Table 1.

Phenotypic characterization of a family with NARP syndrome from the m.8993T>C ATPase 6 mutation

	Mother (Ml)	Daughter 1 (Dl)	Daughter 2 (D2)	Daughter 3 (D3)	Daughter 4 (D4)
Age (years)	48	28	26	22	16
Hair-bulb heteroplasmy (%)	87	99	54	99	99
Leukocyte heteroplasmy (%)	78	78	42	95	92
Clinical symptoms	RP, mild numbness, weakness, depression	Severe RP, moderate ataxia, neuropathy, weakness, depression	Remote history of depression with suicidal ideation	Severe ataxia, moderate RP, remote depression	Severe RP, episodic mild ataxia, mild depression
Neurological examination	Mild asymmetric weakness, absent triceps and S1 reflexes, decreased pain and vibration sense in the feet	Lingual dysarthria, moderate proximal weakness, mildly decreased vibration sense in the feet, moderate dysmetria, impaired tandem (straight line) gait	Normal	Nystagmus, saccadic breakdown, dysarthria, moderate weakness, spasticity, absent S1 reflex, dysmetria, tremor, impaired tandem (straight line) gait, decreased pain and vibration sense in the feet	Overshot saccades, mild proximal weakness, moderate dysmetria and dysdiadochokinesia, decreased S1 reflexes, decreased pain and vibration sense in the feet
EMG-NCS	Sensorimotor axonal polyneuropathy	Not done	Not done	Sensorimotor axonal polyneuropathy	Sensorimotor axonal polyneuropathy
MRI	Cystic/cavitary T2 hyperintensities in the bilateral putamina and globus pallidi, mild cerebellar atrophy, mild global volume loss	Cystic/cavitary T2 hyperintensities in bilateral putamina, anterior commissure, frontal gyrus recti, cerebellar atrophy	Mild T2 cystic/cavitary changes in basal ganglia	(Performed at age 18 years) Diffuse atrophy of cortex, cerebellum and cervical cord, T2 cystic/cavitary basal ganglia hyperintensities	Cystic/cavitary T2 hyperintensities in the anterior putamina and caudate heads, mild cerebellar atrophy
Neuropsychological testing	MMSE 29/30; selective impairments in information processing speed, set-shifting, and visual-spatial skills	MMSE 27/27 (excluding visual tasks); selective mild deficits in verbal fluency	MMSE 29/30; grossly normal with the exception of slightly variable information processing speed	MMSE 27/30; relative sparing of verbal abilities with impairments in motor speed, information processing speed, visual-spatial skills and memory	MMSE 30/30; selective impairments in motor speed, information processing speed, verbal fluency, and visual recall (despite adequate copy performance)
Mood	Moderate depression with suicidal ideation	Severe depression with moderate anxiety, despite antidepressant therapy; remote history of suicide attempt	Remote history of depression with suicidal ideation	Remote history of depression	Mild depression with severe anxiety
Best-corrected visual acuity	20/50	5/125	20/16	20/25	20/50
High-resolution optical coherence tomography	Moderate–severe photoreceptor layer thinning, with mild involvement of retinal nerve fiber layer	Severe foveal thinning, including photoreceptor layer, retinal pigment epithelial layer and retinal nerve fiber layer/ganglion cell layer	Not done	Patchy ring of photoreceptor/retinal nerve fiber layer thinning	Progressive thinning of the temporal photoreceptor/retinal nerve fiber layer

RP retinitis pigmentosa, MMSE mini-mental state examination