LatticeMLS
Menu
Module overview
Section 5 of 6 · Open sections

Required section · Section 5 of 6

Learner decision

Rank the evidence in the case before naming a pattern. The strongest compatible combination is marked microcytosis, mild anemia, relatively increased RBC count, target cells, ferritin that does not support iron deficiency, and increased HbA2 on the local method. Each item changes the differential. HbA2 alone would be insufficient because iron status, variants, and method performance can change its interpretation.

The case supports a beta-thalassemia carrier pattern. Molecular or family correlation is appropriate when the pattern is discordant or clinically requested; alpha-thalassemia coinheritance remains a possible limitation.

For a microcytic adult pattern with nondiagnostic adult separation, alpha-thalassemia trait remains possible. For HbH disease, HbH detection ranges after the fetal-to-adult switch are 0.8%-40% (Alpha-Thalassemia GeneReviews), but molecular testing is needed to establish involved HBA1 and HBA2 variants. Hb Bart hydrops fetalis syndrome also requires molecular confirmation for diagnosis and family studies. Select molecular or family correlation when the answer will resolve a material limitation, not use a fraction percentage as a substitute.

Illustrative drawing — this picture was drawn rather than captured.

A workflow moves from CBC and iron status to age-specific separation and pattern correlation, with molecular or family study below for unresolved or clinically important findings. It states that normal adult separation does not exclude alpha-thalassemia trait.
Figure 1Correlation pathway for a possible alpha-thalassemia pattern.

Ordering exercise

Put the evidence workflow in the order that prevents a fraction result from becoming a premature genotype call.

  1. 1. Interpret age-appropriate fractions

    Review HbA2, HbF, HbH, or Hb Bart with the separation method.

  2. 2. Choose correlation

    Use second-method, molecular, or family correlation when justified.

  3. 3. Review CBC and smear

    Identify the anemia, index, count, and morphology pattern.

  4. 4. Confirm context

    Check iron, age, transfusion history, and local method limits.

Knowledge checks

Reading and checks are open. Sign in only to save.

Knowledge check 1

An adult has persistent microcytosis, iron status that does not support deficiency, and nondiagnostic adult hemoglobin analysis. What remains appropriate?

Choose one option.

Section status

Finish this section

Reading and checks are open. Sign in only to save.

The module finishes after every required section is marked done and every check in those sections is correct.