Top
30
Doctor insights on: How Can Identical Twins Be Very Different Sizes

Share
1

1
How can identical twins be very different sizes?

How can identical twins be very different sizes?

Identical twins: Identical twins share a placenta. It certain circumstances the amount of placental blood flow to one twin may be more than to the other twin. That effects the growth of the twins. ...Read more

2

2
Does identical twins have different sacs?

Does identical twins have different sacs?

Some do some don't: If two twins share the same sac, they're identical. (almost always works.) the pathologist who examines the placenta can tell. Identical twins can have two sacs, or one sac; if there are two sacs, there can be one or two chorions. Fraternal twins won't share chorions or sacs. ...Read more

3

3
Can identical twins have their menarche come at different times?

Can identical twins have their menarche come at different times?

Menarche: Yes. Just because they're identical genetically does not mean they'll do everything the same. Other factors contribute to puberty-timing, like weight gain. A bone-age x-ray can predict pubertal delay. ...Read more

4

4
Identical twins have the same DNA sequence, then how would you explain the different patches of sweat glands, can you explain?

Identical twins have the same DNA sequence, then how would you explain the different patches of sweat glands, can you explain?

We're complicated: The twins share the same DNA sequence but going from a fertilized egg to splitting into multiple cells to form a human can be influenced by several factors that can lead to individual differences. I found this article very helpful in answering your question.

http://multiples.about.com/od/funfacts/a/differenttwins.htm ...Read more

5

5
Are identical twins always identical?

Twins: Not necessarily. Personality-wise, there is a pair of identical twins in my practice who have different personalities. One is an extrovert and athletic in nature while the other is introverted. ...Read more

6

6
Can there be male and female identical twins?

Can there be male and female identical twins?

Identical twins: Identical twins are always the same sex. They have the same genetic endowment. Fraternal twins are siblings that were in utero together. Fraternal twins can be the same sex or the opposite sex. ...Read more

7

7
Are fraternal or identical twins more common?

Are fraternal or identical twins more common?

Yes: Fraternal twins are 3 times as frequent as identical. Fraternal twins happen when there is double ovulation and 2 eggs get fertilized. They are the type of twins that run in families. Identical twins come from 1 fertilized egg which separate in early gestation. Depending on when they separate, the babies can be in 2 distinct sac (di/di), 2 sacs within a shared sac (mono/di) or 1 sac (mono/mono). ...Read more

8

8
Does children of identical twins who marry identical twins look alike?

Does children of identical twins who marry identical twins look alike?

Not always: They would be no more likely to look alike than any other siblings. ...Read more

9

9
Is it possible identical twins can have the same gender of a child? What's the possibility?

Is it possible identical twins can have the same gender of a child? What's the possibility?

If you are asking: If two identical twins, say both are women giving birth at the same time, have a higher chance of having the same gender for their babies, then the answer is no. The probability is 50% for 1 twin mother and 50% for the other twin mother delivering both a boy, 0.5 x 0.5 = 0.25 or 25%, but adding to the same probability for a girl. So 25% both girls + 25% both boys = 50%. ...Read more

10

10
Do identical twins both develop autosomal dominant disorders?

Do identical twins both develop autosomal dominant disorders?

Yes: They occur when one fertilized egg & sperm split in to two pregnancies, so will share all features, good and bad. ...Read more

11

11
What's the difference between fraternal and identical twins genes?

What's the difference between fraternal and identical twins genes?

Different, same.: Fraternal (dizygotic) twins share 50% of their genes, just like any other siblings. Identical (monozygotic) twins typically have the same 100% dna profile, as if clones of one another. ...Read more

12

12
Could a 5 day frozen blastocyst be divided into identical twins after transfer?

Could a 5 day frozen blastocyst be divided into identical twins after transfer?

Yes: Actually this is slightly more common after day five transfer ~1%. Since the embryo is in nearly hatching or hatching, the transfer "pressure" can cause the embryo to split into identical twins. This is one of the disadvantages of day 5 transfer. Good luck. ...Read more

13

13
Do identical twins have the same fingerprint?

Do identical twins have the same fingerprint?

No: I understand that every person has unique finger prints. ...Read more

14

14
Do identical twins have the exact same DNA?

Do identical twins have the exact same DNA?

Yes: Identical twins start off with the exact same DNA. Small mutations can occur, so there might be slight differences that develop. ...Read more

15

15
Can an orgasm kill an unborn identical twin? Should orgasming be stopped due to identical twins or MoMo twins?

Can an orgasm kill an unborn identical twin?
Should orgasming be stopped due to identical twins or MoMo twins?

No, if all is normal: A fetus can die after the pregnant woman has an orgasm, but can also die before she has an orgasm. A fetus can die after the woman eats a peanut butter and jelly sandwich. All these things do happen, BUT are they related? The answer is NO, unless the woman has a problem that causes two things to be related (such as having a peanut allergy, and a life-threatening reaction after a PB&J sandwich). ...Read more

16

16
Are identical twins a product of the mother or father?

Are identical twins a product of the mother or father?

