Table 1 Clinical, biochemical and molecular features of m.14459G > A mutated patients:

Current Study

A

F

Caucasian Haplogroup H2a2

18 m

2 m

LS+Dystonia

Psycomotor delay, hypotonia, dystonia.

MRI: lesions in the basal ganglia and mesencephalum.

36% (muscle)

> 99 (muscle) >99 (blood)

Shoffner et al. [5]

B1-1 (proband)

F

African-American

19y

3 m

LHON

Loss of bilateral vision, optic atrophy

MRI: lesions in caudate nucleus and right putamen

3% (muscle)

>99

Shoffner et al. [5]

B1-2 (proband's mother)

F

African-American

42y

42y

LHON

Loss of bilateral vision, optic atrophy

NP

NP

50

Shoffner et al. [5]

B2

F

Caucasian

13y

3y

Dystonia

Dysarthria, dystonia, quadriparesis

CT: bilateral hipodensity in the putamina. MRI: bilateral lesions in putamen and caudate.

NP

50

Funalot et al. [7]

C2

M

Caucasian Haplogroup T

†32y suicide

18y

LLS+LHON

Bilateral visual failure, hearing loss, ataxia, extrapiramidal signs

MRI: hyperintensity in dorsal midbrain; bilateral lesions in the third ventricle walls.

NP

40

Gropman et al. [9]

D1 (proband)

F

Hispanic

4y

3y

Dystonia

Anarthria, dystonia, spasticity, encefalopathy, neurofibromatosis

MRI: bilateral hyperintensities of the putamen. MRS: elevated lactate.

76% (muscle)

>99

Gropman et al. [9]

D1-2 (proband's mother)

F

Hispanic

35y

34y

neurofibromatosis, muscle weakness

MRI: bitemporal signal abnormalities

NP

>99

Gropman et al. [9]

D1-3 (proband's brother)

M

Hispanic

7y

2y

Dystonia

neurofibromatosis, hemiparesis, cognitive delay

MRI: right sided putaminal infarcts, thickened corpus callosum

NP

>99

Gropman et al. [9]

D1-3 (maternal cousin)

F

Hispanic

5y

5y

-

Hemiparesis

MRI: bilateral putaminal infarcts MRS: elevated lactate

NP

>99

Kirby et al. [6]

E1-1

F

?

†7y

9 m

LS

Motor delay, hypotonia, seizure, dystonia.

CT: bilateral low density lesions of the basal ganglia

25% (fibroblasts)

97 (fibroblasts)

Kirby et al. [6]

E1-2 (proband's brother)

M

?

†10 m

3 m

LS

Hypotonia, neurological and developmental regression, seizure. Metabolic acidosis.

-

6% (muscle) 46% (liver)

97 (muscle, liver)

Kirby et al. [6]

E2

F

?

†8 m

6 m

LS

Developmental delay, athetosis, hypotonia.

MRI: cerebral atrophy, involvement of basal ganglia and medial thalamic nuclei.

15% (fibroblasts) 16% (muscle) 37% (liver)

97 (muscle, liver)

Jun et al. [4]

G1-1 (proband)

F

Hispanic (Native American). Haplogroup D

10y

2y

Dystonia

Dystonia, corticospinal tract dysfunction, dysarthria.

CT: bilateral low density lesions in putamen progressing to the caudate

-

99 (blood)

Jun et al. [4]

G1-2 (proband's brother)

M

Hispanic (Native American). Haplogroup D

13y

13y

Dystonia

Dystonia, intellectual impairmeint.

NP

NP

99 (blood)

Jun et al. [4]

G1-3 (proband's mother)

F

Hispanic (Native American). Haplogroup D

32y

32y

LHON

Bilateral optic atrophy.

NP

NP

73 (blood)

Jun et al. [4]

G1-4 (maternal cousin)

M

Hispanic (Native American). Haplogroup D

?

?

LHON

-

NP

NP

99 (blood)

Jun et al. [4]

G1-5 (maternal relative)

M

Hispanic (Native American). Haplogroup D

?

5y

Dystonia

Dystonia

CT: abnormal basal ganglial lucencies

NP

99 (blood)

Tarnopolsky et al. [8]

E1-1 (proband)

F

Caucasian

45y

8y

Dystonia

Dystonia

MRI: hiperintensities signal in putamen

N

34 (blood)

Tarnopolsky et al. [8]

E1-2 (proband's brother)

M

Caucasian

49y

19y

LHON

Visual loss, hearing loss

NP

NP

18 (blood)

Tarnopolsky et al. [8]

E1-3 (proband's brother)

M

Caucasian

56y

?

-

Visual changes, hearing loss, muscle weakness.

NP

NP

21 (blood)

Tarnopolsky et al. [8]

E1-4 (proband's mother)

F

Caucasian

78y

76y

-

Stroke episodes.

CT: hipodensity in right frontal periventricular region

NP

4 (blood)

Tarnopolsky et al. [8]

E2

M

Caucasian

17y

16y

LHON

Optic nerve pallor, visual loss.

MRI: normal

NP

26 (blood)