Almost 17 years since his father, John Ritter, passed away, Jason Ritter continues to navigate first-time fatherhood under the screen icon’s lasting influence.

Jason and his fiancée, New Zealand actress Melanie Lynskey, welcomed a baby girl in December 2018, and the couple have been relishing extra time at home with their “smart and wonderful” daughter amid the coronavirus pandemic.

“The main thing I continue to pass down, which was a huge thing from my dad and mom [Nancy Morgan,] is how they always made sure we knew we were loved,” Ritter tells ET Canada ahead of taking part in the Virtual 6th Annual Freeze HD fundraiser for the Huntington’s Disease Society of America. “They said it a million times. You can pass all kinds of stuff onto your kids, but the feeling of being loved, unconditionally, is so important – knowing you can mess up or fail and they’ll never go, ‘Well, we loved you until that moment. Too bad!’”

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“So, ‘I love you,’ and, ‘I am here,’ are the two main ideas we’re trying to pass onto our daughter,” Ritter continues.

As she nears her second birthday, Jason says his wee girl is also showing signs of having inherited a key piece of Ritter DNA – a love for the lens.

“We take videos of her and show her, then she’ll [imitate] the sound she makes to tell us which one she wants to watch again,” he says. “She’s mimicking herself, which is incredible. And, there’s been times we’ve caught her trying to recreate old videos. One of her favourites is playing with the hose and the other day she kept forcing me to press record, then running away, laughing and coming back like she was filming it again!”

He believes his father would get a chuckle out of seeing his granddaughter “hamming it up for the camera” just like he and his siblings have always done. It’s no surprise the toddler’s a natural entertainer, given her mom is also an award-winning actress, who rose to fame in Peter Jackson’s 1994 New Zealand film, “Heavenly Creatures”, before relocating to the U.S., where she has starred in “Togetherness” and “Two and a Half Men”.

And, if their daughter decides to follow them into showbiz, learning lines will likely be a breeze – Ritter has been “mind-blown” observing how much she absorbs.

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“I’ll say something in passing and days later, she’ll point to whatever I was talking about and say the word,” he says. “I’m like, ‘So you heard it, went away and workshopped it like, ‘How do I make that sound he made?’ then did it?’ That retaining quality is amazing, especially because it’s something I have trouble with. I live moment-to-moment like the ‘Memento’ guy and here she is holding onto information, letting it percolate, then coming out with something new. It’s amazing.”

While parenting is keeping the star busy, he’s also using current downtime to give back, sitting on the host committee of this year’s Freeze HD fundraiser on Sept. 26, alongside Bryce Dallas Howard, Kate Miner, Marianna Palka and Scott Porter. The online event will benefit those suffering from Huntington’s disease, a genetic degenerative brain disorder affecting a person’s physical and mental abilities.

Ritter learned about the disease in 1999 through then-girlfriend, Marianna, an actress/filmmaker whose father, Terry, died from the illness. Through the couple’s 10-year relationship, Jason painstakingly witnessed Terry’s deterioration.

“What’s awful is how much it takes away from people in such a painfully gradual way,” Ritter reflects. “The man I met was completely different from the man Marianna’s mother fell in love with, and who Marianna grew up with. I saw the disease take over and it felt overly-cruel. It’s hard to maintain a sense of fairness and justice in the world when such a lovely man’s put through this disease. It’s extraordinarily-painful to watch someone slowly lose control of mind and body.” Children have a 50 per cent chance of inheriting the defective gene. Initially reluctant to discover her fate, Marianna chronicled her journey getting tested in 2014 documentary, “The Lion’s Mouth Opens”, which he also appeared in.

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“It was my nightmare come true,” he recalls of finding out Marianna was positive, after the pair split but remained close friends. “I spent years wondering about it and when we were dating, if I would see the smallest facial twitch, I would get a zing of fear, thinking, ‘Is this the beginning of it?’ Fear always crept in.”

“That whole day I had a pit in my stomach, hoping she’d say, ‘I don’t have it,’ and this huge weight would be lifted,” he continues. “It was devastating. But she said, ‘Let’s put the boxing gloves on and fight this thing.’”

Ritter says that while progress is being made, such as breakthroughs in preventing the gene from being passed through generations, many continue to suffer or are pre-symptomatic and bracing themselves for the disease’s onset, like 38-year-old Marianna. It’s why he, actor brother Tyler Ritter and others got behind Freeze HD, which will this year celebrate the lives of Terry Palka and Hurumia Chidinma, and feature a silent auction and musical performances.

It’s a chance for entertainers to come together at a time when many showbiz projects remain on hold. In Jason’s case, he’s waiting to start filming season two of “Raising Dion”, teasing that viewers who loved the “comedy, heart, action and complicated issues,” of season one won’t be disappointed.

Meanwhile, fans hoping to see him reprise his role as Eric on Vancouver-based series, “A Million Little Things”, will be thrilled to hear that creator, DJ Nash, is “open to the idea.” “When he first brought it up, I was super-excited, but [Eric] burned a lot of bridges exiting that show!” Ritter says. “So, I do wonder how he’d bring me back, but it would be so fun.”

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