Lipids · LIVE

North American Familial Chylomicronemia Score (NAFCS)

NAFCS

Sum Hegele 2025 Table 3 NAFCS item points (age or early HTG onset, BMI, abdominal pain or pancreatitis, secondary factors, fasting TG, TG/TC ratio, apo B, and three published interactions) and return the 0–100 score plus ≥60 definite classical FCS and ≥45 very likely classical FCS flags. Not a diagnosis or genetic test.

LIVE $0.005 USDC GET /api/calc/nafcs

Markdown: /docs/nafcs.md · Canonical: https://magentlab.com/docs/nafcs

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Sum Hegele 2025 Table 3 NAFCS item points (age or early HTG onset, BMI, abdominal pain or pancreatitis, secondary factors, fasting TG, TG/TC ratio, apo B, and three published interactions) and return the 0–100 score plus ≥60 definite classical FCS and ≥45 very likely classical FCS flags. Not a diagnosis or genetic test.

When to use

When an agent already has caller-assigned Hegele 2025 NAFCS clinical flags and fasting TG, TG/TC ratio, and apo B in published units and needs the published point total. magent does not examine the patient, assay lipids, sequence genes, or apply Simon Broome or Dutch Lipid Clinic Network FH criteria.

When not to use

• Not a medical device and not a diagnosis of familial chylomicronemia syndrome or multifactorial chylomicronemia syndrome.
• magent does not examine the patient, assay lipids, or sequence genes. The caller assigns age, onset, BMI vs threshold, abdominal history, secondary factors, and labs.
• Not a genetic test. Not Simon Broome. Not Dutch Lipid Clinic Network FH. Not the European Moulin FCS score.
• The paper does not provide a score for infants under 1 year or for pregnancy. For age ≥10 the score assumes non-response to fibrates and high-dose omega-3 fatty acids (TG decrease <20%).
• A single fasting TG and TG/TC ratio stand in for Table 1 lab categories; all adult last-3 or child last-2 readings must meet the band as assigned by the caller.

Formula

NAFCS = early_htg_onset 12 (age_years ≥10 and htg_onset_before_age_10) + child_htg 12 (age_years 1-9) + all_tg_severely_elevated 13 (all fasting TG >880 mg/dL or >10 mmol/L) + high_tg_tc_ratio 8 (TG/TC >8 mg/dL or >3.5 mmol/L) + low_apo_b 12 (apo B <1.0 g/L or <100 mg/dL) + bmi_below_threshold 9 (BMI <25 kg/m2 or <85th percentile) + abdominal_pain 9 (recurrent abdominal pain without pancreatitis) + pancreatitis 16 + no_secondary_factors 11 + high_ratio_and_low_apo_b 7 + child_and_no_secondary 7 + high_ratio_and_no_secondary 5 (Hegele 2025 Table 3, parameter estimates ×10); max 100; ≥60 definite classical FCS; ≥45 very likely classical FCS

Citation

Title

Development and validation of clinical criteria to identify familial chylomicronemia syndrome (FCS) in North America

Authors

Hegele RA, Ahmad Z, Ashraf A, et al.

Source

J Clin Lipidol. 2025;19(1):83-94

DOI

10.1016/j.jacl.2024.09.008

Worked example

Also searched as

• North American Familial Chylomicronemia Score
• NAFCS Score
• North American FCS Score
• familial chylomicronemia syndrome score
• Hegele FCS score
• classical FCS clinical criteria
• NAFCS
• familial chylomicronemia criteria

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/nafcs?age_years=40&htg_onset_before_age_10=false&bmi_below_threshold=false&abdominal_history=none&secondary_factors_present=true&tg_mg_dl=500&tg_tc_ratio_mg_dl=5&apo_b_g_l=1.2

Full URL: https://api.magentlab.com/api/calc/nafcs?age_years=40&htg_onset_before_age_10=false&bmi_below_threshold=false&abdominal_history=none&secondary_factors_present=true&tg_mg_dl=500&tg_tc_ratio_mg_dl=5&apo_b_g_l=1.2

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/nafcs?age_years=40&htg_onset_before_age_10=false&bmi_below_threshold=false&abdominal_history=none&secondary_factors_present=true&tg_mg_dl=500&tg_tc_ratio_mg_dl=5&apo_b_g_l=1.2"

