The six-month-old son of missing Dalkeith man Ross Taylor had open heart surgery just a few months ago.
Thirty-year-old Ross went missing from his Dalkeith home at noon on Sunday, leading his partner Laura D'Arcy to make an emotional appeal for the public's help to find him earlier today.
In that press conference, it was revealed that six-month-old Lewis underwent open heart surgery back in January.
It was also revealed that colleagues at energy firm SSE had joined the search for Ross.
He is described as white, 5ft 9ins tall, of skinny build, with short light brown hair and was last seen wearing grey jeans, a black jumper and white Converse trainers.
He was last seen at his home in the Mayfield area around noon Sunday and there are concerns for his welfare.