Featured Research

from universities, journals, and other organizations

Age Not Only Factor In Down Syndrome: Number And Age Of Existing Siblings Are Also Influential

Date:
October 16, 2006
Source:
Springer
Summary:
Whether or not a pregnant woman will give birth to a child with Down Syndrome is not simply a matter of how old she is. Although it is a fact that as women get older, they are more likely to have a child with Down Syndrome, other factors also play a role. The research is published in Springer's journal Naturwissenschaften this week.

Whether or not a pregnant woman will give birth to a child with Down Syndrome is not simply a matter of how old she is.  Although it is a fact that as women get older, they are more likely to have a child with Down Syndrome, other factors also play a role.  According to Markus Neuhäuser and Sven Krackow, from the Institute of Medical Informatics, Biometry and Epidemiology at University Hospital Essen, in Germany, the risk of a child being born with Down Syndrome is also dependent on how many existing siblings the child has and how big the gap is between the child and his immediate preceding sibling.  The research is published in Springer’s journal Naturwissenschaften this week.

Neuhäuser and Krackow reviewed and analysed data from 1953 and 1972 (before abortion was widespread).  They found that other factors, besides the mother’s increasing age, were linked to the number of Down Syndrome cases.   Down Syndrome rates were significantly higher in older mothers in their first pregnancy than in older mothers who had already had children.  Only late first pregnancies were more likely to produce a Down Syndrome baby, not late second or third pregnancies.   In addition, the larger the gap between pregnancies, the higher the rates of Down Syndrome.

Down Syndrome is the result of the genetic abnormality trisomy 21.  Trisomy has been the focus of extensive medical research but the exact mechanism is still not understood.  One feature common to most trisomies is an increase in frequency of trisomic pregnancies with increasing maternal age.  There is strong evidence for uterine selection against genetically disadvantaged embryos.  However, as women approach the menopause and the risk of future infertility increases, this selection, or filtering stringency, is expected to relax.

Neuhäuser and Krackow’s paper provides evidence that older mothers, who give birth to children with Down Syndrome, have a relaxed stringency of quality control of embryos (or relaxed filtering stringency), which increases the probability that these women will bring children with developmental defects to full term.  They believe that this relaxed filtering stringency is an adaptive maternal response and it might explain why the rate of Down Syndrome accelerates with increasing maternal age.

These findings have important implications for the prevention of abnormal fetal development.  The authors conclude that “clearly, identification of the relaxation control mechanisms and therapeutic restoration of a stringent screen holds promise not only for Down Syndrome.”

1.  Neuhäuser M & Krackow S (2006).  Adaptive-filtering of trisomy 21: risk of Down Syndrome depends on family size and age of previous child.  (Naturwissenschaften, DOI 10.1007/s00114-006-0165-3)


Story Source:

The above story is based on materials provided by Springer. Note: Materials may be edited for content and length.


Cite This Page:

Springer. "Age Not Only Factor In Down Syndrome: Number And Age Of Existing Siblings Are Also Influential." ScienceDaily. ScienceDaily, 16 October 2006. <www.sciencedaily.com/releases/2006/10/061012184355.htm>.
Springer. (2006, October 16). Age Not Only Factor In Down Syndrome: Number And Age Of Existing Siblings Are Also Influential. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2006/10/061012184355.htm
Springer. "Age Not Only Factor In Down Syndrome: Number And Age Of Existing Siblings Are Also Influential." ScienceDaily. www.sciencedaily.com/releases/2006/10/061012184355.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) — Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) — The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) — Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) — New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins