Required section · Section 1 of 6
Opening laboratory problem: a result that cannot name itself
An adult EDTA whole-blood specimen is assessed in the complete opening result table: CBC, reticulocytes, morphology, HPLC fractions, and transfusion history appear there once.
The question is not whether the printout has an S label. The question is whether the combined evidence supports HbS presence and what still separates trait, disease-pattern families, coinheritance, or transfusion effect. The HPLC result measures fractions in method-specific retention windows. It does not turn a measured S-window fraction into a genotype.
Start by holding the HbA fraction open as a question rather than assigning it to the patient. Donor red cells can mask a hemoglobinopathy or add a donor fraction after transfusion. The morphology and reticulocytosis are supportive evidence in context, not a molecular result. Release a bounded interpretation only after the specimen history and a complementary method are reviewed.
Illustrative drawing — this picture was drawn rather than captured.
| Finding | Result | Interpretive context |
|---|---|---|
| Hemoglobin | 9.1 g/dL | Low against 12.0–16.0 g/dL illustrative interval |
| MCV | 86 fL | 80–100 fL illustrative interval |
| Absolute reticulocytes | 210 × 10^9/L | 30–100 × 10^9/L illustrative interval; high |
| Smear | Polychromasia, target cells, occasional sickle forms, Howell-Jolly bodies | Supportive in context, not molecular |
| HPLC | HbA 31.0%; S-window 54.0%; HbF 12.0%; HbA2 3.0% | Fractions in method-specific windows |
| Transfusion | Red-cell transfusion 18 days earlier | HbA may include donor cells |
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