In 1982, with another Nature paper, Goodman did the same for the DNA sequences of the hemoglobin genes.
It occurs when a child inherits two sickle hemoglobin genes, one from each parent.
The sickling occurs because of a mutation in the hemoglobin gene.
It results from the failure of "a pair of very important hemoglobin genes" to produce the red cells that carry oxygen to the tissue.
There is more than one hemoglobin gene.
Sickle cell anemia is caused by the inheritance of a variant hemoglobin gene (HgbS) from both parents.
Although they do not manufacture hemoglobin, remnants of hemoglobin genes can be found in their genome.
In only one of the icefish species, Neopagetopsis ionah, there is a more complete, but still nonfunctional hemoglobin gene.
While they do not use hemoglobin anymore, remnants of hemoglobin genes can be found in their genome.
The entire sequence of several thousand bases is the hemoglobin gene.