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Twins' birth records

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Re: Twins' birth records

Postby AdrianB38 » Sun Aug 11, 2019 3:51 pm

Robbie J N wrote:... Do any certificates ever indicate if twins are identical or not. ...

Bear in mind that many officials will tend to follow the rule that "If it's not required then it's forbidden" - I've never heard of such a requirement nor seen evidence of it. (Apologies to those registrars who are members of this forum and would never be so pedantic! ;) )

I think though that the point would be - at the time of registration, how could anyone tell if twins were identical? Indeed, what does "identical" mean in this context? There is a DNA related definition but that obviously wouldn't have applied in the 1800s. And in my class at junior school, there were two sets of twins - I could easily tell the girls apart but my mother couldn't, while I could usually tell the boys apart until they went to different secondary schools when I got out of the habit of telling them apart, so couldn't... Not sure if they were identical or not!
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Re: Twins' birth records

Postby Robbie J N » Sun Aug 11, 2019 4:26 pm

Thanks to Guy for that reminder.
I have not followed through with all the siblings at each generation yet, all I have is their (approximate) years of birth, based on Christening records. The births in 1767, possibly, and certainly 1747 would really be pushing it to still be alive in the 1841 census. Not to mention the rounding off of ages on that particular census. (I know it was supposed to be rounded DOWN only, but this proves it could be both up and down - Source - ‘Tracing Your Ancestors Using The Census’, page 44. For those who want to nitpick!)

Regarding whether or not twins were identical or not, identical twins share a single placenta, whereas un-identical twins have one each. It has been a while since I studied this at school, and there are probably some weird exceptions, but I think that is generally the way it works. (I had a strange science teacher at high school who said he kept his wife's placenta in his fridge or freezer, I forget which. That was weird!) Being the sibling of twins growing up, certain bits of information stick in my mind.

Thanks again everyone.
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Re: Twins' birth records

Postby AntonyM » Mon Aug 12, 2019 7:03 am

In England/Wales there is no GRO instruction about the order in which multiple (live) births should be registered, other than each should have the time of birth shown. I doubt there ever has been any such rule.

As a registrar I think I always registered the elder child first, just because it seemed the obvious way to do it, but that can't automatically be assumed to be the same in every case.
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Re: Twins' birth records

Postby ksouthall » Mon Aug 12, 2019 9:34 am

Robbie J N wrote:Regarding whether or not twins were identical or not, identical twins share a single placenta, whereas fraternal twins have one each.


Just a note of caution - sometimes the placentas can fuse together and appear to be a single placenta, so fraternal same sex twins could be mistaken for identical twins.

My mum is a twin. She was born 6 weeks early and the doctor/midwife didn't realise she was one of twins until during the birth. My mum weighed about 2 lbs when she was born and it was the middle of a cold March in 1939. As they thought she wouldn't survive, they allegedly wrapped her in a blanket and put her in a box under the bed - according to my mum. They then got on with helping my aunt to be born. She arrived about half an hour later, weighing about 3 lbs.

Although my mum and aunt looked and sounded identical growing up, there was never any proof that they were identical twins. I think in the rush during the birth, the midwife may not have checked the placenta at the time or, if she did, may not have passed that information on to my gran.

A few years ago my aunt took an Ancestry DNA test. I took one a year or two later and, when I got the results through, the match to my aunt came up as a Parent-Child relationship so it appears that they are identical twins after all. Their older sister had also taken a DNA test and came up as a Close Family Member.
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Re: Twins' birth records

Postby Robbie J N » Mon Aug 12, 2019 3:31 pm

If you have an ancestor who was an identical twin and you do a DNA test, then if the other identical twin has descendants that are on the DNA database too, then it would show you to be more closely related than you are, if you see what I mean. Cousins who have parents that are identical twins would be the same, genetically, as half-siblings, would they not? That could subtract half a generation (or however you want to term it) from how closely related you are to someone with a DNA match, would it not?
I have not done any DNA tests so it is not relevant to me, but it might be to other people.

To K Southall:
If your aunty, the twin of your mother, had children, and they did a DNA test, would they be shown as closer to being your half-siblings or your 1st cousins?




(I probably should have said 'non-identical' twins rather that 'un-identical', but I find the term 'fraternal' confusing as it is used for all 3 types of non-identical twins, but it literally means brothers, though occasionally 'sororal', meaning sisters, can be used, though rarely. Never have I heard anyone call my non-identical sisters 'fraternal twins', but that is just my personal experience.)

A fused placenta would count as one of those weird exceptions I mentioned. There are probably other exceptions.
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Re: Twins' birth records

Postby ksouthall » Mon Aug 12, 2019 4:37 pm

Robbie J N wrote:If you have an ancestor who was an identical twin and you do a DNA test, then if the other identical twin has descendants that are on the DNA database too, then it would show you to be more closely related than you are, if you see what I mean. Cousins who have parents that are identical twins would be the same, genetically, as half-siblings, would they not? That could subtract half a generation (or however you want to term it) from how closely related you are to someone with a DNA match, would it not?
I have not done any DNA tests so it is not relevant to me, but it might be to other people.

To K Southall:
If your aunty, the twin of your mother, had children, and they did a DNA test, would they be shown as closer to being your half-siblings or your 1st cousins?


