Clinical and molecular basis of hepatocerebral mitochondrial DNA depletion syndrome in Japan: evaluation of outcomes after liver transplantation | Orphanet Journal of Rare Diseases | Full Text

Clinical and molecular basis of hepatocerebral mitochondrial DNA depletion syndrome in Japan: evaluation of outcomes after liver transplantation | Orphanet Journal of Rare Diseases | Full Text

Clinical and molecular basis of hepatocerebral mitochondrial DNA depletion syndrome in Japan: evaluation of outcomes after liver transplantation

• Masaru Shimura, 
• Naomi Kuranobu, 
• Minako Ogawa-Tominaga, 
• Nana Akiyama, 
• Yohei Sugiyama, 
• Tomohiro Ebihara, 
• Takuya Fushimi, 
• Keiko Ichimoto, 
• Ayako Matsunaga, 
• Tomoko Tsuruoka, 
• Yoshihito Kishita, 
• Shuichiro Umetsu, 
• Ayano Inui, 
• Tomoo Fujisawa, 
• Ken Tanikawa, 
• Reiko Ito, 
• Akinari Fukuda, 
• Jun Murakami, 
• Shunsaku Kaji, 
• Mureo Kasahara, 
• Kazuo Shiraki, 
• Akira Ohtake, 
• Yasushi Okazaki & 
• Kei Murayama 

Orphanet Journal of Rare Diseases volume 15, Article number: 169 (2020) Cite this article

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Abstract

Background

Hepatocerebral mitochondrial DNA depletion syndrome (MTDPS) is a disease caused by defects in mitochondrial DNA maintenance and leads to liver failure and neurological complications during infancy. Liver transplantation (LT) remains controversial due to poor outcomes associated with extrahepatic symptoms. The purposes of this study were to clarify the current clinical and molecular features of hepatocerebral MTDPS and to evaluate the outcomes of LT in MTDPS patients in Japan.

Results

We retrospectively assessed the clinical and genetic findings, as well as the clinical courses, of 23 hepatocerebral MTDPS patients from a pool of 999 patients who were diagnosed with mitochondrial diseases between 2007 and 2019. Causative genes were identified in 18 of 23 patients: MPV17 (n = 13), DGUOK (n = 3), POLG (n = 1), and MICOS13 (n = 1). Eight MPV17-deficient patients harbored c.451dupC and all three DGUOK-deficient patients harbored c.143-307_170del335. The most common initial manifestation was failure to thrive (n = 13, 56.5%). The most frequent liver symptom was cholestasis (n = 21, 91.3%). LT was performed on 12 patients, including nine MPV17-deficient and two DGUOK-deficient patients. Among the 12 transplanted patients, five, including one with mild intellectual disability, survived; while seven who had remarkable neurological symptoms before LT died. Five of the MPV17-deficient survivors had either c.149G > A or c.293C > T.

Conclusions

MPV17 was the most common genetic cause of hepatocerebral MTDPS. The outcome of LT for MTDPS was not favorable, as previously reported, however, patients harboring MPV17 mutations associated with mild phenotypes such as c.149G > A or c.293C > T, and exhibiting no marked neurologic manifestations before LT, had a better prognosis after LT.