Seokjin:

High school year: senior
Disability: Blindness also has cancer.
He lost his vision when he was young due to a car accident and uses a cane to get around.

He is Namjoon's mate and is 9 months pregnant.

Blindness: Complete or partial loss of vision

(Photo edited by me)

Namjoon:

High school year: Junior
Disability: deafness, he can hear with the help of hearing aids and is slowly loosing his hearing. He can still speak normally but will use sign language with Taehyung.

He is also Jin's mate

Deafness: a degree of hearing loss such that a person is unable to understand speech, even in the presence of amplification.

Yoongi:

High school year: senior
Disability: muscular dystrophy, he wears a brace on his legs. He was born with it

He is the mate of Jimin

Muscular Dystrophy: A group of genetic diseases that cause progressive weakness and loss of muscle mass.

Jimin:

High school year: sophomore
Disability: Amputee below the knee. He lost his right leg from a hiking trip and wears a prosthetic leg.

He is Yoongi's mate

Amputation:  a removal of a limb by trauma, medical illness, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventive surgery for such problems.

Hoseok:

High school year: Junior
Disability: paralyzed and uses a wheelchair like Jungkook. He lost the feeling in his legs from a car accident and uses a wheelchair to get around.

Paralyzed: Damage to any part of the spinal cord or nerves at the end of the spinal canal. A traumatic spinal cord injury may happen because of a sudden blow or cut to the spine.

Taehyung:

High school year: sophomore
Disability: muteness due to abuse from his father. He communicates by writing on a note pad and sign language with Namjoon.

He is Jungkook's mate

Muteness: an absence of speech while conserving or maintaining the ability to hear the speech of others.

Jungkook:

High school year: freshman
Disability: multiple sclerosis. He uses a wheelchair to get around since he was born with it.

He is Taehyung's mate

Multiple Sclerosis: A disease in which the immune system eats away at the protective covering of nerves.