- Email: [email protected]
Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia
+
MODEL
Journal of the Formosan Medical Association (2016) xx, 1e3
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.jfma-online.com
CORRESPONDENCE
Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia Chia-Chieh Hsiao a, Ni-Chung Lee b,c, Pei-Hsin Huang d, Tzu-Hsun Tsai a,e,* a
Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan c Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan d Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan e Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan b
Received 18 February 2016; received in revised form 4 April 2016; accepted 7 April 2016
A 27-year-old woman with double vision and progressively outward deviation of the right eye for 20 years showed normal visual acuities and ocular findings in the ophthalmology examination. She had limitations in multiple directions of gaze, but no ptosis (Figure 1A). Krimsky I test showed exotropia of > 50D and right hypertropia of 45D. Laboratory findings were negative for antiacetylcholinereceptor, antinuclear, antimitochondrial, and antithyroglobulin antibodies. The comprehensive metabolic panel was within normal limits. Imaging study only showed atrophy of the extraocular muscles (EOMs). Chronic progressive external ophthalmoplegia (CPEO) was suspected; however, genetic testing using polymerase chain reaction (PCR) and restriction fragment length polymorphism showed no A8344G or A3243G gene mutations in the blood.
Conflicts of interest: The authors have no conflicts of interest relevant to this article. * Corresponding author. Department of Ophthalmology, National Taiwan University Hospital; College of Medicine, National Taiwan University, 12 F, Number 7, Zhongshan S. Road, Taipei, Taiwan. E-mail address: [email protected] (T.-H. Tsai).
The patient underwent strabismus surgeries, including recession of the right lateral rectus muscle by 9.5 mm and resections of the right medial and right inferior rectus muscles of 8.5 mm and 7.5 mm, respectively. Eye position measurement revealed right hypertropia of 12D postoperatively, with improved range of binocular single vision and appearance (Figure 1B). Histopathological examination of the EOM specimens showed generalized atrophic myocytes, increased central nucleation, and extensive endomysial fibrosis with hematoxylin and eosin staining (Figure 1C). Gomori trichrome staining revealed the presence of typical ragged-red fibers with sub-sarcolemmal accumulation (Figure 1D). Transmission electron microscopy showed abnormal mitochondria with aberrant fingerprint-like morphology and widened cristae with electron-dense accumulation (Figure 1E). Further genetic testing revealed a large 4977-bp deletion in the mitochondrial DNA (mtDNA) of the EOM tissue but not in the blood, compatible with the diagnosis of CPEO (Figure 1F). CPEO, a mitochondrial disease characterized by bilateral ptosis and progressive extraocular muscle limitation in multiple directions of gaze, was first described in 1868 by
http://dx.doi.org/10.1016/j.jfma.2016.04.010 0929-6646/Copyright ª 2016, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article in press as: Hsiao C-C, et al., Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.04.010
+ 2
MODEL
C.-C. Hsiao et al.
Figure 1 (A) Clinical photographs of the patient show gaze paresis in multiple directions in the right eye; (B) improved range of motion in the right eye after two-step strabismus surgery; (CeE) histopathological examination of the extra-ocular muscle (EOM) biopsy; (C) microscopically, hematoxylin and eosin (H&E) staining shows marked variation in fiber size with generalized atrophic myocytes (arrow), increased central nucleation, discernible regenerative myocytes, and extensive endomysial fibrosis. No inflammatory cell infiltrate is seen; (D) gomori-trichrome stain shows the presence of ragged-red fibers with sub-sarcolemmal accumulation (arrow), seen as hematoxylin aggregates in H&E staining, suggesting mitochondrial myopathy; (E) transmission electron microscopy was performed on the EM-processed tissue showing characteristic myofibrils of the skeletal muscle. Abnormal mitochondria, including aberrant fingerprint-like morphology and widened cristae with electron-dense accumulation (arrow) is frequently observed; (F) polymerase chain reaction (PCR) analysis of samples from the EOM demonstrated a large 4977-bp deletion in the mitochondrial DNA, but not in the blood of the patient. Lane 1 Z blood sample from a healthy individual; Lane 2 Z blood sample from the patient; Lane 3 Z EOM DNA from the patient. EOM Z extra-ocular muscle; M Z maker; NC Z negative control; PC Z positive control.
