At 10:30 p.m., kids at most summer camps are winding down for the night. But at a camp in Craryville, New York, the fun is just beginning.

Kickball, Frisbee, and singalongs at Camp Sundown all happen after dark because that is the only time the kids can be outside. Most of them are allergic to the sun. Just a few seconds of sun exposure can cause immense pain or even life-threatening cancer.

Morgan McKillop, 8, was diagnosed with erythropoietic protoporphyria, or EPP, when she was 2. The rare genetic disorder, characterized by photosensitivity, is caused by an enzyme deficiency.

This is Morgan's third summer at Camp Sundown, a program founded by Caren and Dan Mahar in 1996 after their daughter Katie was diagnosed with xeroderma pigmentosum, known as XP. The rare disease affects just one in a million people, whose genes lack the ability to process sun-damage.

After Katie's diagnosis, the Mahars were devastated. They knew that if they didn't do something, their daughter might be alone for the rest of her life. That something came first in the form of the Xeroderma Pigmentosum Society, a support and information group, and a year later Camp Sundown was born. Days are spent doing crafts, yoga and playing games indoors. Nights outside stretch into the early mornings.

That is a shared reality here. Mary and Ray Ventrice's daughter Gia, 6, was diagnosed with EPP as a toddler. The condition has taken a toll physically and emotionally. Her father said it affected her spirit. But little more than 24 hours after Gia got to camp, her spirit seemed to soar.

Camp Sundown is a family affair, so the campers with sun sensitivities come with their entire families—moms, dads, siblings. Often those family members get just as much out of the experience as the campers do.

Cathy and Brent Macfarlane's son Jack has EPP. This is the second summer they've made the trip from Ontario. Like most families at Camp Sundown, they didn't know anyone else dealing with a condition like their son's until they came here. They said they felt a sense of extended family at the camp.

In addition to the endless activities, one-on-one visits with medical experts, and the campfire s'mores, the week-long session of Camp Sundown is completely free for every family.

So Camp Sundown relies entirely on charitable donations. The Mahars said that each week-long session costs about $20,000, which they scrape together. But it is worth it because each camp session is a bright spot in the campers' lives. They run free like every child is supposed to, the Mahars said, and they are happy to be alive and in each other's company.

--STACEY DELIKAT

What does Xeroderma Pigmentosum mean in English?

They're known as 'Children of the Moon' -- youngsters struck with the genetic disorder 'xeroderma pigmentosum', which makes exposure to sunlight potentially fatal. Restrictions on movement mean many struggle to live normal lives. But a school in France has been making some changes to accommodate one boy living with the rare condition.Duration: 02:12

Nuestras invitadas especiales nos hablan sobre esta condición especial que afecta a muchas personas en nuestro país y la cuál es muy desconocida. Descubra más sobre esta afección

#د_احمد_عنانى
#genodermatoses

00:00 Porokeratosis
16:55 Ectodermal dysplasia
28:55 xeroderma pigmentosum
47:10 Pseudoxanthoma elasticum
1:09:10 x dominant disease
1:10:15 incontinentia pegmenti