Both : A fertilized egg cell will split into two separate embryos, and grow into identical twins. A common misconception about identical twins is that the trait for having them is passed on to future generations through the mother's genes. But the truth is science doesn't know the reason why identical twins occur. At this time, we can just say that they're examples of a nine-month double miracle. ...Read more

17

17
If you have identical twins, will they both develop the same genetic/inherited disease at the same point?

If you have identical twins, will they both develop the same genetic/inherited disease at the same point?

Depends: If it's something that fully expresses itself with no modification (such as huntington's), yes. If it's going to express itself but is lifestyle-modifiable (type ii diabetes), timing will differ. The diseases for which there's a genetic component (diabetes, lupus, multiple sclerosis, many others) have only one twin affected more often than not -- you can find details. ...Read more

18

18
After healthy heart rates are identified in identical twins, what is the probability of a vanishing twin?

After healthy heart rates are identified in identical twins, what is the probability of a vanishing twin?

Fairly common: A conservative estimate of frequency is that vanishing twin syndrome occurs in 21-30% of multifetal pregnancies. More commonly identified now that first trimester ultrasound is widely used. There are no known preventive measures since the loss usually occurs because of cord implantation abnormalities. Thanks for trusting HealthTap! ...Read more

19

19
My Husband has multiple sets of fraternal twins on his side and I have identical twins on my side, is the twin gene carried on the male side or woman?

My Husband has multiple sets of fraternal twins on his side and I have identical twins on my side, is the twin gene carried on the male side or woman?

Female Side: Genetic increase for twins is due to female tending to ovulate more than one egg at a time, so trait is for fraternal twins (not identical) and carried by mother. ...Read more

20

20
Why would my pediatrician be concerned about my 15 month (13 adjusted) identical twins girl's height?

Why would my pediatrician be concerned about my 15 month (13 adjusted) identical twins girl's height?

We always watch it: Pediatricians always watch the height, weight, and head size for a baby or toddler. That's how we know if the growth is fine. Sometimes, two or three measurements are needed to get an accurate number on a squirming baby. We get concerned if a number is "off the graph" on the growth chart, or if numbers are trending too high or low for a particular child compared with her peers, sibs, or parents. ...Read more

21

21
Do identical twins have the same sexual orientation? If not, does that mean sexual orientation is not encoded in DNA?

Do identical twins have the same sexual orientation? If not, does that mean sexual orientation is not encoded in DNA?

Twin DNA: Although identical twins have the same DNA, the DNA molecule has the potential for mutation, and changing the gene's expression creating differences depending upon the gene(s) involved. Gender identity is thought to be determined by genetics as well as other factors, although an actual variation or determining factors have not been identified. ...Read more

22

22
Need doctor's help! Will identical twins be missed in 7 week ultrasound? 2013

Need doctor's help! Will identical twins be missed in 7 week ultrasound? 2013

I Hope Not!: Twins at 7 weeks should be fairly clearly visible on a transvaginal sono. As far as whether they might be identical, that is a more difficult question to answer by sono and requires careful analysis of the membranes surrounding fetuses, unless there is a single sac which would only be seen in an identical twin (rare). They can also be in 2 sacs however. ...Read more

23

23
How often can a donor egg embryo split and result in identical twins? Is it in most cases or is it rare? We will be using icsi

How often can a donor egg embryo split and result in identical twins? Is it in most cases or is it rare? We will be using icsi

1-2%: The reported risk is about 1-2%. No longer believed in general to be related to icsi. When more than 1 embryo is placed inside the risk seems to be higher for reasons which are not known. Also, the risk as far as I am aware is not higher in donor versus non donor egg. ...Read more

25

25
Can you have an identical twin but who have different eye colors from one another?

Can you have an identical twin but who have different eye colors from one another?

Yes: Albeit a weak answer.... Eye color can change during your lifetime due to a whole host i reasons. So although at birth identical twins would theoretically have the same color eyes, that may change over time. ...Read more

26

26
My aunt died from stage 4 pancreatic cancer in 03/2013. She has an identical twin sister-is she at higher risk? She had the different one than swayze

Perhaps: Only a few pancreatic cancers are thought to be hereditary. The majority occur without a family history. There are several types of pancreatic cancer and I do not know what type mr. Swayze had. ...Read more

28

28
Thyroid cancer and heredity? How much does heredity play a part in getting thyroid cancer? Is it different if the relative who had it is a cousin vs. A mother or an aunt? What about an identical twin?

Thyroid cancer and heredity? How much does heredity play a part in getting thyroid cancer? Is it different if the relative who had it is a cousin vs. A mother or an aunt? What about an identical twin?

A little bit: Authorities think about 5% of patients with thyroid cancer may have a hereditary component. We can't identify the genes yet, and go by "clusters. In general, the closer the relative, the more likely you will have thyroid cancer, assuming that this has a hereditary component. But most don't. ...Read more

29

29
Does it make the twins identical?

Does it make the twins identical?

I'm confused!: Does what make the twins identical? Please ask your question again and clarify what you wish to know. ...Read more

30

30
How do I know if I am having identical or fraternal twins?

How do I know if I am having identical or fraternal twins?

Depends: You can determine it based on ultrasound if there is only one placenta. However, often times you need to have babies tested after they are born. Even twins that "look" identical may not actually be identical. ...Read more