Parameters

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/nafcs Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "abdominal_history": "none",
      "age_years": "40",
      "apo_b_g_l": "1.2",
      "bmi_below_threshold": "false",
      "htg_onset_before_age_10": "false",
      "secondary_factors_present": "true",
      "tg_mg_dl": "500",
      "tg_tc_ratio_mg_dl": "5"
    },
    {
      "abdominal_history": "none",
      "age_years": "40",
      "apo_b_g_l": "1.2",
      "bmi_below_threshold": "false",
      "htg_onset_before_age_10": "false",
      "secondary_factors_present": "true",
      "tg_mg_dl": "500",
      "tg_tc_ratio_mg_dl": "5"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/nafcs",
  "items": [
    {
      "components": [
        {
          "factor": "early_htg_onset",
          "points": 0,
          "present": false
        },
        {
          "factor": "child_htg",
          "points": 0,
          "present": false
        },
        {
          "factor": "all_tg_severely_elevated",
          "points": 0,
          "present": false
        },
        {
          "factor": "high_tg_tc_ratio",
          "points": 0,
          "present": false
        },
        {
          "factor": "low_apo_b",
          "points": 0,
          "present": false
        },
        {
          "factor": "bmi_below_threshold",
          "points": 0,
          "present": false
        },
        {
          "factor": "abdominal_pain",
          "points": 0,
          "present": false
        },
        {
          "factor": "pancreatitis",
          "points": 0,
          "present": false
        },
        {
          "factor": "no_secondary_factors",
          "points": 0,
          "present": false
        },
        {
          "factor": "high_ratio_and_low_apo_b",
          "points": 0,
          "present": false
        },
        {
          "factor": "child_and_no_secondary",
          "points": 0,
          "present": false
        },
        {
          "factor": "high_ratio_and_no_secondary",
          "points": 0,
          "present": false
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "age_years": 40,
      "citation": {
        "authors": "Hegele RA, Ahmad Z, Ashraf A, et al.",
        "doi": "10.1016/j.jacl.2024.09.008",
        "id": "hegele-2025",
        "pmid": "39537503",
        "source": "J Clin Lipidol. 2025;19(1):83-94",
        "title": "Development and validation of clinical criteria to identify familial chylomicronemia syndrome (FCS) in North America"
      },
      "formula": "nafcs",
      "formula_expression": "NAFCS = early_htg_onset 12 (age_years ≥10 and htg_onset_before_age_10) + child_htg 12 (age_years 1-9) + all_tg_severely_elevated 13 (all fasting TG >880 mg/dL or >10 mmol/L) + high_tg_tc_ratio 8 (TG/TC >8 mg/dL or >3.5 mmol/L) + low_apo_b 12 (apo B <1.0 g/L or <100 mg/dL) + bmi_below_threshold 9 (BMI <25 kg/m2 or <85th percentile) + abdominal_pain 9 (recurrent abdominal pain without pancreatitis) + pancreatitis 16 + no_secondary_factors 11 + high_ratio_and_low_apo_b 7 + child_and_no_secondary 7 + high_ratio_and_no_secondary 5 (Hegele 2025 Table 3, parameter estimates ×10); max 100; ≥60 definite classical FCS; ≥45 very likely classical FCS",
      "max_score": 100,
      "score": 0,
      "all_tg_severely_elevated": false,
      "definite_classical_fcs": false,
      "high_tg_tc_ratio": false,
      "low_apo_b": false,
      "very_likely_classical_fcs": false
    },
    {
      "components": [
        {
          "factor": "early_htg_onset",
          "points": 0,
          "present": false
        },
        {
          "factor": "child_htg",
          "points": 0,
          "present": false
        },
        {
          "factor": "all_tg_severely_elevated",
          "points": 0,
          "present": false
        },
        {
          "factor": "high_tg_tc_ratio",
          "points": 0,
          "present": false
        },
        {
          "factor": "low_apo_b",
          "points": 0,
          "present": false
        },
        {
          "factor": "bmi_below_threshold",
          "points": 0,
          "present": false
        },
        {
          "factor": "abdominal_pain",
          "points": 0,
          "present": false
        },
        {
          "factor": "pancreatitis",
          "points": 0,
          "present": false
        },
        {
          "factor": "no_secondary_factors",
          "points": 0,
          "present": false
        },
        {
          "factor": "high_ratio_and_low_apo_b",
          "points": 0,
          "present": false
        },
        {
          "factor": "child_and_no_secondary",
