Based on limited published evidence, TYW1B is a probable component of the wybutosine biosynthesis pathway. It catalyzes condensation of N-methylguanine with pyruvate carbons to form 4-demethylwyosine, an intermediate in wybutosine biosynthesis—a hypermodified guanosine found in eukaryotic phenylalanine tRNA. TYW1B exhibits protein binding capability and participates in wybutosine biosynthetic processes. Clinical reports identified frameshift mutations in TYW1B associated with congenital midline cervical cleft 1 and gene disruption in complex chr7 rearrangements 2, though these associations require further investigation.