Years-Long Search Unlocks Deadly Genetic Disease

By Amanda Gardner
HealthDay Reporter
Thursday, January 10, 2008; 1:00 PM

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THURSDAY, Jan. 10 (HealthDay News) -- Ann Messer knew something was wrong while she was still pregnant with her second child. Her baby didn't move, except sometimes to roll over to one side of her body, leaving her stomach flat.

Her fears were confirmed when her son, Andrew, was born. "He had a very weak cry, very little muscle tone, he had contractures in his knee joints," Messer recalled.

The doctors diagnosed congenital muscular atrophy. Andrew died at 5 months of age, in 1985.

Two months later, a first cousin of Messer's, living in Evansville, Ind., gave birth to a baby boy with similar characteristics. That baby died at 10 months of age. "My mother saw him one time and said he was floppy, very limp, didn't move," Messer recalled.

And unbeknownst to Messer at the time, yet another cousin, in a third branch of the family, this one living in New Orleans, had earlier given birth to two baby boys with the same condition. One died at 18 months and one lived to 18 years, although he needed a feeding tube and was confined to a wheelchair for all his short life.

In all, four baby boys with the same condition were born in roughly a five-year span. They all died.

Several years later, doctors were able to give the disease a more specific name: autosomal recessive spinal muscular atrophy (SMA). SMA is a neurodegenerative disorder occurring in children that involves severely weakened muscles and usually results in death within two years, often because muscles of the respiratory system can no longer support breathing. The X-linked form of the disease is passed unsuspectingly by healthy mothers to their sons.

SMA made sense to Messer and her family, but they were baffled by the autosomal part of the diagnosis.

"I'm not a genetics person, but I know that autosomal recessive means that both mothers and fathers have to be carriers [of the gene that causes the disease]," Messer said. "We started scratching our heads. What are the odds that all of us would have married somebody with the same recessive gene and our two mothers and our grandmother? I don't calculate odds very well, but I can tell that that's just a staggering amount."