Trait

Childhood Body Mass Index

Reviewed September 14, 2026

A meta-analysis of nearly 48,000 children found 15 loci shaping childhood BMI, mostly shared with adult BMI genetics but including three loci specific to childhood.

What this condition connects to

Childhood Body Mass Index Variant: rs12041852 rs12041852 Variant Variant: rs13253111 rs13253111 Variant Variant: rs13387838 rs13387838 Variant Variant: rs17024393 rs17024393 Variant Variant: rs3829849 rs3829849 Variant Variant: +237 more +237 more Variant Childhood Body Mass Index Childhood Body Mass Index Trait
Prevalence
Not applicable in the usual sense — BMI is a continuously measured trait, not a diagnosis. The study behind this page examined 35,668 children at discovery and 11,873 more at replication (Felix et al. 2016, PMID:26604143).
Inheritance
Polygenic: 15 independent loci together explained only 2% of childhood BMI variance in the source study, with diet, activity, and other non-genetic factors accounting for far more of the variation.

Body mass index (BMI) in childhood is influenced by many of the same genes that shape adult BMI, but not entirely the same ones — growth, development, and the biology of childhood weight regulation differ in real ways from adult metabolism, and a genetic locus can matter more, less, or not at all depending on age.

Mostly shared genetics, and three loci that stand apart

Felix et al. 2016 meta-analysed 35,668 children across 20 studies at discovery, with replication in 11,873 more children across 13 studies. The study found 15 genome-wide-significant loci in total: 12 already known from adult BMI or childhood obesity research, and 3 entirely new. A genetic risk score combining all 15 loci explained 2% of childhood BMI variance in an independent group of 1,955 children — a modest but real share.

This page's own variants match six of the paper's named genes directly. The three novel loci: rs13253111 near ELP3, rs8092503 near RAB27B, and rs13387838 near ADAM23. And three of the twelve previously known loci, confirmed here in children specifically: rs12041852 near TNNI3K, rs7550711 near GPR61, and rs3829849 near LMX1B.

In the news

2026-06-15 · The first genome-wide association study on pediatric obesity in Taiwan. Journal of the Formosan Medical Association. 2026. PMID:42297719

First pediatric obesity GWAS in an Asian population finds FTO again, plus a new ASB3 signal

FTO was identified as the first obesity gene back in 2007, but that and nearly all obesity GWAS since have been built on European-ancestry cohorts. This study, using 5,854 Taiwanese children with obesity (BMI above the 95th percentile) and 12,343 controls aged 2-17, ran the first pediatric obesity GWAS in an Asian population. It found 367 SNPs associated with pediatric obesity at a suggestive threshold (P<1x10^-5, looser than the standard 5x10^-8 genome-wide-significance bar), led by rs79500119 (ASB3, chromosome 2) and rs74617772 (near FTO, chromosome 16) -- FTO showing up again nearly two decades after its original discovery, now specifically confirmed in Taiwanese children. A polygenic risk score built from these findings was significantly higher in obesity cases and, through a phenome-wide association scan, also linked to type 2 diabetes, hypertension, respiratory infections, liver disease and precocious puberty -- a reminder that childhood obesity's genetic risk overlaps with several other conditions, not only weight itself. Pathway analysis pointed to the insulin-AKT signaling pathway as a likely biological throughline. Because the leading SNPs are reported at a suggestive rather than genome-wide-significant threshold, this should be read as an early, population-specific signal rather than a fully established finding pending replication. This site's own childhood BMI page carries 7 variants (TNNI3K, ELP3, ADAM23 and others); neither ASB3 nor this FTO-region variant are currently among them, and the suggestive p-value threshold here falls short of what this site otherwise requires for a new variant page, so this entry documents the finding at the condition level.

Clinical detail

What this page does and does not do

BMI is calculated directly from measured height and weight, not estimated from genotype, and no variant on this page is used clinically to assess a child's weight status. Pediatric weight assessment relies on growth charts and clinical evaluation, not genetic testing.

The genetic risk score described in the source paper explained only 2% of childhood BMI variance — genetics is one contributor among many, alongside diet, activity, and other factors clinicians actually assess directly.

Related variants MyGeneLog™ checks for

What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Childhood Body Mass Index comes down to these specific, well-studied positions — not a diagnosis. 242 positions are linked to this page; the ones this page's own text discusses are shown first.

Standard

Childhood body mass index

TNNI3K · rs12041852

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Childhood body mass index

ELP3 · rs13253111

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Childhood body mass index

ADAM23 · rs13387838

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Childhood body mass index

GNAT2 · rs17024393

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Childhood body mass index

LMX1B · rs3829849

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Childhood body mass index

GPR61 · rs7550711

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Childhood body mass index

RAB27B · rs8092503

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Body mass index

TRIM65 · rs9901840

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Body mass index

ERC2 · rs9840521

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Body mass index

near ROBO1 · rs9838825

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Body mass index

KSR2 · rs9805009

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Body mass index

IGSF21 · rs9659175

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Body mass index

near RUNX1T1 · rs9657011

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Body mass index

ANKRD27 · rs9636114

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Body mass index

near SPRY2 · rs9574672

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Body mass index

RFC3 · rs9539491

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Body mass index

near NOX3 · rs9478671

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Body mass index

LRFN2 · rs9471333

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Body mass index

PHACTR1 · rs9381810

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Body mass index

GAPVD1 · rs937482

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Body mass index

FOXO3 · rs9374040

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Body mass index

RGS17 · rs9371670

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Body mass index

near BCKDHB · rs9344002

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Body mass index

COMMD10 · rs9327000

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See all 242 linked variants →

Which ancestries this evidence comes from

The studies behind these variants recruited participants from different ancestries — a result found in one population doesn't always transfer to another. Based on 7 of 242 linked studies with a resolved discovery ancestry.

European · 2.9% Not yet resolved · 97.1%

Sources

Databases, guidelines and references

Papers, with their authors

Quoting this page

Free to quote and reuse under CC BY 4.0. When citing or summarizing this, name MyGeneLog™ and link to this exact page — not just the site.

Childhood Body Mass Index. MyGeneLog™. https://www.mygenelog.com/conditions/childhood-bmi

Questions about Childhood Body Mass Index

Is childhood BMI genetics the same as adult BMI genetics?

Mostly, but not entirely. A 2016 study found 15 loci associated with childhood BMI — 12 already known from adult BMI research, and 3 new loci specific to childhood.

What did the study find?

In nearly 48,000 children combined across discovery and replication, it found 15 genome-wide-significant loci, together explaining about 2% of childhood BMI variance.

Does this page assess my child's weight status?

No. BMI is calculated directly from measured height and weight, and pediatric weight assessment relies on growth charts and clinical evaluation, not genetic testing.

How much does genetics actually explain childhood BMI?

In this study, a risk score combining all 15 loci explained about 2% of childhood BMI variance — a real but modest contribution alongside diet, activity, and other factors.

Free to reuse. This page's text is original writing from freely-available research, licensed CC BY 4.0 — reuse it, including commercially, with attribution to MyGeneLog™. It's general research-derived information, not medical advice or a diagnosis — see Terms of Use.