Caleb Logan Bratayley -- Cause of Death Undiagnosed Heart Condition

YouTube star Caleb Logan Bratayley died from a rare heart condition that went undiagnosed for years.

Logan's family says the condition, called hypertrophic cardiomyopathy was undetected because Caleb never showed any symptoms -- and according to doctors -- there was nothing the family could have done. There is no cure for the congenital condition.

Caleb passed away unexpectedly in October at the age of 13.

Logan's sisters have since had their hearts tested and appear to be in the clear.

The family thanked everyone for their unconditional support and ended by saying, "We miss our baked potato everyday."