fetal haemoglobin , auch: fetal hemoglobin

Fetal haemoglobin is present in infants six months and younger and Azaria was nine weeks old at the time of her disappearance.

This is achieved, in part, by reactivating fetal haemoglobin production in place of the haemoglobin S that causes sickle-cell anaemia.

Fetal haemoglobin (HbF) is structurally different from normal adult haemoglobin (HbA).

At the placenta there is a higher concentration of 2,3-DPG formed which binds more readily to adult haemoglobin and not to fetal haemoglobin.

Symptoms of sickle cell anaemia are seldom manifest before the age of six months when the level of circulating fetal haemoglobin falls to the adult level.

The prosecution had successfully argued that the pivotal haemoglobin tests indicated the presence of fetal haemoglobin in the Chamberlains' car and it was a significant factor in the original conviction.

The exoneration was based on a rejection of the two key points of the prosecution's case-particularly the alleged fetal haemoglobin evidence-and of bias and invalid assumptions made during the initial trial.

The key evidence supporting this allegation was the jumpsuit, as well as a highly contentious forensic report claiming to have found evidence of fetal haemoglobin in stains on the front seat of the Chamberlains' 1977 Torana hatchback.

One particularly important example of such an interaction is where sickle cell anaemia is co-inherited with the benign condition hereditary persistence of fetal haemoglobin (HPFH), in which levels of the fetal form of haemoglobin HbF do not fall as the patient grows.

Evidence was also presented that adult blood also passed the test used for fetal haemoglobin, and that other organic compounds can produce similar results on that particular test, including mucus from the nose, and chocolate milkshakes, both of which had been present in the vehicle where Azaria was allegedly murdered.