          "points": 0,
          "present": false
        },
        {
          "factor": "high_ratio_and_no_secondary",
          "points": 0,
          "present": false
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "age_years": 40,
      "citation": {
        "authors": "Hegele RA, Ahmad Z, Ashraf A, et al.",
        "doi": "10.1016/j.jacl.2024.09.008",
        "id": "hegele-2025",
        "pmid": "39537503",
        "source": "J Clin Lipidol. 2025;19(1):83-94",
        "title": "Development and validation of clinical criteria to identify familial chylomicronemia syndrome (FCS) in North America"
      },
      "formula": "nafcs",
      "formula_expression": "NAFCS = early_htg_onset 12 (age_years ≥10 and htg_onset_before_age_10) + child_htg 12 (age_years 1-9) + all_tg_severely_elevated 13 (all fasting TG >880 mg/dL or >10 mmol/L) + high_tg_tc_ratio 8 (TG/TC >8 mg/dL or >3.5 mmol/L) + low_apo_b 12 (apo B <1.0 g/L or <100 mg/dL) + bmi_below_threshold 9 (BMI <25 kg/m2 or <85th percentile) + abdominal_pain 9 (recurrent abdominal pain without pancreatitis) + pancreatitis 16 + no_secondary_factors 11 + high_ratio_and_low_apo_b 7 + child_and_no_secondary 7 + high_ratio_and_no_secondary 5 (Hegele 2025 Table 3, parameter estimates ×10); max 100; ≥60 definite classical FCS; ≥45 very likely classical FCS",
      "max_score": 100,
      "score": 0,
      "all_tg_severely_elevated": false,
      "definite_classical_fcs": false,
      "high_tg_tc_ratio": false,
      "low_apo_b": false,
      "very_likely_classical_fcs": false
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "components": [
    {
      "factor": "early_htg_onset",
      "points": 0,
      "present": false
    },
    {
      "factor": "child_htg",
      "points": 0,
      "present": false
    },
    {
      "factor": "all_tg_severely_elevated",
      "points": 0,
      "present": false
    },
    {
      "factor": "high_tg_tc_ratio",
      "points": 0,
      "present": false
    },
    {
      "factor": "low_apo_b",
      "points": 0,
      "present": false
    },
    {
      "factor": "bmi_below_threshold",
      "points": 0,
      "present": false
    },
    {
      "factor": "abdominal_pain",
      "points": 0,
      "present": false
    },
    {
      "factor": "pancreatitis",
      "points": 0,
      "present": false
    },
    {
      "factor": "no_secondary_factors",
      "points": 0,
      "present": false
    },
    {
      "factor": "high_ratio_and_low_apo_b",
      "points": 0,
      "present": false
    },
    {
      "factor": "child_and_no_secondary",
      "points": 0,
      "present": false
    },
    {
      "factor": "high_ratio_and_no_secondary",
      "points": 0,
      "present": false
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "age_years": 40,
  "citation": {
    "authors": "Hegele RA, Ahmad Z, Ashraf A, et al.",
    "doi": "10.1016/j.jacl.2024.09.008",
    "id": "hegele-2025",
    "pmid": "39537503",
    "source": "J Clin Lipidol. 2025;19(1):83-94",
    "title": "Development and validation of clinical criteria to identify familial chylomicronemia syndrome (FCS) in North America"
  },
  "formula": "nafcs",
  "formula_expression": "NAFCS = early_htg_onset 12 (age_years ≥10 and htg_onset_before_age_10) + child_htg 12 (age_years 1-9) + all_tg_severely_elevated 13 (all fasting TG >880 mg/dL or >10 mmol/L) + high_tg_tc_ratio 8 (TG/TC >8 mg/dL or >3.5 mmol/L) + low_apo_b 12 (apo B <1.0 g/L or <100 mg/dL) + bmi_below_threshold 9 (BMI <25 kg/m2 or <85th percentile) + abdominal_pain 9 (recurrent abdominal pain without pancreatitis) + pancreatitis 16 + no_secondary_factors 11 + high_ratio_and_low_apo_b 7 + child_and_no_secondary 7 + high_ratio_and_no_secondary 5 (Hegele 2025 Table 3, parameter estimates ×10); max 100; ≥60 definite classical FCS; ≥45 very likely classical FCS",
  "max_score": 100,
  "score": 0,
  "all_tg_severely_elevated": false,
  "definite_classical_fcs": false,
  "high_tg_tc_ratio": false,
  "low_apo_b": false,
  "very_likely_classical_fcs": false
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• Dutch FH — Apply the Nordestgaard 2013 Table 1 Dutch Lipid Clinic Network score from caller-supplied LDL cholesterol plus family, clinical, physical, and DNA flags, and return the 0–26 score and definite, probable, possible, or unlikely classification. Not a diagnosis.
• Simon Broome — Apply the 1991 Simon Broome Register adult definite familial hypercholesterolaemia rule and return definite or not_definite from one lipid value plus a caller-assigned tendon-xanthoma flag.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
• exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.