They saw it in his eyes...

When Jackie and Olin Arnold had their first child, it looked like everything was going according to plan — they had dreamed of starting a family and now that dream was coming true. At first everything seemed perfect and their son Logan appeared to be healthy.

Logan was a happy baby and always had a smile on his face. But Jackie and Olin quickly began to notice things about him that didn't seem quite right.

You can watch this video to find out more about Logan's story:

Logan's face was very elongated and his eyes were set very wide apart. He also had upturned earlobes. According to Jackie, he looked more like "an old man" than a baby boy.

Jackie and Olin could sense that something wasn't right. When Logan was only 10 days old, he abruptly stopped feeding. They knew they had to take him to the doctor and find out what was going on.

Doctors performed emergency surgery to keep Logan alive, but were unable to make the vital connection between Logan's physical characteristics and his loss of appetite.

Doctors diagnosed Logan with an intestinal disorder, but Olin wasn't convinced that that was the extent of it, given that he was missing a lot of his infant milestones. He started doing research on the internet and soon made a life-changing discovery.

Olin did a search using all of Logan's symptoms and his personality traits, particularly the fact that he always seemed to be happy. This led him to some very rare genetic syndromes that few doctors knew about.

"I started looking at pictures of the kids and I found a little girl in Ireland who could have been his doppelganger," explained Olin. This little girl suffers from Mowat-Wilson syndrome, an extremely rare condition with only 300 known cases worldwide. Olin was convinced that Logan was suffering from the same illness.

A blood test at the geneticist confirmed it. Mowat-Wilson syndrome generally causes considerable intellectual disability and most sufferers never learn to speak properly.

Like half of all people who suffer from Mowat-Wilson syndrome, Logan also suffers from Hirschprung's disease, a very painful intestinal disorder. The disorder is so debilitating that the young boy needs help just to have a proper bowel movement.

But all this suffering doesn't affect Logan’s cheerful, loving and sweet personality. According to his mom, "he's the happiest kid in the world."