The Characteristics of Ultrastructural Findings of Muscle Biopsy from Early Onset Leigh Syndrome; the Proposal of Ultrastructural Diagnostic Criteria for Muscle Biopsy.
Dowhan Kim, Se Hoon Kim, Songmi Noh, Young-Mock Lee. Yonsei University Health System, Seoul, Republic of Korea
Background: Leigh syndrome, a devastating neurodegenerative disorder, can be broadly classified into two categories according to its onset -- early and late. There are no reliable morphological (ultrastructural) diagnostic criteria especially for early onset Leigh syndrome, probably reflecting a lack of sufficient chronological time to accumulate various morphologic alterations from mitochondrial dysfunction.
Design: To identify ultrastructural findings, which make it easier to diagnose early onset Leigh syndrome, from muscle biopsies, sixty-two cases clinically suspicious for Leigh syndrome are collected ranging in age from 0 to 10. Among many suggestions by Kyriacou, several categorical features (inflammatory cell infiltration, ragged red fiber, reticular pattern, increased glycogen, increase lipid, maximal longitudinal and transverse size, and presence of abnormal mitochondria, etc.) are selected to minimize inter- and intra-observer variations. Chi-square test and logistic regression are performed.
Results: The EM features including 'more than 3 layers of mitochondria in the subsarcolemmal area' and 'more than 2 layers of mitochondria in the intermyofibrillar area' were shown to be statistically significant in early onset Leigh syndrome group with specificity of 67% and sensitivity of 72%.
Conclusions: Several charateristical ultrastructural findings provided by this pilot study will be helpful to diagnose early onset Leigh syndrome.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 286, Wednesday Morning