Scale, Toll of Gene Birth Defects Vast, Study Finds

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January 31, 2006

Scale, Toll of Gene Birth Defects Vast, Study Finds

http://www.latimes.com/news/nationworld/world/la-sci-

birthdefect31jan31,1,3249564.story

Most cases are preventable, but millions of children die early or are

disabled. Testing and nutrition could help poor nations.

By H. Maugh II, Times Staff Writer

Nearly 8 million children each year are born with genetic birth

defects, and fully 70% of them could be prevented or mitigated,

according to the first worldwide study commissioned by the March of

Dimes.

With most receiving no treatment, at least 3.3 million of the

children die before the age of 5 and 3.2 million are disabled for

life, said the study, which was released Monday.

" Our report identifies for the first time the severe and previously

hidden global toll of birth defects, " said Dr. L. Howse,

president of the March of Dimes, based in White Plains, N.Y. " This is

a serious, vastly unappreciated and underfunded public health

problem. "

The incidence ranges from a high of 82 defects per 1,000 births in

Sudan to a low of 39.7 per 1,000 in France. More than 94% of birth

defects and deaths occur in middle- and low-income countries, said

Dr. P. Howson of the March of Dimes, a coauthor of the

report.

The authors believe that hundreds of thousands more birth defects

occur because of environmental factors, such as congenital rubella

and syphilis, iodine deficiency and fetal alcohol syndrome. But

Howson said meager data were available to document the incidence of

those problems.

Fetal alcohol syndrome, in particular, " is a huge problem, but there

are countries that don't monitor it or recognize it, " said Dr. Arnold

Christianson of the University of the Witwatersrand in Johannesburg,

South Africa, another coauthor.

Five common birth defects accounted for about 26% of the total in

2001, the most recent year for which data were available. They

included congenital heart defects (1 million cases); neural tube

defects, such as spina bifida (324,000 cases); the hemoglobin

disorders thalassemia and sickle cell disease (308,000 cases); Down

syndrome (217,000 cases); and glucose-6-phosphate dehydrogenase

deficiency (177,000 cases).

" This is an extraordinary toll, " Howson said. " People are going to

ask, 'Why isn't more being done to address this problem?' "

Among the reasons for the higher incidence of birth defects in

developing countries, the report concluded, are the increasing number

of older women having babies, the higher frequency of marriages

between blood relatives and poor nutrition among pregnant women.

A large fraction of the at-risk population also lives in the " malaria

belt, " where that disease is endemic. Many people there carry a gene

for an inherited disease, such as sickle cell, thalassemia, or G6PD

deficiency, that protects against malaria but can produce birth

defects when carriers mate.

The incidence of birth defects and disability can be sharply reduced

in developing countries, the report concluded.

" Experience from high-income countries shows that overall mortality

and disability from birth defects can be reduced by up to 70% if the

recommendations in this report were broadly implemented, "

Christianson said.

Some solutions are relatively simple, such as adding folic acid and

iodine to the food supply and including a rubella shot in vaccination

programs.

Folic acid supplementation in enriched flour, for example, costs

about a penny per person per year. In 2000, Chile began adding folic

acid to flour and saw a 40% drop in neural tube defects.

Genetic testing for defects such as phenylketonuria (a digestive

disorder) and thalassemia can be relatively cheap — as little as $5

per test.

The report noted that Iran began testing engaged couples for the

thalassemia gene in 1997 because of the growing cost of care. By

2001, 10,298 at-risk couples had been identified and counseled, and

thalassemia births had dropped 70%.

Many birth defects, including some heart defects, clubfoot and cleft

lip and palate, can be corrected by surgery. Too often, however,

newborns are discharged from the hospital or birthing center without

anyone being aware of their problems.

" No child should leave a hospital or clinic who has not been examined

by a provider who has been trained to recognize and diagnose birth

defects, " Howson said. " There are effective ways to care for a lot of

these birth defects and save [the children] from unnecessary death

and disability. "