Mitochondrial DNA diseases

Question 1

name the disease that is the most common mitochondrial DNA (mtDNA)-related disorder, causing subacute loss of central vision in young adults, predominantly men. is usually due to homoplasmic mutations in one of three genes encoding complex I subunits

Answer 1

LHON

Leber’s Hereditary Optic Neuropathy

Question 2

name the mitochondrial disease that is commonly due to nuclear DNA (nDNA) mutations rather than to mtDNA mutations. The mutations are most frequently in subunits of complex I or in assembly factors of complex IV. The effects are mostly seen in the developing nervous system and are very serious.

Answer 2

Leigh’s Syndrome

Question 3

name the disease that is a multisystem disorder in which brain, muscle and the endocrine system are predominantly involved and is often fatal in childhood or in young adulthood. Unique to this disease are the transient eponymous stroke-like episodes, which are most often due to infarcts in the temporal and occipital lobes and are associated with hemiplegia and cortical blindness. Although we still do not understand the cause, their occurrence highlights the fact that this disease is also an angiopathy, making it almost unique among the mitochondrial diseases. Mutations in this disease have been associated with affecting both tRNA and protein-coding genes.

Answer 3

MELAS

Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes

Question 4

name the disease that for unknown reasons, is due almost exclusively to mutations in tRNALys. It is associated with a rather different set of signs and symptoms from the other diseases, often including cervical lipomas as well as myoclonus and epilepsy

Answer 4

MERRF

Myoclonus epilepsy and ragged red fibres

Question 5

Name the mitochondrial disease that is caused by a 70% mutant mtDNA that is caused by a mutation to a nucleotide that also causes a different mitochondrial disease

Answer 5

NARP

Neuropathy, ataxia and retinitis pigmentosa

Question 6

Name the mitochondrial disease that is caused by a 90% mutant mtDNA that is caused by a mutation to a nucleotide that also causes a different mitochondrial disease

Answer 6

MILS

Maternally inherited Leighs Syndrome

Question 7

name the mitochondrial disease that causes infants to be very ill but if sustained, around the age of two dysfunction is spontaneously reversed and full mitochondrial function is gained

Answer 7

Reversible Respiratory Chain Deficiency

Question 8

Name the mitochondrial disease that is marked by opthalmoplegia and ptosis before age twenty, also accompanied by another serious problem. These are caused by sporadic deletions in the mtDNA in all tissues

Answer 8

Kearns - Sayre Syndrome