Genealogy Chat

Only certain types of Downs Syndrome are hereditary. Most are spontaneous and occur at conception - a blip in reading the DNA, not a fault in the DNA itself. The ones which are hereditary, can more properly be said to 'run in families', as it would seem that it is an inherited fault which makes the genes wrongly read the information at the time of conception, rather than just a random misreading. I wonder if that Vicar ever DID anything with his findings, though? How interesting. All cases of Huntington's, a terrible inherited diease, can be traced back to one woman who lived in Sussex (from memory) in the early 1600s, and emigrated to USA. Every case documented so far by medical genealogists is traced back to her and her sister - the sister was hung as a witch, due no doubt to the terrible grimacing and dancing around, poor soul. Huntington's appears to be a random repeating of part of a gene which has no known purpose. If the random repeats are less than, I think, 45, then the person is a carrier and not a sufferer. But where close kin marry, who both have this gene, then the repeats escalate and the child is a sufferer, rather than just a carrier. Sorry! I get carried away with this! OC

The following is from ASK: Inbreeeding is a problem especially if you are to have children with a very close relative. The closer you are to a particular relative, the worst your chances are of having a very defective child. The reason being is that every human being usually has a unique set of genes and out of all of these genes, many may be defective. But, as human genetics permits such defects since we usually carry each gene in pairs, even if we have a defective gene (say from our dad) we may still be well off because we have a perfect gene from the mother. (I used to live in a highly ethnic area, where 1st cousins were marrying on a regular basis, as had their parents AND grandparents. Health visitors were trying to warn about the dangers, and there were some children from the more orthodox families who had disabilities.)

In the next door village (3 miles away) to where I grew up the vicar kept a register up to the 1960s of who had married whom in the village as there was so much in-breeding and a high % of people were affected with Downs syndrome - which goes back to masking the defective gene as previous threads have alluded to. There was a lot of 'in fighting' as well but wobetide any outsider who spoke ill of somebody from the village as you were bound to be talking to a relative and then the ranks were closed! Bo

Clive Yes, I am sure lead water pipes did their bit! Another possible reason which occurs to me - my rural ancestors, all farmers, would have had an unlimited supply of fresh, healthy food, with a varied diet including meat and fresh vegetables. Once in the Cities, many poor people adopted a diet of unrelieved stodge such as bread and potatoes, with little meat and or veg, and not fresh when they could get it. Most cheap foods were highly adulterated anyway. A diet high in carbohydrate does have a negative effect on fertility (and it also turns you into a dumbed down, obedient sheep!) OC

Getting away from cousins marrying, I think the funniest thing I have is where my 2 x great grandfather married for the second time. They had a grandchild living with them(from first wife) and she married, and after grandad died, his second wife, married the father of the granddaughter's husband. He was a lot younger than her. Talk about keep it in the family.

As I understand it before most of us can remember the Romans had fertility problems which moder boffins (some) put down to the use of lead in drinking and eating utensils. If my memory serves me right moves into towns in the 1880s coincided with the use of lead pipes for water supply. Is there a connection? As a kid once we were on piped water we were always told to drink only from the kitchen sink tap (OK, we could use cups but the water had to to come from that tap) because it was the only one in the house not supplied by a lead pipe. C

Thanks for that OC. I hadn't thought that an urban/slum environment could have been responsible for the fertility drop. But you could be right - it was certainly when my maternal grandparents went to London from Wiltshire. Mind you, they had ten children and it was those children that seemed to suffer with the fertility problems despite marrying 'outsiders' as it were. Yes, I certainly wouldn't believe the contraception theory either. Given that sheeps intestines 'did the job' in those days it would have been far more likely that country-dwelling people would use them! They were very costly to buy once you got to the city - and very few would have been able to afford them, even had they been aware of them. Now if there had been a World War....... As for genetic problems, I am given to believe that one of the major causes of genetic glitches is old eggs and/or old sperm - and Queen Victoria's elderly father was the cause of the haemophilia that afflicted some of her male descendants. Victoria

Pat That has happened throughout history - second, third and fourth marriages are nothing new, and neither are 'unknown' fathers, multiple relationships etc. Nothing to worry about - the human race manages to go on! OC

