Phenotype in Mitochondrial Disease

[Guest guest]

Thought you might be interested in this as it discusses some new findings.

Curr Opin Neurol. 2005 Oct;18(5):538-42.

The expanding phenotype of mitochondrial myopathy.

Dimauro S, Gurgel-Giannetti J.

aDepartment of Neurology, Columbia University Medical Center, New York, New

York, USA bDepartment of Pediatrics, Federal University of Minas Gerais, Belo

Horizonte, Brazil.

PURPOSE OF REVIEW: Our understanding of mitochondrial diseases (defined

restrictively as defects in the mitochondrial respiratory chain) continues to

progress apace. In this review we provide an update of information regarding

disorders that predominantly or exclusively affect skeletal muscle. RECENT

FINDINGS: Most recently described mitochondrial myopathies are due to defects in

nuclear DNA, including coenzyme Q10 deficiency, and mutations in genes that

control mitochondrial DNA (mtDNA) abundance and structure such as POLG and TK2.

Barth syndrome, an X-linked recessive mitochondrial myopathy/cardiopathy, is

associated with altered lipid composition of the inner mitochondrial membrane,

but a putative secondary impairment of the respiratory chain remains to be

documented. Concerning the 'other genome', the role played by mutations in

protein encoding genes of mtDNA in causing isolated myopathies has been

confirmed. It has also been confirmed that mutations in tRNA genes of mtDNA can

cause predominantly myopathic syndromes and - contrary to conventional wisdom -

these mutations can be homoplasmic. SUMMARY: Defects in the mitochondrial

respiratory chain impair energy production and almost invariably involve

skeletal muscle, causing exercise intolerance, myalgia, cramps, or fixed

weakness, which often affects extraocular muscles and results in droopy eyelids

(ptosis) and progressive external ophthalmoplegia.

PMID: 16155436 [PubMed - in process]

Joanne Kocourek (mom to , lies, and )

visit us at: http://www.caringbridge.org/il/annakris

[Guest guest]

Thank you, Joanne. Very interesting.

Barbara

> Phenotype in Mitochondrial Disease

>

> Thought you might be interested in this as it discusses some new findings.

>

> Curr Opin Neurol. 2005 Oct;18(5):538-42.

>

> The expanding phenotype of mitochondrial myopathy.

>

> Dimauro S, Gurgel-Giannetti J.

>

> aDepartment of Neurology, Columbia University Medical Center, New York,

New

> York, USA bDepartment of Pediatrics, Federal University of Minas Gerais,

Belo

> Horizonte, Brazil.

>

> PURPOSE OF REVIEW: Our understanding of mitochondrial diseases (defined

> restrictively as defects in the mitochondrial respiratory chain) continues

to progress

> apace. In this review we provide an update of information regarding

disorders that

> predominantly or exclusively affect skeletal muscle. RECENT FINDINGS: Most

> recently described mitochondrial myopathies are due to defects in nuclear

DNA,

> including coenzyme Q10 deficiency, and mutations in genes that control

> mitochondrial DNA (mtDNA) abundance and structure such as POLG and TK2.

> Barth syndrome, an X-linked recessive mitochondrial myopathy/cardiopathy,

is

> associated with altered lipid composition of the inner mitochondrial

membrane, but

> a putative secondary impairment of the respiratory chain remains to be

> documented. Concerning the 'other genome', the role played by mutations in

> protein encoding genes of mtDNA in causing isolated myopathies has been

> confirmed. It has also been confirmed that mutations in tRNA genes of mtD

> NA can

> cause predominantly myopathic syndromes and - contrary to conventional

wisdom

> - these mutations can be homoplasmic. SUMMARY: Defects in the

mitochondrial

> respiratory chain impair energy production and almost invariably involve

skeletal

> muscle, causing exercise intolerance, myalgia, cramps, or fixed weakness,

which

> often affects extraocular muscles and results in droopy eyelids (ptosis)

and

> progressive external ophthalmoplegia.

>

> PMID: 16155436 [PubMed - in process]

>

>

> Joanne Kocourek (mom to , lies, and )

> visit us at: http://www.caringbridge.org/il/annakris

>

>