The fact that the rare disorder was genetic meant there was a one-in-four chance that her toddler daughter Abby, now three, would have it too.
Tragically, just three weeks later, Pam and her partner Christ were told she did.
Both girls suffer from Niemann-Pick Type C1 - and the condition will claim their lives all too soon.
'We had to deal with the thought that we would eventually, and sooner rather than later - lose our family to this cruel disease,' Pam, a 44-year-old business developer, tells New Idea.
'It didn't seem fair that both our gorgeous children were going to suffer and eventually die, os Chris and I knew that we had to pick ourselves up and fight for them. We cannot - and will not - let our daughters die.'
Pam and Chris, a 45-year-old attorney, met through the site Match.com in October 2006.
The couple, from Austin, Texas, became serious quite quickly and they knew they would get married one day.
In June 2009, Pam found out she was pregnant.
As their newborn daughter, Belle, grew older she failed to meet her developmental milestones.
Her speech wasn't where it should have been and when she was four and a half, she often tripped when she was walking.
Worried, Pam took Bell to see her paediatrician and tests followed. In March 2016, a genetics expert called them.
'We were told to go there the next morning,' recalls Pam. 'It was torture waiting - I don't think Chris or I slept that night.
'The doctor told us the next morning that Belle was suffering from Neimann-Pick Type C1 - it's a horrific genetic disease where in time, children slowly regress until they can't walk, talk, eat or function properly.
'The worst of it is that dementia will set in and eventually the child can't even recognise their own parents or siblings. Most children die by the time they are 10, although some do live longer.'
The disease is caused by both parents carrying the same rogue gene.
'I knew this was a death sentence for my daughter. The doctor told me to go and enjoy our time together and live life as best we could.'
Devastatingly, the doctor also warned that Abby - who was born in June 2014 - would also need to be tested for the disease.
She was 20 months old when the tests came back positive.
'Having two girls with this is totally heartbreaking,' Pam says. 'And while it is a rare, cruel disease, we are hearing of other families all the time who are suffering and being diagnosed. There has to be more research. We need to find a way to slow . down the disease, but we also need to find a cure.'
To donate towards Abby and Belle's medical expenses visit: gofundme.com/savingbelleandabby
For the full story see this weeks issue of New Idea - out now!