Mariah Carey's mom Patricia and sister Alison died on the same day over the weekend, PEOPLE can confirm.

My heart is broken that I’ve lost my mother this past weekend.

Sadly, in a tragic turn of events, my sister lost her life on the same day,"

the Grammy-winning singer, 55, said in an exclusive statement to PEOPLE.

"I feel blessed that I was able to spend the last week with my mom before she passed," adds Mariah

"I appreciate everyone’s love and support and respect for my privacy during this impossible time."

No other details, including Patricia and Alison's causes of death, are known at this time.

Patricia, who was previously married to Alfred Roy Carey,

was a Juilliard-trained opera singer and vocal coach before the couple welcomed Alison, Mariah and son Morgan.

The parents later divorced when the "Hero" singer was 3 years old.

Mariah's relationship with her mother — from whom her vocal talents were inherited — was complicated throughout her life.