SIDS and the serotonin transporter gene

(1/24/03)

Dear Friends,

A number of articles hit the news the past few of days regarding SIDS and the serotonin transporter gene. The news refers to a study published in the American Journal of Medical Genetics, January 17, 2003, entitled, "Sudden infant death syndrome: Association with a promoter polymorphism of the serotonin transporter gene," led by Debra E. Weese-Mayer of the Department of Pediatrics, Rush Children's Hospital at Rush-Presbyterian-St. Luke's Medical Center, Rush University, Chicago, Illinois. The public has been on an information roller coaster, the result of an explosion of media reports. We need to help people separate myth from fact and risk factor from cause. We will post information as it becomes available to us.

Please keep the following in mind:

- Other studies made similar claims since 1985.

- The study's authors do not claim to have determined the cause of SIDS.

- The study's authors state that the results indicate a relationship between SIDS and the L allele of the 5-HTT gene in African Americans and Caucasians, and if confirmed, will provide an important tool for identifying at-risk individuals and estimating the risk of recurrence..

- When it comes to media coverage of SIDS, we often feel a sense of frustration in being confronted with misleading headlines, announcements of so-called breakthroughs and statements taken out of context.

- Please read the article, "Mass Media's" Role in SIDS Education, at <http://sids-network.org/media.htm>.

- You can search MEDLINE for serotonin, SIDS, and  5-HTT information.

We are currently gathering more information about this specific research and will keep you updated.

You can read the abstract of the study here.

Thanks!

Chuck Mihalko
Executive Manager
SIDS Network

Sudden infant death syndrome: Association with a promoter polymorphism of the serotonin transporter gene
American Journal of Medical Genetics
Articles Available Online in Advance of Print
American Journal of Medical Genetics Part A
Published Online: 16 Jan 2003

Abstract

January 27, 2003

The paper by Weese-Mayer and colleagues is a very exciting and important paper, and a complex one at that. Hannah Kinney could do a terrific job of putting this into lay language, but here is a quick and simplistic try:

1. Hannah Kinney and colleagues have shown a reduction of serotonin binding in brainstem areas important to cardio respiratory function and circadian rhythm in SIDS cases compared to controls,

2. Abnormalities in the gene that influences serotonin transporter protein has been demonstrated more often in Japanese SIDS cases than controls.

3. Therefore, Weese-Mayer and colleagues evaluated brain tissues from 43 African-American and 44 white SIDS cases and 87 gender/ethnicity matched controls to compare the frequency of the gene abnormalities in these two groups, and

4. Found that there were statistically significant positive associations of the gene abnormalities with the SIDS cases compared to the controls that were somewhat similar to the findings in the Japanese cases, and

5. If their results are confirmed, then it may be possible to have a test that helps identify infants at risk for SIDS and estimating the risk of recurrence in a subsequent sibling,

6. The authors point out that their paper has weaknesses including;

a. There was little known about the SIDS cases such as smoke exposure or other SIDS cases in these families, and

b. The sample sizes in both groups were limited and did not include babies other than white or African American.

---Henry Krous, MD
hkrous@health.ucsd.edu