Question about identical twins?

Question

Just found out we are expecting identical twins. Can I have a boy and girl or are they always the same sex?

I assumed that they would be of same sex but have heard of mixed sets once or twice before so I was just checking. i know identical is from the same egg and from same sprem but just wanted to be sure.

Answer 1

Identical twins result from one blastocyte splitting into two. They are clones of each other and share the same DNA, so they are always the same sex. They may not physically look exactly alike, but most likely will. Fraternal twins result from the woman releasing two eggs at once and both being fertilized. These twins can be boy and girl and do not have the same DNA. They are as alike as any other siblings. I read somewhere that having fraternal twins was hereditary, but identical twins were not. It makes sense though, if you think about it. Anyway, congrats on twins! Good Luck and start getting some rest now!

Answer 2

Identical twins are ALWAYS (99.9%) the same sex because the fact that they have an exact copy of genetic material makes it very unlikely, if not impossible to have a set of identical twins to be a different sex. The only reported cases that I've read where such incidence occurred, is when one identical twin boy developed an abnormality (losing a Y chromosome) resulting in him developing into a female after the last stages of fetal development. This caused him to be sexually undeveloped and possibly sterile. I don't know for sure if it can happen vice versa (a female turning into a male) but that sort of case was extremely rare, and the fact that identical twins are a rare occurrence, makes that possibility of the genetic mutation to be greatly less common.

I found a link about the subject. If you scroll down, you will see where it explains the condition I described above. It's called Turner's Syndrome, if you are interested.

http://multiples.about.com/od/funfacts/a/boygirlident.htm

One last thing, the reason why identical twins have the same DNA is because they are a result of a split from the same zygote, causing them to have the exact DNA. If identical twins were to have two different sets of chromosomes (XX-female) or (XY-male), their DNA makeup would NOT be identical.

Answer 3

Identical Twins come from 1 egg and 1 sperm that splits resulting in 2 children that look "Identical", and have the same DNA & Blood Type... They are always the same sex and are often mistaken for each other while growing up... Although most identical twins have very different personalities...

Fraternal Twins come from 2 eggs and 2 sperm and are completely seperate individuals, they are similar to any other set of siblings except they have shared a womb, they can be same sex or opposite sex however they will have their own DNA & Blood Type and may or may not look alike...

Have fun with your twins : )

Answer 4

You definitely have pregnancy brain (X2). LOL Just teasing a little, because if you think about that question for a minute you will realize it is a bit silly.

Identical twins are ALWAYS the same gender. They can not be identical if they are opposite genders, as one will have a penis and the other a vagina!

Fraternal twins can be two girls, two boys, or one of each. But identical twins will ALWAYS be either two girls or two boys.

I have a friend with twins-a boy and a girl. She tells people that ask if they are identical that there is about "this much" difference, and holds her fingers up like she is measuring something an inch long. Most of them get it after a few seconds of confusion.

Congratulations on the twins! How exciting!

Answer 5

Identical twins will always be the same gender and unless there are some kinds of problems with the fetus/babies they will both be born with same same sexual organs. There is a small chance that something could go wrong but it is very unlikely. Also just because they are the same gender and even identical does not mean they will be the same. They will have different personalities and can be very different people.
Also being of the same gender does not mean being of the same sex. Gender is a genetic term meaning having XX of XY chromosomes, usually expressed by females or males. A person's sex is determined by how a person feels about who they are, a person can be genitally female or male but have the sex of the opposite. A person can also be genetically one gender but because of some problem have some or all of the sexual organs of the other gender.
This can be a very complicated question but the simple answer is that all identical twins are going to be either boys or girls but not both.

Answer 6

Science has now proven that though opposite sex twins are possible, they are highly rare, and involve genetic abnormalities and birth defects in the female twin. The chain of events that leads to boy/girl identical twins begins with the fertilization of one egg by one sperm. This fertilized egg then splits into what will become two separate babies, both male. During the dividing process, however, one of the babies loses half of his genetic code (the "Y" portion of the "XY" genetic code that makes the child male) and becomes a girl by default. However, most girls have two X genes (XX) and this girl only has one (X__), which means she will suffer from Turner's Syndrome. Turner's Syndrome occurs in about 1 in 2,000 births, and its presence doesn't automatically mean that the woman affected by the syndrome was a twin, as it occurs in singleton pregnancies as well. Girls with Turner's Syndrome experience ovarian failure 90% of the time, and also may show physical signs of the syndrome, such as thick skin around the neck or heart problems. For more information on Turner's Syndrome, see the link at the end of the article.

While it is possible that boy/girl identical twins occur more frequently than they have been currently documented, it is unlikely, if not impossible, that boy/girl identical twins with no genetic abnormalities to be conceived and born, at least in our species. The reality of the situation is that 99.99% of opposite sex twins are fraternal, because the presence of both an XY and an XX genetic code requires the fertilization of each egg by a different sperm. If parents or twins have any doubt about whether or not twins are identical or fraternal, it is fairly easy to obtain DNA tests, from a doctor or over the internet, to clear up any doubt.

http://www.bellaonline.com/articles/art1291.asp/zzz

Answer 7

Identical twins will always be the same sex. Two girls/two boys. Identical meaning that they have the exact same genetic makeup. A male and female cannot have the same genetic makeup.

Answer 8

No, and right this is why. Intuitively, you are able to already parent why it does no longer paintings as you think of because of the fact a similar father and a similar mom don't have indentical babies. replace the father together with his same twin and the mummy along with her same twin, and you're dealing with the situation of two babies from a similar parents having a similar point of kinship. in case you assume that the father has Aa chromosome, and the mummy has Bb, then the babies must be Ab, AB, aB or ab. Multiply for all 23 pairs of chromosomes. At maximum, cousins of same twin parents may be as close as brothers and sisters, not greater.

Answer 9

Congrats! Im having twins too!! Identical is always same gender and fraternal i think is mixed genders and or same gender but dont look alike

Answer 10

identical twins will be the same sex always