Mother’s Day passed for the Fry family in the most bittersweet of manners. Their matriarch passed away March 24, 2008 after a long and valiant battle with an evil disease.

But the disease did not leave with their mother. Unfortunately, the Frys will forever have this legacy. However, unlike some cases in which there are those fighting a losing battle, the Frys are choosing to fight back.

This is their story.

WHAT IS OSTEOPETROSIS

Osteopetrosis, not to be confused with osteoporosis, is also known as Marble Bone Disease or Albers-Schonberg disease. It is an extremely rare, inherited disorder caused by mutations on the CLCN7 gene, whereby the bones harden, becoming denser.

Bone growth is a balance between osteoblasts (cells that create new bone tissue) and osteoclasts (cells that destroy old bone tissue). Sufferers of osteopetrosis have impaired osteoclasts function; meaning old bone tissue is not destroyed and removed from the body. This results in bones that are denser and more brittle than normal bones. Mild forms of osteopetrosis may cause no symptoms and present no problems; however, more severe forms can result in stunted growth, deformity, increased likelihood of fractures, bone infection, enlarged spleen, kidney problems, anemia and other blood issues. Osteopetrosis can also lead to blindness, facial paralysis, and deafness due to increased pressure put on the nerves by the extra bone.

There are two types of osteopetrosis: a genetically dominant form called Autosomal Dominant Osteopetrosis and a genetically recessive form called Autosomal Recessive Osteopetrosis (ARO). Each of us carries two copies of the CLCN7 (chloride channel 7) gene (one from the mother, one from the father). Autosomal Dominant Osteopetrosis occurs when a person receives one mutated (or “bad”) CLCN7 gene from one parent and one normal CLCN7 gene from the other parent. Likewise, Autosomal Recessive Osteopetrosis occurs when a person receives two copies of the mutated CLCN7 gene, one copy from each parent.

Osteopetrosis can be diagnosed in two ways: through skeletal x-rays and through genetic testing of the CLCN7 gene. X-rays are the most common form of diagnosis. Films of osteopetrosis patients will have an unusual density with a chalky white appearance. Bone density tests and bone biopsies can confirm the diagnosis, while other tests, such as CAT scans or MRI can be performed to evaluate any potential complications.

Genetic testing of the CLCN7 gene can also be performed. This is especially useful if a person would like to know whether they are a carrier of the mutated CLCN7 gene. Remember, that carriers are the one in three people who have a mutated CLCN7 gene, but are disease free. Genetic testing is the only way to determine whether a person is a carrier, and thus, if a person has a 50/50 chance of passing the mutated gene to each of their children.

The less severe form of osteopetrosis, Autosomal Dominant Osteopetrosis, affects approximately 1,250 people in the United States. Autosomal Recessive Osteopetrosis, or Malignant Infantile Osteopetrosis, is even more rare, affecting only 8 to 40 children in the United States each year. It is difficult to estimate how often the different forms of osteopetrosis occur worldwide. The disease could be much more prominent, but lack of communication and knowledge of the disease could affect documentation of the disease.

The question lingers: “If osteopetrosis is so rare, why should I care?” As mentioned before, normal bone growth is a balance between osteoblasts and osteoclasts. In osteopetrosis, the osteoclasts do not function properly and old bone tissue is not being destroyed and removed from the body.

It is the mission of the International Osteopetrosis Association (IOA), the Fry family’s foundation, to fund research specific to studying the function of osteoclasts. In understanding how these cells function, answers may be found to whole host of other bone mineralization disorders (such as osteoporosis).

See part 2 in Wednesday’s Rushville Republican.

Elizabeth Gist can be contacted at elizabeth.gist@rushvillerepublican.com or at (765) 932-3111 ext. 109. Add a comment to this story at www.rushvillerepublican.com.