a rather late reply to Nicol's post

[Guest guest]

Hi

Ok, a

little in replying to you on the board…sorry about that … I wanted

to be sure of what I have written. Things that are facts are in red. Things

that I have personally estimated/discovered, by talking to geneticists, are in

blue. Please remember that I am not in the medical profession, so

consider this information as the best efforts of an informed friend.

It is

quite hard writing all this down. I am not a medic, and I wanted to be

absolutely certain that I don’t mislead anyone. But at the same time I

wanted it to be easy to read. So I have simplified things. So if you reading

this, and have met a geneticist and they have told you something that is a

slightly variation – then you should understand that they gave perhaps a

more complete or detailed answer.

However,

if they have said something that is very different – then please ask them

to look at more recent research. If they are looking at information from more

than about 6 years ago – then it will, most likely, be out of date.

I am very grateful to 2 medics who are members of this group, who have

checked the text of this email before I posted it.

A few basics before

I try to explain.

· The infertility issue only affects women.

Specifically – the infertility is because of P.O.F (which stands for

“Premature Ovarian Failure” – there is heaps of info on the

internet about this) and early menopause. Some women with Type 1 BPES may

become pregnant. But I don’t want to elaborate more at this

point, because this is very detailed, complicated, and I am not qualified to

advise.

· If men with BPES are infertile, it is entirely

unrelated to BPES.

· When people say that there is a 50% chance of the child

having BPES, that means each child has a 50% chance.

It doesn’t mean that if you have 2 children, and they both have BPES, and

you are planning on having a third child, that child is less likely to have

BPES. We all know that if you have 2 boys, and are expecting a third

child, there is a 50% chance that your baby will be a boy, and 50% chance that

it will be a girl.

· When a child inherits BPES from a parent (the parent

having typical BPES, ie BPES alone, with no other issues) then they may have an

appearance that is more severe, or less severe, than their parent.

Is there

any truth in Type 1 coming from mom, and Type 2 from dad?

No. This

is not the case. But you need to read the text below to understand a bit more.

This sort of sentence is a bit misleading. It is not clear if the person

who said it was referring to inherited BPES (where one parent has BPES) or

simply any person with BPES.

This section

is about inherited BPES, type 1 and type 2

Parents

who have BPES – and this is confirmed

· If you are a parent with BPES (confirmed by a physician) then each

child you have has a 50% chance of having BPES. BPES is “autosomal

dominant” and so in each pregnancy there is a 50% chance of a child

getting BPES. A parent can only pass on the same type as the one they

have.

To make it easier to understand, please look below, but if you want – you

can skip reading the detail.

O If a Mother has Type 1, and falls pregnant, it is

because she doesn't have ovarian failure at the time of falling pregnant, or

ovulated the month in which she fell pregnant., then each child has a 50%

chance of having BPES.

If the child is a girl, she is going to have Type 1 … but she’ll be

similar to her mother, but may not be exactly the same. She will have

a higher chance of falling pregnant the younger she is, ie late teens and

possibly early 20's.

O If a Mother has Type 2, and

then each child has a 50% chance of having BPES. If the child is a girl, she is

going to have Type 2, just like her mother.

O If a father has BPES: if he is has the type 1 gene, each

child of his has a 50% chance of having BPES. If he has a daughter who has

BPES, she will be Type 1. She will get POF and early menopause. She will have

a higher chance of falling pregnant the younger she is, ie late teens and

possibly early 20's.

O If a father has BPES: if he is has the

type 2 gene, each child of his has a 50% chance of having BPES. If he has a

daughter who has BPES, she’ll have type 2 as well.

What if

neither parent has BPES? Then read below.

This

section is about children where there is no confirmed BPES in either parent

It is possible for a person to be born with BPES, and neither parent

look like they have BPES – YES – this

happens to lots and lots of people

Let’s look at this more closely

Possibility (a) New Mutation (by far the most

common possibility)

There is absolutely no trace of BPES in either parent.

In which case … this is called a “de novo

mutation” or “new mutation”. It means that the mutation

started here, with this child, before it was born.

De novo mutations, in themselves, are not rare. Here is an

example …you probably have heard of people with 2 webbed toes? Dan

Aykroyd, Charlotte Church, Stalin. Not rare, about 1 in 2,000 people have this.

Possibility ( Germline Mosaicism (not

nearly as common as possibility 1) This is all very very rare,

and it should not be something to worry about.

Whilst it looks like neither parent has BPES, it turns out

that one parent has what is called “germline mosaicism”.

This means that a very small portion of their eggs/semen are

affected. Neither parent may have anything at all in their appearance to

suggest this …. Or … there could be a tiny tiny hint in the parent.

They may look just as any other person, but a medic with plenty of experience

in this field would be able to detect a tiny hint.

This is pretty rare. I think that in our group of

800 people/families – I know of about 4 or 5 cases like this.

What I do know is that it is very hard to detect germline

mosaicism.

If you suspect you are in this category, the chance of having

another child with BPES is less than 10%.

Please please don’t worry about this.

Stats

I

think that about 6 to 8 people per million have BPES. But I estimated

this about 5 years ago, and I discussed it with 2 geneticists. They told

me that they did not have estimates, but my research seemed to be

reasonable.

Shireen

Mohandes

London,

England