The Machin boys are identical twins, but Harry was born with a rare disfigurement: his left eye, ear and nostril never fully developed.
Now that they are 7, Harry's face makes no difference to his twin Oliver, but their mother struggled for two years to love them equally.
"When I cuddled him for the first time, waves of terror swept over me," said Charlene Machin, 33, of Staffordshire in Britain. "How could I possibly love this little boy when he looked like this?"
"People assume that maternal instinct kicks in as soon as you hold your child for the first time -- but mine didn't," she told the Daily Mail newspaper. "I just couldn't love my son when he looked like this. Instead I just felt grief -- grief for a life that I felt had been taken from me, a normal life that should have been Harry's."
ABCNews.com talked to Machin's husband, Mark Machin, who did not want to participate in an interview. He said his wife was out of the country.
Today, her bond with Harry is loving and strong. But Machin's initial response, then her adjustment, illustrate the ways in which parents deal with the surprise of having a child who is disfigured. Advocates say that honest stories like theirs help others to accept the disabled.
"Being surrounded or having contact with people with disabilities could have made the transition easier her," said Lawrence Carter-Long, spokesman for the National Council on Disability. "Part of the problem is [the disabled] are segregated, if not by institutions, then by attitudes. We don't see them in the work place or in school, so the fears and the worries are more pronounced. It's not an issue of malice, but of proximity."
Disability can mean anything from a genetic disorder like Harry Machin's to aging parents or injured soldiers who return from wars in Afghanistan and Iraq. And anyone, in an instant, can face paralysis after an accident, according to Carter-Long: "Superman falls off a horse and joins the club."
Both Kevin Irvine and his wife Karen Tamley, who live in Chicago, are disabled and have an adopted daughter with a severe facial disfigurement.
"There is no typical way to respond when you discover that someone close to you has a disability, especially something significant," said Irvine, 43.
"People on the outside shouldn't be judgmental," he said. "Unless they are going through that, they can't understand."
"The thing that is heartening, is to see that most people, at some point, realize that living with someone with a disability is different than the way you may have expected, but it's rich and fulfilling," said Irvine. "There's love -- ultimately, it is your child.
Dominika has Apert syndrome, a genetic disease characterized by facial malformations, fused fingers and toes, and a skull whose plates bond prematurely so the brain has no room to grow.
Tamley, 46, is commissioner of the mayor's office for people with disabilities and Irvine, who previously worked in advocacy, is a stay-at-home father.
He was born with hemophilia and in high school acquired HIV and Hepatitis C from blood transfusions. Tamley uses a wheelchair because she has a rare disorder of the lower spine.
Because of their disabilities, the couple decided to adopt. They worked with an American agency because they feared an international agency might not accept parents with health conditions or might "change the rules" mid-way through the process.
"We weren't looking to adopt a child with disabilities," said Irvine. "But we had no preconditions. Just like anyone else, we wanted to be parents."