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Haemoglobin inheritance education

See how two confirmed results can combine

Build a Punnett square for AA, AS, AC, SS, SC, or CC laboratory results. The percentages describe each pregnancy independently—they do not diagnose anyone, predict one child, or direct relationship or reproductive decisions.

  • Lab results required
  • Per-pregnancy probabilities
  • Runs locally

A screening label or remembered result may be incomplete

Use results confirmed by a qualified laboratory or clinician. This simplified explorer covers only A, S, and C allele combinations; it does not cover beta-thalassaemia or other haemoglobin variants, resolve unclear notation, or replace confirmatory testing and genetic counselling.

Step 1

Confirm the source, then enter both results

No names, dates of birth, medical-record numbers, pregnancy details, or contact information are needed.

The labels above distinguish trait from disease for education. They do not interpret a person’s symptoms, severity, prognosis, or care needs.

Official context and freshness

Sources checked 26 July 2026

These sources support the inheritance, trait/disease, screening, and counselling boundaries. They do not validate any user-selected result.

CDC: About sickle cell diseaseSickle cell disease is inherited; HbSS and HbSC are among its forms, and newborn screening can identify SCD. CDC: Sickle cell traitTrait differs from disease; the AS × AS example is 25% AA, 50% AS, and 25% SS for each pregnancy. NIH/NHLBI: Sickle cell traitTrait has one S and one A allele, does not turn into SCD, and can be identified by testing. NIH/NHLBI: Pregnancy and reproductionGenetic counselling can help people understand inheritance and available testing questions.

Method and limits

How the Punnett model works

Each selected result contains two letters. The model crosses each letter from the first result with each letter from the second result, producing four equally weighted cells. Matching cells are grouped, so each unique genotype receives 25%, 50%, or 100% in this simplified Mendelian model.

The order of the two selections does not change the distribution. The model deliberately does not estimate clinical severity, symptoms, treatment, life expectancy, population burden, testing prices, or the outcome of an individual pregnancy.

Does “AA” mean a person has no health condition?

No. In this page it means only that the simplified haemoglobin selection is AA. It does not assess any other gene, blood disorder, symptom, or health condition.

What if a report uses different notation?

Do not translate or guess the result yourself. Ask the laboratory, clinician, or genetic counsellor to explain it. This page supports only AA, AS, AC, SS, SC, and CC.

Can this tool recommend a reproductive option?

No. It supplies neutral inheritance education only. A qualified clinician or genetic counsellor can explain testing options, limitations, timing, access, and personal implications without the calculator making the decision.