Re: genetic testing & CHARGE

[Guest guest]

Barbara,

If your child with CHARGE has an identifiable CHD7 mutation, then

prenatal DNA testing (to look for the same mutation) would be

straightforward. Fetal DNA can be obtained by CVS (at around 10

weeks) or amniocentesis (at around 16 weeks). CHD7 testing of the

first child with CHARGE is expensive (about $2-3,000). Looking for

the same mutation in a fetus is far less (but the CVS or amino can get

pretty expensive). the chance the next baby will have a mutation is

about 1-2%. If a second bay has a mutation, the DNA cannot tell you

what features the child will have. Ultrasound helps some with that.

If no CHD7 mutation is identified, ultrasound (at 20-24 weeks,

ideally) can still give you some information. The Genetics section of

the Manual (available at the CHARGE Syndrome Foundation website

www.chargesyndrome.org) has a list of ultrasound features to look for,

including heart, kidneys, face (clefts), and excess amniotic fluid.

3D ultrasound of the ears can also be really helpful - that's how Tate

was diagnosed.

Normal ultrasound DOES NOT rule out CHARGE. Earlier today I wrote

about a mom in NY who just had her second child with CHARGE. Her

first died, so no DNA testing had been done. She had lots of

ultrasounds and saw nothing wrong. The baby has CHARGE, but doesn't

have features which would have been obvious on ultrasound - except

maybe the ears, but they didnt' look.

So generally, that is where things stand. If you have more specific

questions, ask away and I'll do my best to answer.

Meg

Meg Hefner MS

Genetic Counselor, St. Louis MO

>

> I am writing specifically to Meg but any input would be appreciated.

> Last year I began questioning what testing was available to parents

> thinking about trying to get pregnant who have a child with CHARGE.

> Also, WHat is available to testing the fetus? Last year it didn't

> seem conclusive, what if anything has changed? WHat is available and

> how can someone get tested?

> Barbara (mom to , 6)

>

[Guest guest]

Meg

My daughter Amélie hasthe mutation CHD7, if my other daughters wanted to be

tested if they were pregnant,

would amniocentesis or chorionic villus sampling work for them, seen as they

are siblings?

I ask this although my daugters are teenagers, however it is always nagging

me, in the UK these tests are free,

so financial consideration would not be a worry.

Thanks Lesley

>

> Barbara,

> If your child with CHARGE has an identifiable CHD7 mutation, then

> prenatal DNA testing (to look for the same mutation) would be

> straightforward. Fetal DNA can be obtained by CVS (at around 10

> weeks) or amniocentesis (at around 16 weeks). CHD7 testing of the

> first child with CHARGE is expensive (about $2-3,000). Looking for

> the same mutation in a fetus is far less (but the CVS or amino can get

> pretty expensive). the chance the next baby will have a mutation is

> about 1-2%. If a second bay has a mutation, the DNA cannot tell you

> what features the child will have. Ultrasound helps some with that.

>

> If no CHD7 mutation is identified, ultrasound (at 20-24 weeks,

> ideally) can still give you some information. The Genetics section of

> the Manual (available at the CHARGE Syndrome Foundation website

> www.chargesyndrome.org) has a list of ultrasound features to look for,

> including heart, kidneys, face (clefts), and excess amniotic fluid.

> 3D ultrasound of the ears can also be really helpful - that's how Tate

> was diagnosed.

>

> Normal ultrasound DOES NOT rule out CHARGE. Earlier today I wrote

> about a mom in NY who just had her second child with CHARGE. Her

> first died, so no DNA testing had been done. She had lots of

> ultrasounds and saw nothing wrong. The baby has CHARGE, but doesn't

> have features which would have been obvious on ultrasound - except

> maybe the ears, but they didnt' look.

>

> So generally, that is where things stand. If you have more specific

> questions, ask away and I'll do my best to answer.

> Meg

> Meg Hefner MS

> Genetic Counselor, St. Louis MO

>

>

> >

> > I am writing specifically to Meg but any input would be appreciated.

> > Last year I began questioning what testing was available to parents

> > thinking about trying to get pregnant who have a child with CHARGE.

> > Also, WHat is available to testing the fetus? Last year it didn't

> > seem conclusive, what if anything has changed? WHat is available and

> > how can someone get tested?

> > Barbara (mom to , 6)

>

> >

>

>

>

[Guest guest]

Lesley,

Yes, if your other daughters wanted to rule out CHARGE in their

pregnancies, that would be pretty easy. Statistically, they are not

at any increased risk, but we do prenatal diagnosis for people in

situations like that all the time [sisters of someone with Down

syndrome do not have an increased risk, but they often want testing

anyway]

To do it, the sample (from CVS or amino) would need to be sent to a

lab that does CHD7 testing (the best would be the same one that tested

Amelie) and they must know which mutation Amelie carries. Checking

with the lab to be sure they can test for that particular mutation is

important. Be sure you have really good documentation of Amelie's

CHD7 mutation and check (ahead of time)to be sure samples will be sent

to a lab that can test for it.

Those of you who had CHD7 testing through Baylor or any other research

study - you got a recommendation to have the mutation confirmed by a

commercial lab (like GeneDx or PreventionGenetics in the US). The

reason is to have official confirmation of the specific mutation -

which is what is needed to test other family members. The

confirmation testing does not have to be sequencing again (the

expensive test), it should be targeted mutation analysis (the far

cheaper test)- the lab needs to know which mutation Baylor found -

then they repeat the test just for that mutation. The commercial lab

is simply confirming the typo found in the document which is CHD7.

