The second most common form of dementia, mapped by the largest genome-wide study of it to date — which confirmed GBA1 among four known risk genes and found one new one.
Dementia with Lewy bodies (DLB) is the second most prevalent form of dementia, marked by abnormal protein deposits (Lewy bodies) inside brain cells. Most of its genetic risk has stayed uncharacterized — this page covers the one variant on this site tied to a large-scale effort to change that.
A 2025 genome-wide association study in Molecular Psychiatry ran the largest DLB meta-analysis so far: 4,252 people with DLB and 189,290 controls. The study confirmed four previously known risk loci — APOE, GBA, BIN1, and SNCA-AS1 — and identified one new one, SYT16. rs2230288, in GBA1, is one of the four confirmed loci, not the newly discovered one; GBA's link to Lewy body dementia was already established before this study, which reaffirmed it at a larger scale.
The same study found that DLB is genetically correlated with both Alzheimer's disease and Parkinson's disease — consistent with clinical overlap already seen between these conditions, now shown at the level of shared genetic risk rather than just shared symptoms.
Positions joined since this page was written
What this is The text above discusses the variants this page was written around. Since then the catalogue has joined 1 more position to it, by shared trait or shared paper. They are listed here by the paper each came from; the text does not describe them, and each variant page carries that study's own record.
Mega Vascular Cognitive Impairment and Dementia (MEGAVCID) consortium 2024, Alzheimer's & dementia : the journal of the Alzheimer's Association rs3764650 (ABCA7) — PMID:39046104
Dementia with Lewy bodies is diagnosed clinically, through cognitive and neurological assessment plus imaging — not by genotype. This one variant is a piece of the disease's genetic architecture from a large research study, not a diagnostic marker.
GBA1 (the gene carrying this variant) also carries well-established risk variants for Parkinson's disease and Gaucher disease in other research — one more piece of the genetic overlap this same study found at the population level between DLB, Alzheimer's, and Parkinson's disease.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Dementia with Lewy Bodies comes down to these specific, well-studied positions — not a diagnosis.
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Dementia with Lewy Bodies. MyGeneLog™. https://www.mygenelog.com/conditions/dementia-with-lewy-bodies
Dementia with Lewy bodies (DLB) is the second most prevalent form of dementia, caused by abnormal protein deposits called Lewy bodies forming inside brain cells.
No. A 2025 genome-wide study confirmed GBA among four previously known risk loci (alongside APOE, BIN1, and SNCA-AS1) — the study’s one newly discovered locus was a different gene, SYT16.
Genetically, yes — the same 2025 study found DLB is significantly positively correlated with both Alzheimer’s disease and Parkinson’s disease at the genetic level.
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