ID or FRAT boy/girl twins

Okay so someone explain to me how b/g twins can be identical. Mine are very different but I heard some comments about the same blood type, same hair and eye color. Mine ARE fraternal but they have the same blood type, same hair and eye color. When I say they are not identical because they are b/g I get corrected everytime but no one can explain how that works.

Just to share, here are mine

 

Umm, really? Boy parts and girl parts. So perhaps when explaining you should tell people that while they share identical facial features their "parts" are very different. I am sorry, I don't mean to make light of it, just don't know how else to say it without being blunt.

 

they are very cute! and getting so big!

 

I found this on wikipedia.

QUOTE
Monozygotic twins are genetically identical (unless there has been a mutation in development) and they are always the same sex. On rare occasions, monozygotic twins may express different phenotypes, normally due to an environmental factor or the deactivation of different X chromosomes in monozygotic female twins, and in some extremely rare cases, due to aneuploidy, twins may express different sexual phenotypes, normally due to an XXY Klinefelter's syndrome zygote splitting unevenly


So, if boy/girl twins are monozygotic, they are not genetically normal, and I believe this results in a girl with Turner's syndrome and a boy. But don't quote me on that.

If you have boy/girl twins, they are dizygotic aka fraternal!

 

QUOTE(Mum2TwinBoys @ Aug 15 2008, 09:17 PM) [snapback]932587[/snapback]
Umm, really? Boy parts and girl parts. So perhaps when explaining you should tell people that while they share identical facial features their "parts" are very different. I am sorry, I don't mean to make light of it, just don't know how else to say it without being blunt.



Believe me I do say that. When they say are they identical? I say no then they say well they look exactly alike (ahem, you just asked if they were and now you are saying they are but I digress) I say no they are not identical, not below the waist anyway! I then laugh and move on.

Several people have said it is possible and that I shouldn't always say that they aren't just because of gender. I say those people didn't take science classes or something. I thought they would have to be a hermaphodite or something so I was just curious.

 

Identical twins that are boy/girl are extremely rare and the girl will have serious problems, one being Turner Syndrome. It is VERY rare situation. Also, di-zygotic does not always mean fraternal. My boys were di/di and are identical.

I think the problem is that people use the word identical to mean "they just look alike." They don't know what identical really means. It means they have virtually the same DNA markers. One is naturally a clone of the other. People sometimes think boy/girl can be identical because they happen to look alike. They just are ignorant of the true meaning of identical.

I once had a nurse argue with me that her neiece and nephew were identical twins. "Well they look an awful lot alike, that means identical" is what she kept saying. She just had no idea what identical really means.

 

I think mine look a lot alike. I have gotten so many comments lately that they look so much alike. One mom even said to her b/g twins "see that is what real twins look like, they look alike". Real twins? WTF as compared to fake twins? I wanted to slap her!

 

I've heard about the b/g identical twin thing to and saw a little video on it posted on here before. It was a link to National Geographic, but I can't find it anywhere.

Erica

 

They are really cute!!!! Who tells you they are identical????

Jen

 

identical = same sperm and egg threfore must be same sex. each sperm has either an x or y chromosome and each egg has only an x. when the egg is fertilized you end up with an embryo that is either xx (female) or xy (male) and then it splits. so the resulting twins are either xx or xy. it is impssible to have b/g identical twins. hope that helps.

 

QUOTE(Cristina @ Aug 15 2008, 09:06 PM) [snapback]932689[/snapback]
Identical twins that are boy/girl are extremely rare and the girl will have serious problems, one being Turner Syndrome. It is VERY rare situation. Also, di-zygotic does not always mean fraternal. My boys were di/di and are identical.


Dizygotic means fraternal (that means two eggs). Dizygotic twins are always di/di [dichorionic diamniotic] whereas monozygotic twins (one egg) can be di/di, mono/di [monochorionic diamniotic] or mono/mono [monochorionic monoamniotic].

QUOTE
Mine are very different but I heard some comments about the same blood type, same hair and eye color. Mine ARE fraternal but they have the same blood type, same hair and eye color.


My brother and I both have blond hair that become darker with age, blue/green (+grey for me) eyes and the same boold type. Both my parents have blue/green or blue/grey eyes and blond hair that become darker with age. My mother is B- (B/O) and my father is A+ (A/O) so we could have had different bood types. I can assure you we are not identical because I don't have the Turner Syndrome but people keep saying "are you identical twins ?"... They just don't pay attention to the facial figures ! I think your kids are pretty easy to tell appart evn though they "look alike" (and I can tell you that my brother and I were "look alike" when we were babies)


QUOTE
it is impssible to have b/g identical twins

It is possible. When the egg slip up and becomes two eggs, some "mutations" can happen as the loss of the Y chromosome... So the baby will be a girl with only one X instead of XX. Or she can be XX/Y

 

Again, people are DUMB! And your babies are ADORABLE!! They have gotten SO big!!!