Meg

Meg Hefner MS

Genetic Counselor St Louis MO

> >

> > Barbara,

> > If your child with CHARGE has an identifiable CHD7 mutation, then

> > prenatal DNA testing (to look for the same mutation) would be

> > straightforward. Fetal DNA can be obtained by CVS (at around 10

> > weeks) or amniocentesis (at around 16 weeks). CHD7 testing of the

> > first child with CHARGE is expensive (about $2-3,000). Looking for

> > the same mutation in a fetus is far less (but the CVS or amino can get

> > pretty expensive). the chance the next baby will have a mutation is

> > about 1-2%. If a second bay has a mutation, the DNA cannot tell you

> > what features the child will have. Ultrasound helps some with that.

> >

> > If no CHD7 mutation is identified, ultrasound (at 20-24 weeks,

> > ideally) can still give you some information. The Genetics section of

> > the Manual (available at the CHARGE Syndrome Foundation website

> > www.chargesyndrome.org) has a list of ultrasound features to look for,

> > including heart, kidneys, face (clefts), and excess amniotic fluid.

> > 3D ultrasound of the ears can also be really helpful - that's how Tate

> > was diagnosed.

> >

> > Normal ultrasound DOES NOT rule out CHARGE. Earlier today I wrote

> > about a mom in NY who just had her second child with CHARGE. Her

> > first died, so no DNA testing had been done. She had lots of

> > ultrasounds and saw nothing wrong. The baby has CHARGE, but doesn't

> > have features which would have been obvious on ultrasound - except

> > maybe the ears, but they didnt' look.

> >

> > So generally, that is where things stand. If you have more specific

> > questions, ask away and I'll do my best to answer.

> > Meg

> > Meg Hefner MS

> > Genetic Counselor, St. Louis MO

>

[Guest guest]

Meg

Thanks for Clarifying this. Amélie was tested in Holland and I have a letter

with

her mutation on it. I am a student midwife at present, and so prenatal

screening

is a huge issue for many families, I always think of how my girls will feel

when the time comes,

regarding their sisters disability and the worry this may cause all of us.

many thanks Lesley

>

> Lesley,

> Yes, if your other daughters wanted to rule out CHARGE in their

> pregnancies, that would be pretty easy. Statistically, they are not

> at any increased risk, but we do prenatal diagnosis for people in

> situations like that all the time [sisters of someone with Down

> syndrome do not have an increased risk, but they often want testing

> anyway]

>

> To do it, the sample (from CVS or amino) would need to be sent to a

> lab that does CHD7 testing (the best would be the same one that tested

> Amelie) and they must know which mutation Amelie carries. Checking

> with the lab to be sure they can test for that particular mutation is

> important. Be sure you have really good documentation of Amelie's

> CHD7 mutation and check (ahead of time)to be sure samples will be sent

> to a lab that can test for it.

>

> Those of you who had CHD7 testing through Baylor or any other research

> study - you got a recommendation to have the mutation confirmed by a

> commercial lab (like GeneDx or PreventionGenetics in the US). The

> reason is to have official confirmation of the specific mutation -

> which is what is needed to test other family members. The

> confirmation testing does not have to be sequencing again (the

> expensive test), it should be targeted mutation analysis (the far

> cheaper test)- the lab needs to know which mutation Baylor found -

> then they repeat the test just for that mutation. The commercial lab

> is simply confirming the typo found in the document which is CHD7.

> Meg

>

> Meg Hefner MS

> Genetic Counselor St Louis MO

>

>

> > >

> > > Barbara,

> > > If your child with CHARGE has an identifiable CHD7 mutation, then

> > > prenatal DNA testing (to look for the same mutation) would be

> > > straightforward. Fetal DNA can be obtained by CVS (at around 10

> > > weeks) or amniocentesis (at around 16 weeks). CHD7 testing of the

> > > first child with CHARGE is expensive (about $2-3,000). Looking for

> > > the same mutation in a fetus is far less (but the CVS or amino can get

> > > pretty expensive). the chance the next baby will have a mutation is

> > > about 1-2%. If a second bay has a mutation, the DNA cannot tell you

> > > what features the child will have. Ultrasound helps some with that.

> > >

> > > If no CHD7 mutation is identified, ultrasound (at 20-24 weeks,

> > > ideally) can still give you some information. The Genetics section of

> > > the Manual (available at the CHARGE Syndrome Foundation website

> > > www.chargesyndrome.org) has a list of ultrasound features to look for,

> > > including heart, kidneys, face (clefts), and excess amniotic fluid.

> > > 3D ultrasound of the ears can also be really helpful - that's how Tate

> > > was diagnosed.

> > >

> > > Normal ultrasound DOES NOT rule out CHARGE. Earlier today I wrote

> > > about a mom in NY who just had her second child with CHARGE. Her

> > > first died, so no DNA testing had been done. She had lots of

> > > ultrasounds and saw nothing wrong. The baby has CHARGE, but doesn't

> > > have features which would have been obvious on ultrasound - except

> > > maybe the ears, but they didnt' look.

> > >

> > > So generally, that is where things stand. If you have more specific

> > > questions, ask away and I'll do my best to answer.

> > > Meg

> > > Meg Hefner MS

> > > Genetic Counselor, St. Louis MO

> >

>

>

>