Universal screening for hemoglobinopathies in today's multi-ethnic societies: How and when

Table 2 Genotype/phenotype correlation, indicative MCV/MCH values, HPLC/CE separations and presence of HbH or Hb Bart's and genetic risk in alpha thalassemia

Genotype	α-thalassemia	Phenotype	MCV	HPLC	HbH (adult)	Genetic risk for the
	Condition name		MCH	CE	Hb Bart’s (newborn)	progeny of carriers
αα/αα	Normal	Normal	Normal	Normal	Absent	None
					Absent
-α/αα	α+ heterozygous	Eventually anemic	borderline	Normal	Absent	HbH
					0%-5%
-α/-α	α+ homozygous	Mildly anemic	Low	Normal	Absent	HbH
				HbA2↓	5%-10%
--/αα1	α° heterozygous	Mildly anemic	Low	Normal	Absent	HbH or Hb Bart’s HF
				HbA2↓	5%-10%
--/-α2	HbH disease	Intermediate	Lower	HbH	0%-10%	HbH or Hb Bart’s HF
		hemolytic anemia		Hb Bart’s	10%-30%
				HbA2↓↓
--/--	Hb Bart’s	Severe intrauterine	Severe	No HbA or HbF in newborn	Hb Portland	Lethal to newborn.
	Hydrops Fetalis	hemolytic anemia	morphology		Hb Bart’s	Life threatening for mother

¹Rare positive cells after inclusion bodies staining;

²Many positive cells after inclusion bodies staining (Figure 2). MCV: Mean corpuscular volume; MCH: Mean corpuscular hemoglobin; Hb: Hemoglobin; HPLC: High performance liquid chromatography; CE: Capillary electrophoresis.