alpha thalassemia-1 (alpha-thalassemia trait, cis form)

Epidemiology

• found in Asian & Mediterranean populations

Pathology

hydrops fetalis found in these populations

Genetics

• - -/ alpha alpha (2 of 4 functional alpha globin genes)
• two functional alpha globin genes on each chromosome 16 (deletion or malfunction of 2 genes on same chromosome)

Laboratory

• complete blood count
  • mild anemia: blood hemoglobin of 12-13 g/dL; 10 g/dL
  • MCV 70-80 fL (microcytosis); case presented with MCV of 62 fL
• peripheral smear:
  • rare red blood cell inclusions
  • hypochromia & microcytosis
• hemoglobin electrophoresis:
  • Hgb A (85-95%)
  • hemoglobin A2 normal
  • hemoglobin F normal

More general terms

• alpha thalassemia