Caleb Logan: YouTube Star's Family Has History Of Heart Conditions [PHOTOS + VIDEO]

The family of YouTube reality stars whose 13-year-old son and brother suddenly passed away last week are sharing more details about their tragic loss.

Caleb Logan LeBlanc - who along with his two sisters and mother and father go by the last name Bratayley when appearing in videos - was rushed to the hospital from his home in Arnold, Maryland and died soon after.

A fatal heart condition known as hypertrophic cardiomyopathy may be to blame for the death of Caleb Logan, according to his mother, Katie.

The teenager died unexpectedly on October 1, after having suffered from what his mother called on Instagram an “undetected medical condition.“ Now, she has revealed that the heart condition, which can be deadly, actually runs in their family.

"Caleb's death has raised many questions about how and why this could happen to a seemingly healthy boy. Sadly, tests have confirmed that Caleb passed away from an undetected medical condition," the family wrote on their Facebook page.

"We'll have more definitive answers in the coming weeks but ask that you help us celebrate his life instead of focus on his death."

Caleb’s family has a history of hypertrophic cardiomyopathy, they have confirmed to ABC News. The deadly condition, which can have very few or no symptoms entails the heart muscle becoming “abnormally thick,” according to the Mayo Clinic. The disease can lead to abnormal heart rhythms which can sometimes result in death.

The Bratayley family, including Caleb's sisters Annie, 10, and Hayley, 7, began recording their daily lives on YouTube in 2010, usually releasing one video every week.

They have over 1.7million subsrcibers on YouTube, and during the series, Caleb - a history buff - met and interviewed Republican presidential hopeful Cary Fiorina, as well as travelling to Hillary Clinton's campaign headquarters in Brooklyn to speak with supporters.

A tribute video to Caleb released over the weekend has over 3million views.

Watch the video below.

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