Type 2 diabetes mellitus may be associated with a novel mitochondrial tRNAThr/tRNAPro mutation

Table 3 The pathogenic role of the m.C15954T mutation

Scoring criteria	m.C15954T mutation	Score/20	Classification
More than one independent report	No	0	≤ 6 points: Neutral polymorphisms; 7-10 points: Possibly pathogenic; 11-13 points (not including evidence from single fiber, steady-state level, or trans-mitochondrial cybrid studies): Probably pathogenic; ≥ 11 points (including evidence from single fiber, steady-state level or trans-mitochondrial cybrid studies): Definitely pathogenic
Evolutionary conservation of the base pair	No changes	2
Variant heteroplasmy	No	0
Segregation of the mutation with disease	Yes	2
Biochemical defect in complex I, III or IV	Yes	2
Evidence of mutation segregation with biochemical defect from single fiber studies	No evidence	0
Mutant mt-tRNA steady-state level or evidence of pathogenicity in trans-mitochondrial cybrid studies	Strong evidence	5
Maximum score	Definitely pathogenic	11

mt: Mitochondrial; tRNA: Transfer RNA.