Hi Peter, I was interested in your question and the replies you've received but it made me wonder what will happen with our generation of 2nd/3rd marriages, partnerships, half brothers/half sisters. What if sometime in the future they get together and marry without knowing their true family history. Scary or what! Pat

OC Totally agree fascinating subject, we could mull this one over all week and still not have any answers, but a great thread still. Nicky

Nicky You can inherit a faulty gene (obviously!) but the question of why that gene went faulty originally, is a complicated one, and there are many reasons why it did, not many of them to do with inbreeding. Genes which are dangerously faulty, occur in any generation, randomly, for unknown reasons. The sufferer usually dies before they have a chance to pass on the gene and that fault dies out. Other genes with less serious consequences (to survival, that is) are usually masked by a healthy gene, and there can be many generations of healthy individuals carrying that gene, only for it to pop up three hundred years later and cause havoc. Inbreeding will only enforce a fault which previously existed, and the lack of input form a 'healthy' gene pool, allows the fault to surface. Animal breeders have known for many centuries that you can successfully breed better and better specimens by selecting for certain characteristics, but that every so often, an animal will appear with 'faults'. The science of genetics is now providing the answer to the question 'why?' Fascinating subject! OC

Gerri, talking about the 'faulty gene' theory, one of my children has severe eye problems and is also under Moorfields Hospital, this is because unbeknown to my partner and I we both are carriers of the same' faulty gene'. To have this gene we both had to inherit it from one of our parents, and them from one of theirs and so on, its a million to one shot ,if we hadnt met and had a child together neither of us would have been any the wiser, my two other children from a previous marriage are fine, because obviously my ex didnt carry that gene . Nature can be very cruel, but I belive there are a lot of people out there who are carriers of various illnesss and diseases that dont rear their ugly heads unless they meet someone with the same problem. There is currently no test to decipher which parent my partner and I got this from, and quite honestly I dont really want to know anyway, it wouldnt help my daughter. Is this a result form wayback of interbreeding? who knows? we will probably never know. Nicky

Victoria Regarding the drop in fertility in the 1880s - I have read that it was because people started using contraception. I do not believe this for one minute! There was no reliable method of contraception for women and nowhere to get it if there was.Information about contraception was a closely guarded medical secret, frowned on by the Church and extablishment alike. And as we all know, men are rather inefficient at using contraception, lol. The only reliable method was abstinence, and this again seems unlikely in the extreme. The only difference I can see in MY family, is that they moved from a very rural setting, into the slums of Manchester and I have wondered if industrial pollution affected their fertility. And another thing - it is only when they start mixing with the 'outside world' in terms of marriage and beeding, that they started to die out! OC

I can say the same for the small 3000 inhabitants of Bures St mary Suffolk. I have Willinghams, Sealeys and Cardy's intermarrying regularly!!

Hi You should see the Worners in Martock Somerset !! My ggg grandparents were second cousins once removed - her grandmother, and his great-grandmother were the youngest and oldest of the family, separated by 23 years. By the time they married, all the older people who knew were dead. Two of her first cousins married each other, as did one pair of their aunts and uncles. I don't know if the Somerset genes are stronger in our family because of doubling up !! Diane

Absolutely!! Some of my grandmother's siblings seemed challenged in terms of reproduction and I often wondered whether the genes had finally decided that enough was enough and called it quits. From families with ten or more children some weren't able to have any. Incidentally, when I used to use the microfische for research I noticed that somewhere around the 1880s the whole year's births only took as many microfische as some years needed for a month or two. I often wondered about THAT. Any theories? Victoria

Ummm! OC yes it definately could have been a factor as fertility can definately suffer with the close inbreeding of some animals species...until those affected specimen have been removed from the gene pool.

Kerry Interesting though, that that side of the family suddenly started dying out for various reasons in the late 1800s - never married, or did marry but only had one, or no, children...I have often wondered if the gene pool finally reached its limits of survival! OC

Every animal including the human animal carries a genetic load of defects. When you concentrate the the number of genes by marrying within the same family your chances of the bad ones surfacing increase. But as was said previously the defective genes were already there. In OC's case perhaps with prolonged inbreeding the survival of the fittest had kicked in and many of the defective genes had already been eliminated.

A good eye opener there OC and Summer....Many thanks. (sorry about the punn/pun lol) Gerri x