Wednesday, May 4, 2016

Closer Links to the Genetics of Fraternal Twins


The chance of having fraternal twins has long been known to increase if relatives have also had the  event occur, however researchers have recently been underway to find a closer link to the explanation. The United States alone saw a 76% increase in the fraternal twin population from 1980 to 2011, and scientists want an answer.

This article explains the path scientists have taken to identify the increasing factor. They've collected and compared single nucleotide polymorphisms (SNPs) of 2000 mothers of fraternal twins to SNPs of mothers who had not had twins. Researchers narrowed the results down to find two SNPs that increase a woman's likelihood of having fraternal twins by about 30%!

One of the SNPs is known to cause an increase in the hormone involved in the production of follicles, which are the sites within the ovaries that house and mature the eggs before they are released from the ovary. If the levels of this hormone is too high, the mother has an increased chance of releasing multiple eggs.

The second SNP is a bit more complicated. This one in particular is a gene that alters the way molecules signal to each other. This gene in turn, called SMAD3, has an affect on the way that the ovaries respond to the hormone coded by the other SNP. This same gene has also been linked to osteoarthritis. Scientists are planning to conduct further research on how mothers react differently due to the SMAD3 gene. These results presented were only the first step.

It's really awesome that this group of scientists have made such progress on identifying the genetic components behind having fraternal twins. This is the closest that scientists have yet to come in relation to this subject matter. This is not exactly the most critical research to be done, as there usually aren't complications or anything wrong with birthing fraternal twins. However its still always great to hear about the evolution of genetic findings in all aspects of life.

2 comments:

  1. Wow I thought that Fraternal twins were just a result of two eggs being fertilized and was independent of genetics. Maybe these SNPs are caused by environmental factors that weren't present 40 years ago which may explain why there has been such a large increase in the number of fraternal twins.

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  2. Wow I thought that Fraternal twins were just a result of two eggs being fertilized and was independent of genetics. Maybe these SNPs are caused by environmental factors that weren't present 40 years ago which may explain why there has been such a large increase in the number of fraternal twins.

    ReplyDelete