United Kingdom, July 3 -- Jesy Nelson will "feel heartbroken" for the rest of her life after her twin daughters were diagnosed with spinal muscular atrophy.

The former Little Mix star gave birth to Ocean and Story - her first children with her ex-fiance Zion Foster - last year and doctors later confirmed both girls were battling SMA Type 1, a rare genetic condition that causes progressive muscle weakness, and Jesy has now shared the moment she was given the painful news.

In a trailer for her new Amazon Prime documentary Jesy Nelson: Life Changing, she is seen breaking down in tears as she says: "The genetic testing came back positive for spinal muscular atrophy.

"I can't believe this is happening. It's the most severe muscle disease a ...