Please cite this article in press as: Hsiao C-C, et al., Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.04.010
+
MODEL
Histopathological and genetic analysis of EOM in CPEO Von Graefe.1 As mitochondria are ubiquitous organelles, mtDNA or associated nuclear DNA mutations are associated with a wild range of multi-systemic disease. Multiple independent factors influence the clinical expression of a mutation, including tissue distribution, heteroplasmy level, and the organ’s dependence on oxidative metabolism. The most common mtDNA mutation is a single, large-scale deletion w 2e10 kb long; the deletion breakpoints are often flanked by short direct repeats.2 This mutation type is associated with particular phenotypes, including CPEO, Kearns-Sayre syndrome (KSS), and Pearson’s marrowpancreases syndrome. Unlike KSS, in which partially deleted mtDNAs are present in all examined tissues and mother-to-offspring transmission of rearranged mtDNA species might occur,3 deletion of mtDNA is found only in EOM in CPEO patients, implying that the mutation occurs after fertilization in the muscle lineage of the mesoderm.4 Therefore, chances of mother to offspring transmission are lower. Fresnel prisms, eyelid crutches, and surgery are modalities to improve double vision and lid droop in patients with CPEO. Modified surgical dosage of the EOM by exceeding the corrections suggested by standard strabismus tables were recommended to prevent recurrence.5
3 In conclusion, our case demonstrates that patients with CPEO may benefit from strabismus surgery both functionally and cosmetically, and that histopathological and genetic testing of EOM specimen is essential for confirming the diagnosis in patients with ophthalmoplegia.
References 1. Bau V, Zierz S. Update on chronic progressive external ophthalmoplegia. Strabismus 2005;13:133e42. 2. Damas J, Carneiro J, Gonc ¸alves J, Stewart JB, Samuels DC, Amorim A, et al. Mitochondrial DNA deletions are associated with non-B DNA conformations. Nucleic Acids Res 2012;40: 7606e21. 3. Chinnery PF, DiMauro S, Shanske S, Schon EA, Zeviani M, Mariotti C, et al. Risk of developing a mitochondrial DNA deletion disorder. Lancet 2004;364:592e6. 4. Schon EA, DiMauro S, Hirano M. Human mitochondrial DNA: roles of inherited and somatic mutations. Nat Rev Genet 2012;13: 878e90. 5. Sorkin JA, Shoffner JM, Grossniklaus HE, Drack AV, Lambert SR. Strabismus and mitochondrial defects in chronic progressive external ophthalmoplegia. Am J Ophthalmol 1997;123:235e42.
Please cite this article in press as: Hsiao C-C, et al., Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.04.010
MODEL
Journal of the Formosan Medical Association (2016) xx, 1e3
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.jfma-online.com
CORRESPONDENCE
Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia Chia-Chieh Hsiao a, Ni-Chung Lee b,c, Pei-Hsin Huang d, Tzu-Hsun Tsai a,e,* a
Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan c Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan d Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan e Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan b
Received 18 February 2016; received in revised form 4 April 2016; accepted 7 April 2016
A 27-year-old woman with double vision and progressively outward deviation of the right eye for 20 years showed normal visual acuities and ocular findings in the ophthalmology examination. She had limitations in multiple directions of gaze, but no ptosis (Figure 1A). Krimsky I test showed exotropia of > 50D and right hypertropia of 45D. Laboratory findings were negative for antiacetylcholinereceptor, antinuclear, antimitochondrial, and antithyroglobulin antibodies. The comprehensive metabolic panel was within normal limits. Imaging study only showed atrophy of the extraocular muscles (EOMs). Chronic progressive external ophthalmoplegia (CPEO) was suspected; however, genetic testing using polymerase chain reaction (PCR) and restriction fragment length polymorphism showed no A8344G or A3243G gene mutations in the blood.
Conflicts of interest: The authors have no conflicts of interest relevant to this article. * Corresponding author. Department of Ophthalmology, National Taiwan University Hospital; College of Medicine, National Taiwan University, 12 F, Number 7, Zhongshan S. Road, Taipei, Taiwan. E-mail address: [email protected] (T.-H. Tsai).
The patient underwent strabismus surgeries, including recession of the right lateral rectus muscle by 9.5 mm and resections of the right medial and right inferior rectus muscles of 8.5 mm and 7.5 mm, respectively. Eye position measurement revealed right hypertropia of 12D postoperatively, with improved range of binocular single vision and appearance (Figure 1B). Histopathological examination of the EOM specimens showed generalized atrophic myocytes, increased central nucleation, and extensive endomysial fibrosis with hematoxylin and eosin staining (Figure 1C). Gomori trichrome staining revealed the presence of typical ragged-red fibers with sub-sarcolemmal accumulation (Figure 1D). Transmission electron microscopy showed abnormal mitochondria with aberrant fingerprint-like morphology and widened cristae with electron-dense accumulation (Figure 1E). Further genetic testing revealed a large 4977-bp deletion in the mitochondrial DNA (mtDNA) of the EOM tissue but not in the blood, compatible with the diagnosis of CPEO (Figure 1F). CPEO, a mitochondrial disease characterized by bilateral ptosis and progressive extraocular muscle limitation in multiple directions of gaze, was first described in 1868 by
http://dx.doi.org/10.1016/j.jfma.2016.04.010 0929-6646/Copyright ª 2016, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article in press as: Hsiao C-C, et al., Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.04.010
+ 2
MODEL
C.-C. Hsiao et al.
