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Kemal Yaylali e76ae847a1 fix(science): stop scoring evidence that was never looked up
A review of the ranking's arithmetic found four things wrong, all of which
made the score look better informed than it was. Measurements below are from
this repo, not estimates.

**Components now abstain instead of inventing a number.** A run without a VEP
cache returns no allele frequencies, and rarity_score(None) read that as
"absent from gnomAD, therefore maximally rare" and awarded every variant a
free 0.25. jobs.has_frequencies / has_effect_scores record what the run
actually produced, absent components are dropped from the weighted mean, and
the remaining weights are renormalised so the score keeps its meaning. The UI
shows "not looked up" rather than a bar, and the funnel stops calling a step
"rare" when nothing was filtered.

**Allele frequency is no longer a model feature.** It dominated: the same
missense variant scored 0.887 at AF 0 and 0.0003 at AF 0.01. That double-
counted, because the ranking already scores frequency explicitly, putting
~45% of every rank on one measurement; and it was circular, because ACMG
assigns ClinVar's benign labels using frequency (BA1/BS1). Retraining without
it moves missense AUROC from 0.872 to 0.500 — exactly random. The old figure
was allele frequency, not variant-effect knowledge. The model therefore
abstains unless CADD or AlphaMissense is present, since otherwise it only
restates the consequence class.

**Phenotype matching is weighted by information content** and HPO annotations
are propagated up the ontology. Counting terms alike let "global
developmental delay" (IC 0.93) count as much as "dilated left subclavian
artery" (IC 7.88).

**A real bug in the propagation, found by checking it.** The ancestor walk
read a pre-order DFS backwards, which on a DAG lets a term resolve before one
of its parents and inherit that parent alone instead of its lineage. It
dropped 399 terms out of the phenotype branch, Camptodactyly and Chiari
malformation among them. Now a true post-order, tested against a reference
transitive closure.

The ontology arithmetic moved to rarelens_ml.hpo so it is covered by tests,
and rarelens_ml.benchmark measures the whole thing: across 10,178 published
cases the causal gene ranks first 45.9-81.0% of the time against 5,269 genes,
versus 0.02% for chance. docs/data.md reports that with its contamination
(HPO's annotations come from these same case reports), and includes the
measurement showing information-content weighting earns its place while
propagation does not - kept anyway, for a reason the docs argue rather than
assume.
2026-09-12 11:32:46 +01:00

106 lines
3.8 KiB
Python

import uuid
import numpy as np
import pandas as pd
import pytest
from factories import seed_case
from httpx import AsyncClient
from sqlalchemy import select
from app.db import SessionLocal
from app.models import JobStatus, Prediction, Variant
from app.services import scoring
def variant(**kw: object) -> Variant:
fields: dict = {"chrom": "22", "pos": 1, "ref": "A", "alt": "G", "annotations": {}}
fields.update(kw)
return Variant(**fields)
def test_raw_frame_sends_the_model_contract_columns() -> None:
frame = scoring.raw_frame([
variant(impact="HIGH", consequence="stop_gained", gnomad_af=None,
annotations={"CADD_PHRED": "35", "am_pathogenicity": "0.98"}),
variant(impact="LOW", consequence="synonymous_variant", gnomad_af=0.2, annotations={}),
])
assert list(frame.columns) == scoring.RAW_COLUMNS
assert frame["impact"].tolist() == ["HIGH", "LOW"]
assert frame["cadd_phred"].iloc[0] == "35"
assert pd.isna(frame["cadd_phred"].iloc[1])
# Frequency is scored by the ranking, auditably; sending it here too counted it twice.
assert "gnomad_af" not in frame.columns
class FakeModel:
def __init__(self, score: float) -> None:
self.score = score
def predict(self, frame: pd.DataFrame) -> np.ndarray:
assert list(frame.columns) == scoring.RAW_COLUMNS
return np.full(len(frame), self.score)
async def make_case(status: JobStatus, n_variants: int) -> tuple[uuid.UUID, uuid.UUID]:
return await seed_case(
status=status,
variants=[{"pos": i + 1, "annotations": {}} for i in range(n_variants)],
)
async def predictions(job_id: uuid.UUID) -> list[Prediction]:
async with SessionLocal() as s:
rows = await s.scalars(select(Prediction).join(Variant).where(Variant.job_id == job_id))
return list(rows)
@pytest.mark.usefixtures("db")
async def test_scoring_twice_updates_instead_of_failing(
client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
case_id, job_id = await make_case(JobStatus.succeeded, n_variants=3)
monkeypatch.setattr(scoring, "load_model", lambda: (FakeModel(0.9), "7"))
r = await client.post(f"/api/cases/{case_id}/score")
assert r.status_code == 200, r.text
assert r.json() == {"case_id": str(case_id), "scored": 3, "model_version": "7"}
monkeypatch.setattr(scoring, "load_model", lambda: (FakeModel(0.2), "8"))
r = await client.post(f"/api/cases/{case_id}/score")
assert r.status_code == 200, r.text
preds = await predictions(job_id)
assert len(preds) == 3
assert {(p.score, p.model_version) for p in preds} == {(0.2, "8")}
@pytest.mark.usefixtures("db")
async def test_scoring_an_unknown_case_is_404(client: AsyncClient) -> None:
r = await client.post(f"/api/cases/{uuid.uuid4()}/score")
assert r.status_code == 404
@pytest.mark.usefixtures("db")
async def test_scoring_before_the_annotation_finishes_is_409(client: AsyncClient) -> None:
case_id, _ = await make_case(JobStatus.running, n_variants=1)
r = await client.post(f"/api/cases/{case_id}/score")
assert r.status_code == 409
@pytest.mark.usefixtures("db")
async def test_an_unreachable_model_registry_is_explained_not_a_500(
client: AsyncClient, monkeypatch: pytest.MonkeyPatch
) -> None:
case_id, _ = await make_case(JobStatus.succeeded, n_variants=1)
def unreachable() -> tuple:
raise ConnectionError("connection refused to http://localhost:5000")
monkeypatch.setattr(scoring, "load_model", unreachable)
r = await client.post(f"/api/cases/{case_id}/score")
assert r.status_code == 503
detail = r.json()["detail"]
# Names what is missing; the exception itself belongs in the server log, not the UI.
assert "rarelens-pathogenicity@production" in detail
assert "Max retries" not in detail and "Traceback" not in detail