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Beyonce and her sister Solange Knowles got tested for a mutated gene called a BRCA2 gene after their dad Mathew Knowles was diagnosed with breast cancer.

The former Destiny's Child manager revealed his frightening diagnosis in an interview with Good Morning America that aired on Wednesday, Oct. 2, the second day of Breast Cancer Awareness month.

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In his chat with Michael Strahan, Mathew, 67, revealed that the first call he made when he learned of his health battle was to his famous daughters - because they are at high risk to be carriers of the same gene.

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"The first call was to my family, because this is genetics," said Mathew, pictured with daughter Solange. "It means that my kids have a higher chance, a higher risk (of getting cancer), even my grandkids have a higher risk, and they handled it like they should - they went and got the test," Mathew explained. He didn't reveal the results of the tests.

Everyone is born with BRCA genes that help to suppress cancerous tumors. But Mathew's gene has a mutation on it that led to his breast cancer diagnosis.

He added that after being told he had breast cancer, he was warned that he might be diagnosed with prostate cancer, pancreatic cancer or melanoma later on. He will continue to have regular mammograms and other examinations to ensure he is free from the disease.

Mathew is a father of at least seven children - five of his children were fathered outside of his marriage to Beyonce's mother, Tina Knowles, who filed for divorce and is now happily married to retired actor Richard Lawson.

Mathew fathered two young children with current spouse Gena Avery whom he married in 2013. He also has a son, Nixon, with Alexsandra Wright and a daughter with TaQoya Branscomb. And there is widespread belief that he is the biological father of Destiny's Child original member Kelly Rowland.

Mathew told Strahan he had his breast removed to prevent the cancer from spreading to his lymph nodes.

"I'm doing really well. I had my surgery the last week of July and now I'm going through all the steps for recovery."

So far, Beyonce has not commented on her father's diagnosis.