Table 1.

Summary of the clinical, radiological, and biological findings of the three patients

	Patient 1	Patient 2	Patient 3
Age of onset, y	11	10	5
Age of examination, y	15	54	33
Sex	Male	Female	Male
Race/ethnicity	Italian	Ashkenazi Jewish	Kuwaiti
First sign	Focal dystonia	Gait ataxia	Gait and limb ataxia
Ataxia	+	++	++
Cognition	Normal	Impaired	Impaired
Other findings	Axial tremor and dystonia, scoliosis	No	No
Tendon reflexes	Normal	Normal	Normal
Disease course	Progression for 10 years, then stabilize	Slowly progressive until the age of 40 then more rapid progression	Slowly progressive
Brain MRI	No cerebellar atrophy at age 25	Cerebellar atrophy at age 40	Severe cerebellar atrophy at age 33
NCV	Normal	Not available	Normal
Muscle CoQ10 level (ug/g) 1	22.38 (low)	14.54 (low)	15.91 (low)
Mutation	Compound heterozygous: c.901C>T (p.Arg301Trp), c.1399‐3_1408del	Compound heterozygous: c.1749_1751delCAC (p.Thr584del) in exon 14, c.1532C>T (p.Thr511Met) in exon 12	Homozygous, c.913G>T; p.D305Y, at exon 7

Abbreviations: CoQ₁₀, coenzyme Q10; MRI, magnetic resonance imaging; NCS, nerve conduction studies.

Reference range: ¹23.63–48.11 ug/g