Twins in DOOL

While watching DOOL (DAYS OF OUR LIVES) the other day, when one character was speaking I wonder what ever happened to his twin brother in the “story”. Which made me think of another set of twins in DOOL, then another set. Then I took a mental inventory of all the sets of twins on DOOL that I have been exposed to. It is either 6 or 7 or 8 sets. I got confused trying to keep a running unwritten tally in my head. Doctor Marlina real-life twin was part of the story for a while. I think they should have a story line on what is in the water that causes so many twins in Salem.