Telling IDs apart....for the science nerds out there:)

raraavis28

The posts below about ID/Frat twins reminded me of this. My boys were mono/di so they are, by definition, identical, but are pretty easy to tell apart. Most of those differences are environmental of course.....like L is 2 1/2 lbs bigger than N and his hair is still thicker. However, N was born with a hypospadias (an issue w/ his boy part) that he will need surgery for at 6 months (poor baby) whereas L doesn't. Anyway, it made me wonder why, if they have the same genetic code, one would have this condition and the other wouldn't. So my sister, who is getting her PhD in biochemical engineering, sent me this article, which I found interesting: https://www.pnas.org/content/110/9/3209.full

Long story short, even if two people have the same genetic code, those genes can be expressed ("turned on or off") differently as a result of "epigenetic regulation"...which is when different chemical "flags" are copied when the DNA replicates itself. So that can explain why some ID twins do look exactly alike but others can be easier to tell apart, or develop different conditions etc.

Anyway, I can't explain much beyond that b/c I'm not a scientist by any stretch of the imagination, but I thought I'd pass it along b/c there's never too much to learn about multiples....and b/c I'm a nerd and think this stuff is cool.

E&RMommy

Yup - same genes does not equal same gene expression.

Sunglow28

I love this explanation - its great!

DFTBA!

https://www.youtube.com/watch?v=kp1bZEUgqVI

RobinR91

This stuff IS so cool! I've been reading up on eye color. I have mono/tri triplets, identical. They all had blue eyes to start with, and at 6 mo actual, 4 mo adjusted 2 of the girls eye color is changing into the grey/green/sometimes brown color, where th

edb2002

I am a scientist...this is GREAT! Thanks

I'm 31 weeks along with our ID girls, and can't wait to pass this on to my engineer husband, we're both geeks

Mrs. Alice

Cool!  I've heard of this before.  I have ID too.  I attribute some of the differences in their appearance from their situation in utero (TTTS and SIUGR).  One of them has a heart defect and the other doesn't which I always thought was

royalcrown1

This is super interesting!  I always wondered how one of my twins could have straight hair and one could have curly!  For some reason, it made sense that one has a heart defect and one does not and one has a birthmark and one does not, but the c

Eko14

Thank you for this! Our ID girls are only 3 weeks old and I'm already tired of explaing to people why/how they look different and we can tell them apart. This mkes it easy to explain! thankyoux2