PHILADELPHIA
(Reuters Health) - A new test reliably detects a disease in newborns
that can be fatal, often within the first year of life, according
to findings from a statewide screening program instituted in North
Carolina.
The disease,
called MCADD--for medium-chain acyl-CoA dehydrogenase deficiency--causes
2% to 4% of cases of sudden infant death syndrome (SIDS). What's
more, it appears to be more common than phenylketonuria (PKU),
the dangerous condition every US newborn is routinely screened
for, according to Drs. Shawn E. McCandless and Joseph Meunzer
of the University of North Carolina at Chapel Hill. The findings
were presented here at the annual meeting of the American Society
of Human Genetics.
MCADD is an
inborn error of metabolism that prevents the proper digestion
of body fat stores. Whenever healthy people go without eating
for too long, their bodies naturally draw upon stored fat as fuel.
But people with MCADD are unable to digest their stored body fat,
and must fuel their bodies with recently consumed sugars and starches.
If left undetected,
MCADD will cause death in up to one third of affected children,
with another third experiencing coma or seizures that can lead
to permanent disability, McCandless said. Yet the treatment is
simple: parents are told to make sure their child eats regularly.
They are also warned to avoid obesity in their children because
dieting is difficult.
In screening
327,031 newborns in North Carolina over the past 3 years, 24 were
found to have MCADD. These babies were otherwise completely normal
at birth, and all are doing well now, the researchers reported.
This means
the screening effort detected about one MCADD baby per 10,000
white infants tested. Although MCADD is thought to be a disease
of white children, the researchers discovered one case in an African-American
baby. By contrast, PKU occurs in about one of 20,000 births, McCandless
said.
When North
Carolina began screening for MCADD 3 years ago, it was the first
state to do so, but a handful of states now offer the screening,
Meunzer added.
As with other
screening tests for newborns, only a tiny drop of blood is required.
The sample is evaluated using tandem mass spectrometry, a technology
for rapid, highly sophisticated chemical analysis. Meunzer explained
that this instrument makes widespread screening for MCADD practical.
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