BISMARCK, N.D. — North Dakota Rep. Kevin Cramer’s son has died at a Minnesota hospital after suffering from failing liver and kidneys.

The congressman had said his 35-year-old son, Isaac Cramer, was being evaluated by a “transplant team.” Spokesman Tim Rasmussen says he died early Thursday at the Mayo Clinic. He wouldn’t confirm the cause of death.

Cramer says in a Facebook post that he and his wife, Kris, were with their son when he died. The couple hasn’t publicly disclosed the cause of Isaac Cramer’s illness, but the congressman said his son now “feels no anxiety or urging for alcohol.”

Cramer recently launched his campaign for U.S. Senate. He’s hoping to unseat Democratic Sen. Heidi Heitkamp.