Sickle cell disease: diagnosis and health maintenance: Viva

This is a newborn-screen diagnosis of sickle cell anaemia, HbSS, in a well eight-week-old boy. The structured oral runs from the confirmation of the diagnosis through the molecular basis, the immediate prophylaxis, the hydroxyurea decision, and the stroke-prevention strategy, and it ends with the trial evidence. ^[5]

Opening: confirm the diagnosis

Examiner. The newborn screen shows an FS pattern. What does that mean, and how do you confirm it? ^[5]

Candidate. The FS pattern on high-performance liquid chromatography means the child has haemoglobin F and haemoglobin S with little or no haemoglobin A, which is the pattern of HbSS, sickle cell anaemia. I confirm it with a repeat test on a fresh sample by the same method, and I do not need further testing unless the result is ambiguous, in which case deoxyribonucleic acid testing of the HBB gene settles the mutation. The child is well at eight weeks because fetal haemoglobin protects the cell, and the complications begin only as it falls through the first year. ^[5]