New Clues: Whole-Gene Scan Analyzes Mystery Illnesses

A new kind of genetic test that analyzes all of a persons genes can provide a diagnosis about a quarter of the time for patients whose conditions have baffled doctors, scientists reported Saturday. And for young children with mysterious developmental delays, the test gives a diagnosis more than 40 percent of the time.

The test is called whole-exome sequencing, and it looks at all 20,000 or so genes in the human body. Its not a whole genome sequence because it leaves out DNA thats not classified as a gene. But such tests provide a good map of the so-called protein coding sequences.

It was a relief for Audrey Lapidus of Los Angeles, whose baby son Calvin seemed just fine at first. But at 6 months, an osteopath suggested genetic testing. She said he had some very interesting facial features, Lapidus told NBC News. Other pediatricians rejected the notion.

But then he just wasnt hitting the milestones, she said. He wasnt sitting up or rolling over.

Deep down, I knew something was wrong."

Still, pediatricians and friends alike reassured her. A basic genetic panel came back clear.

Everyone wants to tell you about their nephew who didnt walk until he was 2 and he graduated from Harvard, Lapidus said. I was holding on to those stories.

At the same time, she continued to visit geneticists and neurologists. Deep down, I knew something was wrong, she said.

Calvin became the first child at UCLA to get a whole-exome genetic test at UCLA, in 2012. When it came back, it showed Calvin had Pitt-Hopkins Syndrome, a rare genetic disorder affecting only 250 children worldwide.

Its caused by a single mutation on one gene found on chromosome 18. It causes developmental delays, seizures and, as Calvins osteopath suspected, distinctive facial features, such as thin eyebrows and sunken eyes. Children often never learn to speak or walk without help.

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New Clues: Whole-Gene Scan Analyzes Mystery Illnesses