Figure 1 (A) Clinical photographs of the patient show gaze paresis in multiple directions in the right eye; (B) improved range of motion in the right eye after two-step strabismus surgery; (CeE) histopathological examination of the extra-ocular muscle (EOM) biopsy; (C) microscopically, hematoxylin and eosin (H&E) staining shows marked variation in fiber size with generalized atrophic myocytes (arrow), increased central nucleation, discernible regenerative myocytes, and extensive endomysial fibrosis. No inflammatory cell infiltrate is seen; (D) gomori-trichrome stain shows the presence of ragged-red fibers with sub-sarcolemmal accumulation (arrow), seen as hematoxylin aggregates in H&E staining, suggesting mitochondrial myopathy; (E) transmission electron microscopy was performed on the EM-processed tissue showing characteristic myofibrils of the skeletal muscle. Abnormal mitochondria, including aberrant fingerprint-like morphology and widened cristae with electron-dense accumulation (arrow) is frequently observed; (F) polymerase chain reaction (PCR) analysis of samples from the EOM demonstrated a large 4977-bp deletion in the mitochondrial DNA, but not in the blood of the patient. Lane 1 Z blood sample from a healthy individual; Lane 2 Z blood sample from the patient; Lane 3 Z EOM DNA from the patient. EOM Z extra-ocular muscle; M Z maker; NC Z negative control; PC Z positive control.
Please cite this article in press as: Hsiao C-C, et al., Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.04.010
+
MODEL
Histopathological and genetic analysis of EOM in CPEO Von Graefe.1 As mitochondria are ubiquitous organelles, mtDNA or associated nuclear DNA mutations are associated with a wild range of multi-systemic disease. Multiple independent factors influence the clinical expression of a mutation, including tissue distribution, heteroplasmy level, and the organ’s dependence on oxidative metabolism. The most common mtDNA mutation is a single, large-scale deletion w 2e10 kb long; the deletion breakpoints are often flanked by short direct repeats.2 This mutation type is associated with particular phenotypes, including CPEO, Kearns-Sayre syndrome (KSS), and Pearson’s marrowpancreases syndrome. Unlike KSS, in which partially deleted mtDNAs are present in all examined tissues and mother-to-offspring transmission of rearranged mtDNA species might occur,3 deletion of mtDNA is found only in EOM in CPEO patients, implying that the mutation occurs after fertilization in the muscle lineage of the mesoderm.4 Therefore, chances of mother to offspring transmission are lower. Fresnel prisms, eyelid crutches, and surgery are modalities to improve double vision and lid droop in patients with CPEO. Modified surgical dosage of the EOM by exceeding the corrections suggested by standard strabismus tables were recommended to prevent recurrence.5
3 In conclusion, our case demonstrates that patients with CPEO may benefit from strabismus surgery both functionally and cosmetically, and that histopathological and genetic testing of EOM specimen is essential for confirming the diagnosis in patients with ophthalmoplegia.
References 1. Bau V, Zierz S. Update on chronic progressive external ophthalmoplegia. Strabismus 2005;13:133e42. 2. Damas J, Carneiro J, Gonc ¸alves J, Stewart JB, Samuels DC, Amorim A, et al. Mitochondrial DNA deletions are associated with non-B DNA conformations. Nucleic Acids Res 2012;40: 7606e21. 3. Chinnery PF, DiMauro S, Shanske S, Schon EA, Zeviani M, Mariotti C, et al. Risk of developing a mitochondrial DNA deletion disorder. Lancet 2004;364:592e6. 4. Schon EA, DiMauro S, Hirano M. Human mitochondrial DNA: roles of inherited and somatic mutations. Nat Rev Genet 2012;13: 878e90. 5. Sorkin JA, Shoffner JM, Grossniklaus HE, Drack AV, Lambert SR. Strabismus and mitochondrial defects in chronic progressive external ophthalmoplegia. Am J Ophthalmol 1997;123:235e42.
Please cite this article in press as: Hsiao C-C, et al., Histopathological and genetic analysis of extraocular muscle in chronic progressive external ophthalmoplegia, Journal of the Formosan Medical Association (2016), http://dx.doi.org/10.1016/j.jfma.2016.04.010