BRCA1 · rs1799949
Where this position leads
Condition: Age at Menarche
Strength of the evidence
Its strongest genetic-study result is p = 10−12, with 3 associations in the GWAS Catalog.
4: ClinVar disease-causing, reviewed by an expert panel or a guideline (3–4 stars). 3: ClinVar, several labs agreeing (2 stars), or a genetic study at p ≤ 10−50. 2: ClinVar from one lab (1 star), or p ≤ 10−20. 1: ClinVar submitted without criteria (0 stars), or genome-wide significance (p ≤ 5×10−8). The higher of the two counts. It says how solid the evidence is, not whether it matters for a particular person.
What the study found
Who was studied 67,029 Japanese ancestry women; replicated in 73,397 European ancestry women.
The effect Each copy of the G allele shifted the measure 0.152 year lower (95% confidence interval 0.099-0.205); p = 3 × 10−8.
How common The G allele had a frequency of about 66% in the people studied.
Where it sits Chromosome 17, band 17q21.31 — a synonymous change in BRCA1.
What ClinVar records
Classification
Benign for Breast-ovarian cancer, familial, susceptibility to, 1, Familial cancer of breast, Hereditary cancer-predisposing syndrome, Hereditary breast ovarian cancer syndrome, Pancreatic cancer, susceptibility to, 4 and 1 more; reviewed by expert panel (3 of 4 stars, 34 submitters), last evaluated 2015-01-12.
ClinVar record 125536 NM_007294.4(BRCA1):c.2082C>T (p.Ser694=)
Change history MyGeneLog™ keeps a copy of every weekly release from 2026-10-19 and compares them. This position's classification has not changed since.
What this is ClinVar's aggregate record for this position (as of its 2026-10-19 release), not a result about you. A classification describes the variant against the condition named, as laboratories submitted it. Whether a person carries this variant, and what that would mean for them, is a question for a clinical test and a genetic counsellor.
How common each version is
AG
A 30.6% · G 69.3%
A 31.2% · G 68.8%
A 32.0% · G 68.0%
A 43.5% · G 56.5%
A 31.6% · G 68.4%
A 33.7% · G 66.3%
A 30.1% · G 69.9%
The share of all copies of this position that are each version. Source: the population studies published in dbSNP (US NCBI); each row names its study.
rs1799949 is a single position in the genome, in or near the BRCA1 gene. Published research associates it with menarche (age at onset). A single variant does not decide an outcome — it shifts a probability, and for most common variants the shift is small.
On MyGeneLog this position is linked to Age at Menarche. The research behind each link, and its sources, are set out on that condition page.
No. Common variants like this one move a probability slightly and, on their own, rarely decide anything about one person. Nothing on this page is a diagnosis, and health decisions should be made with a clinician who can see your whole picture.
GWAS Catalog, Nat Commun 2018, PMID:29773799. Every variant on MyGeneLog comes from public primary sources and is published with its citation and the date it was checked.
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.
Menarche (age at onset) (rs1799949). MyGeneLog™. https://www.mygenelog.com/variants/rs1799949