. Author manuscript; available in PMC: 2021 Nov 30.

Published in final edited form as: Nat Genet. 2021 May 31;53(6):840–860. doi: 10.1038/s41588-021-00852-9

Table 1.

Glossary of terms - This study combined analyses of trait-associations across multiple correlated glycemic traits and across multiple ancestries, which has presented challenges in our ability to apply commonly used terms with clarity. For this reason, we define below terms often used in the field with variable meaning, as well as definitions of new terms used in this study.

Term	Definition
EA (Effect allele)	The effect allele was that defined by METAL based on trans-ancestry FG results and aligned such that the same allele was kept as the effect allele across all ancestries and traits, irrespective of its allele frequency or effect size for that particular ancestry and trait, in this way the effect allele is not necessarily the trait-increasing allele.
Single-ancestry lead variant	Variant with the smallest p-value amongst all with P < 5x10^-8, within a 1Mb region, based on analysis of a single trait in a single ancestry.
Single-ancestry index variants	Variants identified by GCTA analysis of each autosome, and that appear to exert conditionally distinct effects on a given trait in a given ancestry (P < 5x10^-8). As defined, these include the single-ancestry lead variants.
Trans-ancestry lead variant	Variant identified by trans-ethnic meta-analysis of a given trait that has the strongest association for that trait (log₁₀BF > 6, which is broadly equivalent to P < 5x10^-8) within a 1Mb region.
Single-ancestry locus	1Mb region centred on a single-ancestry lead variant which does not contain a lead variant identified in the trans-ancestry meta-analysis (i.e., does not contain a trans-ancestry lead variant).
Signal	Conditionally independent association between a trait and a set of variants in LD with each other and which is noted by the corresponding index variant.
Trans-ancestry locus	A genomic interval that contains trans-ancestry trait-specific lead variants, with/out additional single-ancestry index variants, for one or more traits. This region is defined by starting at the telomere of each chromosome and selecting the first single-ancestry index variant or trans-ancestry lead variant for any trait. If other trans-ancestry lead variants or single-ancestry index variants mapped within 500kb of the first signal, then they were merged into the same locus. This process was repeated until there were no more signals within 500kb of the previous variant. A 500kb interval was added to the beginning of the first signal, and the end of the last signal to establish the final boundary of the trans-ancestry locus (Extended Data Figure 2). As defined, a trans-ancestry locus may not have a single lead trans-ancestry variant, but may instead contain multiple trans-ancestry lead variants, one for each trait.