A heredity map outlining the incidence of PXE. Squares represent males and circles females. Light beige represents a normal gene; tan represents a PXE gene mutation. Only those who receive a copy of the PXE gene from both parents (solid tan squares and circles) will express the disease.

What is PXE?

Nor were the Terrys able to find out much more about PXE in a nearby medical library. They discovered that the disease was very rare (most estimates ranging from 1 in 50,000 to 1 in 100,000 people afflicted with PXE).

They also read that PXE “mineralized” cells -- that is, caused excess calcium to be deposited in the body’s connective tissue, which led to vision problems, stomach bleeding, cardiovascular problems, and sagging skin.

And they discovered that the disease was passed on genetically, in what is called an “autosomal recessive manner”: that is, children developed PXE only if they received two copies of a gene mutation associated with PXE, one from each of their parents.