Mwepu received the sad news earlier this week after falling ill during the recent international break.
At just 24 years of age, Mwepu's condition has been described as heriditary and his risk of developing a cardiac arrest is high if he continues playing.
Muamba was similarly forced to retire at 24 after he suffered a cardiac arrest while playing for Bolton Wanderers in an FA Cup tie against Tottenham Hotspurs in March 2012.
"He's allowed to feel like his career has been taken away from him at such a young age," ex-England Under-21 midfielder Muamba, 34, told BBC Sport.
"At the same time, his loved ones need him around now. It would have been a lot worse if something bad had happened to him during a game of football."
"At that particular moment, you feel like this thing has been stolen away from you without you having a say in it," said Muamba, who has launched an initiative to teach cardiopulmonary resuscitation via messaging app Snapchat.
"But at the same time, you've got to look at the bigger picture - this is not about you any more. This is about everybody who's involved in a football club, it's about the players who you're playing with."
"I understand the emotions and being upset but it's better to be safe than sorry," added Muamba, who also played for Arsenal and Birmingham.
"You hope he will get the support he needs.
"I feel that we should give him the time and space to process everything. From there, if he ever wants to talk, I'm there for him."
Mwepu played in all six of Brighton's opening Premier League games this season.
He joined Brighton from Red Bull Salzburg last summer and made 18 appearances in the Premier League, scoring two goals and providing four assists.
Mwepu made 23 appearances for the Zambia national team and scored six goals.
