mitochondrial dna mutation

[Guest guest]

Hi all,

Maybe someone can answer my dumb question: Are mitochondrial DNA mutations a

kind of gene variant?

Anyway, I hope that as studies like the one below are published, more and

more people will begin to wonder if gene variants are also important in

hard-to-diagnose diseases. 100% of the kids with the mutation (below) who

receive aminoglycoside antibiotics have permanent, profound hearing loss!

Sue B.

New England Journal of Medicine

Volume 360:640-642 February 5, 2009 Number 6

Prevalence of Mitochondrial 1555AG Mutation in European Children

To the Editor:

Aminoglycoside antibiotics are used worldwide to treat gram-negative sepsis.

Since these drugs are ototoxic and nephrotoxic, drug levels are closely

monitored. However, their effect on patients with the mitochondrial DNA

mutation m.1555AG is dramatic. rs of this mutation have permanent,

profound hearing loss after receiving aminoglycosides, even when drug levels

are within the therapeutic range.1,2 A review of previous studies indicates

that after aminoglycoside exposure, penetrance of deafness in this

population is close to 100%.3

Estimates of the prevalence of the m.1555AG mutation have been hampered

because of the small numbers of patients in such . . . [Full Text of this

Article]

http://content.nejm.org/cgi/content/short/360/6/640

[Guest guest]

This is from a layman, so bear with me. From what I have read our cells are made up of nuclear DNA and mitochondrial DNA. The Mitochondrial DNA is from bacteria that started living in our cells before there was plants and animals. This bacteria has 27 genes and still has wild cousins closely related out in the world. This Mito DNA is considered the power house of the cell, and is what helps account for a lot of the workings of the cell. After over 1 billion years we could not survive without them. Jimd

From: <rhbailey@...>Subject: [infections] mitochondrial dna mutation"infections " <infections >Date: Wednesday, February 4, 2009, 6:33 PM

Hi all,Maybe someone can answer my dumb question: Are mitochondrial DNA mutations akind of gene variant?Anyway, I hope that as studies like the one below are published, more andmore people will begin to wonder if gene variants are also important inhard-to-diagnose diseases. 100% of the kids with the mutation (below) whoreceive aminoglycoside antibiotics have permanent, profound hearing loss!Sue B.New England Journal of MedicineVolume 360:640-642 February 5, 2009 Number 6Prevalence of Mitochondrial 1555AG Mutation in European ChildrenTo the Editor: Aminoglycoside antibiotics are used worldwide to treat gram-negative sepsis.Since these drugs are ototoxic and nephrotoxic, drug levels are closelymonitored. However, their effect on patients with the mitochondrial DNAmutation m.1555AG is dramatic. rs of this mutation have permanent,profound hearing loss after

receiving aminoglycosides, even when drug levelsare within the therapeutic range.1,2 A review of previous studies indicatesthat after aminoglycoside exposure, penetrance of deafness in thispopulation is close to 100%.3Estimates of the prevalence of the m.1555AG mutation have been hamperedbecause of the small numbers of patients in such . . . [Full Text of thisArticle]http://content. nejm.org/ cgi/content/ short/360/ 6/640

[Guest guest]

Hi, Sue.

Both mutations and polymorphisms or SNPs are gene variants. Generally

speaking, mutations are gene variants that occur in less than about 1%

of the population, and their consequences are more serious.

Polymorphisms are much more common, and their consequences are either

unobservable or less serious than those of mutations. There may be

some fuzzy middle ground between these two, but that's the essence of it.

Rich

>

> Hi all,

>

> Maybe someone can answer my dumb question: Are mitochondrial DNA

mutations a

> kind of gene variant?

>

> Anyway, I hope that as studies like the one below are published,

more and

> more people will begin to wonder if gene variants are also important in

> hard-to-diagnose diseases. 100% of the kids with the mutation

(below) who

> receive aminoglycoside antibiotics have permanent, profound hearing

loss!

>

> Sue B.

>

> New England Journal of Medicine

> Volume 360:640-642 February 5, 2009 Number 6

>

> Prevalence of Mitochondrial 1555AG Mutation in European Children

>

> To the Editor:

>

> Aminoglycoside antibiotics are used worldwide to treat gram-negative

sepsis.

> Since these drugs are ototoxic and nephrotoxic, drug levels are closely

> monitored. However, their effect on patients with the mitochondrial DNA

> mutation m.1555AG is dramatic. rs of this mutation have permanent,

> profound hearing loss after receiving aminoglycosides, even when

drug levels

> are within the therapeutic range.1,2 A review of previous studies

indicates

> that after aminoglycoside exposure, penetrance of deafness in this

> population is close to 100%.3

>

> Estimates of the prevalence of the m.1555AG mutation have been hampered

> because of the small numbers of patients in such . . . [Full Text of

this

> Article]

>

> http://content.nejm.org/cgi/content/short/360/6/640

>

[Guest guest]

Hi Rich,

Thanks, Rich. Am I correct in assuming that both types of gene variants occur in

both nuclear DNA and mtDNA?

Sue

>

> Hi, Sue.

>

> Both mutations and polymorphisms or SNPs are gene variants...

>

> Rich

[Guest guest]

Hi, Sue.

I believe that's correct. I haven't heard much about mild polymorphisms in

mtDNA, but they must occur there, too. I think the more serious mutations in

mtDNA have gotten more attention.

Rich

--- In infections , " sue_upstate " <rhbailey@...>

wrote:

>

> Hi Rich,

>

> Thanks, Rich. Am I correct in assuming that both types of gene variants occur

in both nuclear DNA and mtDNA?

>

> Sue

>

> >

> > Hi, Sue.

> >

> > Both mutations and polymorphisms or SNPs are gene variants...

> >

> > Rich

>