United Kingdom, June 13 -- Scott Porter's marriage went through a "complete change" when his wife discovered that she had Huntington's disease in her family.

The 45-year-old actor has been married to casting director Kelsey Mayfield since 2013, but when she discovered that her mother had the brain disorder that affects movement, thinking, and behaviour, he noted just how "quickly" it had altered things between them.

He told People: "That was definitely a moment of complete change, as far as the trajectory of my wife's and my relationship.

"It can really tear through families very quickly."

Hungtingo's disease is genetic, meaning that each child of a parent who suffers from it has a 50 per cent chance of inheriting it themselves but th...