operating through the maternal genome. We classify 12 GDM variants with stronger effects in GDM than T2DM into five biologically informed categories, revealing pleiotropy patterns, pregnancy-dependent effect modification, and diagnostic heterogeneity. While all these loci overlap with T2DM and/or non-pregnant glycaemic traits, four (G6PC2, CAST-PCSK1, HKDC1, FOXA2) lack genome-wide-significant T2DM associations; GCK shows distinct causal variants for GDM, and MTNR1B exhibits pregnancy-amplified effects. Our findings provide new genetic insights into GDM and highlight the need for larger, ancestrally diverse studies of GDM and glycaemic traits during pregnancy to understand potential pregnancy-specific effects.