When they met as a group for the first time, Leta, Liam, and Nadira seemed to bond instantly. All three are under 4 feet tall, have similar mannerisms, wide-set eyes, and bubbly personalities. They live with chronic respiratory problems and other medical challenges, in addition to cognitive and physical developmental delays.

“They look more like siblings than their actual blood siblings,” said Melissa Ashton-Grant, mother of Nadira. “To see how they interacted with each other, it felt right.”

The children’s similarity was no coincidence — and confirming and understanding their connection was no small matter. The three families gathered in March to celebrate because researchers at The Children’s Hospital of Philadelphia had discovered the rare genetic mutation their children share, and had given their cryptic constellation of symptoms a name: CHOPS Syndrome. CHOPS is an acronym that stands for Cognitive impairment and coarse facial features, Heart defects, Obesity, Pulmonary involvement, Short stature and skeletal dysplasia (abnormal bone development).