MilliAnna's family from Ridgeland, South Carolina, all had the trait passed down from her great-grandmother Jaonne, 59, to her grandmother, Jennifer, 41, and to her mother, Brianna, 23.
Each of the women was reportedly born with a condition that causes a lack of pigmentation in a patch of skin or hair called Poliosis, Caters News reports.
Speaking with InsideEdition.com, MilliAnna's mother, Brianna Worth said, "My whole life growing up, I took it as a birthmark."
Unsure of just how far back in their lineage the trait can be traced, since Jaonne was adopted, Brianna says she was thrilled when she realised she had passed the trait on to her daughter.
She says, "I'm going to tell her, 'you're unique, you're pretty, you're beautiful."
Brianna, however, says she had not been eager to embrace the trait as a younger girl and expressed hopes that her daughter would embrace their rare trait.