What is the diagnosis?

HbE / beta thalassaemia compound heterozygote.

The alkali gel shows bands corresponding to HbC/E/O/A2, HbF and HbA. The lack of a C band on the acid gel, combined with a band at the Hb A/E/D/G/A2 zone and a HbF band suggests that the band is HbE. This is confirmed by capillary electrophoresis.

Assuming her partner has a normal genotype, what is the chance that her baby will be affected?

Her baby will be either HbE heterozygous or beta thalassaemia trait.

Which condition leads to an increase in the percentage of haemoglobin A2?

Beta thalassaemia trait.

What other genetic abnormality, if co-inherited, may ameliorate the severity of this patient’s condition?

Alpha thalassaemia or hereditary persistance of fetal haemoglobin.

If a person has a normal HbA2, can they still have beta thalassaemia? How so?

Co-inheritance of alpha thalssaemia, iron deficiency, a beta thalassaemia mutation causing only a minor reduction of beta globin chain synthesis or a deletion of the locus control region can all lower the percentage of HbA2, masking the presence of a beta thalassaemia.