Day 9 contains 27 protein-coding genes – a very gene-sparse region. So it is predictable that the most-cited gene in this region is more arcane than the stars of other regions. It is ACADM (acyl-Coenzyme A dehydrogenase, C-4 to C-12 straight chain), encoding an enzyme that breaks down medium-chain fatty acids. Problems with this gene can cause a rare metabolic disease.
ACADM is billions of years old, because it is found in both bacteria and humans. Sequence analysis suggests that we didn’t inherit our ACADM directly from bacteria, but they were in the bacteria that eukaryotes engulfed that became mitochondria (endosymbiosis.) Even though the ACADM gene is now in the nuclear genome, the protein still does its work in the mitochondria!
Click here to see rs77931234, the most common mutation in ACADM causing MCAD deficiency. The frequency of this mutation is about 0.5% on European chromosomes.