To many, having a child with a birth defect called microcephaly might seem to be the end of the world. And so it did, initially, for a family near Wichita, Kan., that experienced it — twice.

But for Gwen and Scott Hartley, their two daughters, born with abnormally small heads and brains, are a source of joy.

Microcephaly recently has been linked with the virus Zika, which is causing alarm among health officials. Thousands of parents have been heartbroken in Brazil, where the mosquito-borne virus has been most active. It has the potential to spread to parts of the United States.

“My heart just goes out to those moms that are dealing with that,” Gwen Hartley said. “While I would not have chosen this for my children, and it’s definitely not something I would wish to happen, in our situation it has caused us to rise to the occasion. I think I have become a better person.”

Neither Claire nor Lola Hartley can talk. Claire has a feeding tube. The girls have other serious problems and require constant attention. Both have spinal malformations and Claire has cerebral palsy, epilepsy and cortical visual impairment.

Claire Hartley, 14, is about 3 feet tall and weighs 23 pounds. Lola, 9, is 2 feet tall and weighs 12 pounds. They have to be carried everywhere.

The Hartleys do not hide their daughters or shun attention. In fact, Gwen Hartley started a blog called The Hartley Hooligans in which she lightheartedly chronicles the daily challenges of caring for the two girls.

“I feel like you can choose to view it as a really sad thing,” said Gwen Hartley. “I can list 50 reasons why it sucks. But I can list 1,000 reasons why it’s freaking awesome. They are cool, amazing, deep spiritual beings and I am so lucky to be their mom.”

Claire and Lola are aware of their surroundings and respond to love and tenderness. Claire has little or no hand dexterity, but she doesn’t know that she cannot grasp a ball. Lola is usually grasping a small rubber chicken.

Claire is easygoing and mellow, her mother said, while Lola is a feisty diva who demands to be the center of attention.

The Hartleys’ first child, 17-year-old son Cal, was born without birth defects.

“I’m just so glad I get to experience the best of both worlds,” Gwen Hartley said, adding that some people feel sorry for her. “I say you guys have no idea. Every day I am so happy that I get to have another day with my girls.”

Babies born with severe microcephaly often do not survive long. Others live to adulthood.

The Hartleys were told that Claire would probably not live a year.

“My daughter is still here and she’s thriving and progressing and happy,” Gwen Hartley said.

Doctors believe genetics were the cause in the cases of Claire and Lola, but they have not been able to identify the gene or genes responsible.

Between two and 12 babies out of 10,000 live births in the U.S. have microcephaly, according to the Centers for Disease Control and Prevention.