Raised Hb F analysis
HPFH is characterised in heterozygotes by levels of Hb F of 15-25% with normal red cell indices. Delta beta thalassaemia tends to have lower levels of Hb F (5-15%), microcytic, hypochromic red cells in heterozygotes with detectable chain imbalance. Accurate diagnosis is essential since HPFH is clinically benign compared with delta beta thalassaemia in which the individual may be dependent on blood transfusions throughout life.
HPFH and delta beta thalassaemia arise from large deletions of the beta globin locus on chromosome 11, all of which remove or destroy the expression of the delta and beta globin genes. There are also point mutations in the promoter of the gamma globin genes which can also give rise to HPFH.
Based on the clinical details, haematological data and ethnic origin, patients will be assessed on an individual basis for the best approach for clinical testing.
Please identify partner in referral if a fetal risk assessment is required.
Please provide full blood count (FBC) and HPLC screening results and iron levels as they become available.
Clotted samples are unsuitable for DNA analysis.
Blood Samples in in correct anticoagulant tubes may be rejected.
We accept DNA samples. Please provide at least 1-5µg of purified DNA
For prenatal diagnosis please refer to section for sample requirements.
Samples must be clearly labelled with the patients first name, surname, D.O.B, hospital number and the date the sample was taken. The details on the sample must correspond to the request form. Unlabelled samples will not be accepted.
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
London SE5 9RS
Last updated: 15/01/2020