 

Your babies are beautiful, they do not look identicle though to me.

 

QUOTE(Zibeline @ Aug 16 2008, 03:45 AM) [snapback]932903[/snapback]
They just don't pay attention to the facial figures !


I wanted to say facial features... sorry ! Is there a way to edit messages ?

 

My Twins looked EXACTLY alike when they were born. I still gett he questions "are they ID" I think its funny bc DS has a shaved head and DD have long hair.. :unknw:

 

QUOTE(Cristina @ Aug 15 2008, 08:06 PM) [snapback]932689[/snapback]
Identical twins that are boy/girl are extremely rare and the girl will have serious problems, one being Turner Syndrome. It is VERY rare situation.


Very rare is an understatement. I heard about this and looked up some info on it. If I recall there's only been like 2 reported cases of b/g ID twins in the world. I just did a little experiment. I asked my DH (who hasn't gone out of his way to learn about twins.) if b/g/ twins can be ID. He said "Sure, they can look alike. I've seen it." Just proving the pp's point that some people define ID as "looking alike" and not as genetic equals.

I would just smile and nod and let people live in their own little world. Who wants to stand around in the grocery store or at the park giving free genetic lessons to people who won't listen anyway?

 

I think if someone tried to "correct" me and say b/g can be id, I would ask them to explain how.

 

Found this today:

A pregnancy of two or more fetuses is called a multiple pregnancy. Multiple fetuses can be the same (identical) or different (fraternal).

See a picture of identical and fraternal twins in the womb (uterus).

Identical twins or triplets come from a single egg that has been fertilized by one sperm. For unknown reasons, the fertilized egg splits into two or more embryos during the first stage of development. Some identical twins share the same placenta. But they usually grow within separate amniotic sacs in the uterus. In rare cases, identical twins share one amniotic sac.

Identical twins:

Are always the same sex and blood type.
Usually share the same physical features, such as skin, hair and eye color, and body build. But they do not always look exactly alike. They do not have the same fingerprints. Also, one may be right-handed while the other is left-handed.
Are thought to develop at random. They are not related to your age, race, or family history of twins.1
Fraternal twins, triplets, or more develop when two or more eggs are fertilized by separate sperm. Fraternal fetuses have separate placentas and amniotic sacs.

Fraternal multiples:

Can be either gender (male or female) and can have different blood types.
May look very different from one another, with different-colored hair and eyes. They may also look alike, as siblings often do.
Tend to run in families.
Multiples that are conceived with infertility treatment are almost always fraternal, rather than identical.

What are common causes of multiple pregnancy?
Infertility treatment. Since 1980, infertility treatment has more than doubled the U.S. twin birth rate. The rate of triplet-or-more births is now nearly 5 times higher than before infertility treatment was used.2

You are more likely to have a multiple pregnancy if you use fertility drugs or assisted reproductive technology (ART).

Fertility drugs stimulate your ovaries to release more than one egg, which can be fertilized at the same time. This may result in a multiple pregnancy.
ART is the transfer of multiple embryos directly into the uterus to increase your chances of pregnancy.3 Overall, 25% to 30% of pregnancies from ART are twins; 5% are triplets; less than 1% are quadruplets or more.1
Other causes. Certain factors increase your risk for having a multiple pregnancy.

Age older than 35.2
Race. Fraternal twins are most common among women of African descent, especially between ages 35 and 45.4 They are least common among Asian women.4
Personal history. If you have already carried fraternal twins, you have double the usual risk of having twins.1
Family history. If your family has a history of fraternal twins or triplets, you have an increased risk of multiple pregnancy. (A history on the father's side of the family does not increase your risk of multiple pregnancy.)4
Timing. You are more likely to conceive multiples soon after stopping birth control pills.4

 

just to reiterate, most people that will ask you are clueless. the woman at the checkout station at our local sams club the other day asked if mine were identical or something. not sure what she thought the other something might be. I think most people have a general idea that there are different types of twins but they aren't informed, that- and there are those that hear stories and it doesn't matter how rare the situation might be- you as the children's mother might be wrong and they might be enlightening you to some great awakening-- just like when they tell you you're feeding them wrong or disciplining wrong or dressing them wrong or whatever.

I like the identical except below the belt bit. that's funny. probably how I'd answer it, too.

good luck with all the wierdo's out there, hope you get enough nice comments to balance it out.