Final answer:
Apolipoprotein B-48 is the gene product that escapes Nonsense-Mediated Decay despite a premature stop codon, due to mRNA editing by APOBEC1 which leads to production of a functional protein necessary for chylomicron assembly and secretion in the intestine.
Step-by-step explanation:
The gene product discussed in our lectures that escapes Nonsense-Mediated Decay (NMD) despite its naturally-occurring premature stop codon is apolipoprotein B-48. Apolipoprotein B-48 is produced in the intestine from the same gene that encodes apolipoprotein B-100, which is made in the liver. However, due to a mechanism involving the editing of the mRNA by an enzyme called APOBEC1, a stop codon is created prematurely. This editing event leads to the formation of a shorter protein, apolipoprotein B-48, which plays a crucial role in the assembly and secretion of chylomicrons, without being targeted by NMD.