http://learn.genetics.utah.edu/content/disorders/chromosomal/cdc/ Day 104 has 39 protein-coding genes (browser view) and is the beginning of Chromosome 5.
When this tip of Chromosome 5 breaks off, it causes Cri du chat syndrome, a rare developmental disorder. The severity of the disease depends on how much of the 5p arm breaks off, but it’s not known which of the missing genes is important.
Click here to see all 8644678 letters of Day 104.