In answer to your question about whether or not children of identical twins would be like genetic half-siblings, I don't think it's that straightforward.

My cousin has had a DNA test done and comes up as Close Family - 1st Cousin. None of our siblings has done a DNA test so we don't know if they'd come us as more closely related. However, here are the closest matches for me and two of my children, in order.

My DNA matches are as follows:

Aunt (mum's twin) - Shared DNA: 3,463 cM across 60 segments
My Youngest Son - Shared DNA: 3,445 cM across 84 segments
My Middle Son - Shared DNA: 3,445 cM across 70 segments
Aunt (mum's older sister) - Shared DNA: 1,771 cM across 59 segments
Cousin - Shared DNA: 1,764 cM across 60 segments
Son of Cousin - Shared DNA: 768 cM across 31 segments

My Middle Son's DNA matches are as follows:

With Me - Shared DNA: 3,445 cM across 70 segments
With My Youngest Son - Shared DNA: 2,435 cM across 77 segments
With My Aunt (mum's twin) - Shared DNA: 1,676 cM across 58 segments
With My Cousin - Shared DNA: 939 cM across 41 segments
With My Aunt (mum's older sister) - Shared DNA: 838 cM across 43 segments
With His Second Cousin (Son of My Cousin) - Shared DNA: 409 cM across 24 segments

My Youngest Son's DNA matches are as follows:

With Me - Shared DNA: 3,445 cM across 84 segments
With My Middle Son - Shared DNA: 2,435 cM across 77 segments
With My Aunt (mum's twin) - Shared DNA: 1,506 cM across 48 segments
With My Aunt (mum's older sister) - Shared DNA: 766 cM across 37 segments
With My Cousin - Shared DNA: 697 cM across 32 segments
With His Second Cousin (Son of My Cousin) - Shared DNA: 351 cM across 13 segments

cM means centimorgans. I'm not sure what all the numbers mean. However, the differences will be down to which DNA segments have been inherited and from which parent/grandparent/etc. Perhaps someone who has a better understanding of DNA might be able to help with understanding the numbers.
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Re: Twins' birth records

Postby DianaCanada » Mon Sep 02, 2019 8:14 pm

My daughter's paternal grandfather was an identical twin. The twins married first cousins! Both daughter and the other twin's grand daughter have tested on Ancestry and share 510 cM which is much more than regular 2nd cousins would share.

I guess in the case of twins born before and after midnight, they would be registered in order of birth!
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Re: Twins' birth records

Postby ksouthall » Sun Sep 15, 2019 12:27 pm

ksouthall wrote:I'm updating this to incorporate the results from my other son's DNA test.

My DNA matches are as follows:

Aunt (mum's twin) - Shared DNA: 3,463 cM across 60 segments
My Youngest Son - Shared DNA: 3,445 cM across 84 segments
My Middle Son - Shared DNA: 3,445 cM across 70 segments
My Oldest Son - Shared DNA: 3,407 cM across 83 segments
Aunt (mum's older sister) - Shared DNA: 1,771 cM across 59 segments
Cousin - Shared DNA: 1,764 cM across 60 segments
Son of Cousin - Shared DNA: 768 cM across 31 segments

My Middle Son's DNA matches are as follows:

With Me - Shared DNA: 3,445 cM across 70 segments
My Oldest Son - Shared DNA: 2,454 cM across 77
With My Youngest Son - Shared DNA: 2,435 cM across 77 segments
With My Aunt (mum's twin) - Shared DNA: 1,676 cM across 58 segments
With My Cousin - Shared DNA: 939 cM across 41 segments
With My Aunt (mum's older sister) - Shared DNA: 838 cM across 43 segments
With His Second Cousin (Son of My Cousin) - Shared DNA: 409 cM across 24 segments

My Youngest Son's DNA matches are as follows:

With Me - Shared DNA: 3,445 cM across 84 segments
With My Middle Son - Shared DNA: 2,435 cM across 77 segments
My Oldest Son - Shared DNA: 2,366 cM across 70
With My Aunt (mum's twin) - Shared DNA: 1,506 cM across 48 segments
With My Aunt (mum's older sister) - Shared DNA: 766 cM across 37 segments
With My Cousin - Shared DNA: 697 cM across 32 segments
With His Second Cousin (Son of My Cousin) - Shared DNA: 351 cM across 13 segments


My Oldest Son's DNA matches are as follows:

With Me - Shared DNA: 3,407 cM across 83 segments

With My Middle Son - Shared DNA: 2,454 cM across 77 segments
With My Youngest Son - Shared DNA: 2,366 cM across 70 segments
With My Aunt (mum's twin) - Shared DNA: 1,733 cM across 63 segments
With My Aunt (mum's older sister) - Shared DNA: 916 cM across 46 segments
With My Cousin - Shared DNA: 834 cM across 37 segments
With His Second Cousin (Son of My Cousin) - Shared DNA: 377 cM across 20 segments


According to http://www.whoareyoumadeof.com, "two people who are confirmed full second cousins who share both great-grandparents should share between 75-360 centimorgans (cMs)."

My three sons share 409 cMs (middle son), 377 cMs (oldest son) and 351 cMs (youngest son) with their second cousin, towards the top end or above the general shared DNA between second cousins.

I'm not sure what significance the number of shared DNA segments means.
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