A B.C. teenager who suffers from a genetic condition affecting her connective tissue is sharing her frustration over not being allowed to attend her high school prom, due to too many unexplained absences.

Triss Hunter says there’s a good reason that she's missed classes at Ecole Mission Senior Secondary School in the Fraser Valley. The student suffers from Ehlers-Danlos Syndrome – a disorder that affects the connective tissues supporting the skin, bones and blood vessels.

"I have chronic pain and chronic dislocation and my dislocations can happen at any moment," she told CTV Vancouver.

Hunter says administrators told her she wouldn't be allowed to attend her high school prom next week, saying she has missed too much school.

"I tried to explain that I have to go to physiotherapy three times a week and I have to go to doctors' appointments at any random time," she said.

The school says while it won't discuss individual students, it argues that its policies are very clear.

Angus Wilson – the superintendent of school district 75 that encompasses Mission -- says parents and students are aware of the criteria required to explain an absence and parents are given up to two weeks to notify the school after the absence.

"(Mission Secondary School) is very flexible in making allowances and adaptations for every student and their individual situation," wrote Wilson.

He added that students are permitted to attend prom with excused medical absences.

Hunter's mother says she's frustrated by the whole ordeal.

"I am angry. I am frustrated and very disappointed because I never got to go to my prom and this would be really exciting for her," Sarah Hunter said.

With a report from CTV Vancouver’s Penny Daflos