Jill Pinarowicz’s life has been shaped by a mutation in her mother’s DNA. The genetic error gave her two brothers a rare disease called Wiskott-Aldrich syndrome, which occurs in fewer than one in 100,000 births and almost exclusively affects males. Boys with the disorder are born without functioning white blood cells — a type of immune cell — which makes the body more susceptible to infections and causes spontaneous bleeding that can be life threatening. Within the first few months of life, babies with the disorder can develop eczema, severe nosebleeds, bloody diarrhea, and recurrent bacterial infections.
Both of Pinarowicz’s brothers passed away from complications of the disease. One died as a toddler, before she was born, and her other brother died at age 18, when Pinarowicz was a teenager.
“My whole childhood was completely traumatizing and chaotic,” she says. Her older brother’s life was punctuated by health emergencies. “He would end up in the hospital in the middle of the night, and we wouldn’t know if he was going to live or die.”
Wiskott-Aldrich syndrome is caused by a mutation in the WAS gene on the X chromosome. Because women have two X chromosomes, they can have a mutation in one copy of the gene and not have the disease — what’s known as a carrier. Even though she didn’t have the disease herself, Pinarowicz worried that she could pass on the mutation to her future children. So, when she was 23, she got tested to see if she was a carrier. The results came back positive.
Pinarowicz thought it would be too risky to have her own children. As a carrier of an X-linked recessive condition, the chance of having a boy with Wiskott-Aldrich is 50 percent. But years later, after meeting her husband, Pinarowicz learned about a powerful technology that would allow her to have children while being certain that she would not pass on the mutation that had killed her brothers and plagued her family.
The technique is called preimplantation genetic testing (PGT). By using PGT together with in-vitro fertilization, Pinarowicz and her husband had a healthy son in May…