For Stefanie Wilderdyke of Adel, Iowa, the answer seems obvious. She and her sister have suffered a staggering array of health problems — lupus, fibromyalgia, Raynaud’s disease (which causes numbness and coldness in the extremities), Sjogren’s syndrome (an immune system disorder), hypothyroidism and endometriosis.
“My sister and I always wondered, with our dad having served in Vietnam, why is this happening?” she said.
But for scientists, the answer is: We don’t know.
In part that’s because there hasn’t been much research into what are called “paternally mediated” birth defects. But scientists also say it’s hard to determine the effects of Agent Orange exposure.