Long-term outcomes after liver transplantation for deoxyguanosine kinase deficiency: a single-center experience and a review of the literature

Deoxyguanosine kinase (DGUOK) deficiency is a well-known cause of hepatocerebral mitochondrial DNA depletion syndromes, which include a broad spectrum of clinical presentations. Affected patients often develop life-threatening liver failure, but the benefits of liver transplantation (LT) are controversial because of the frequently severe neurological involvement due to the underlying mitochondrial disease. We describe the long-term clinical course of 2 patients from our institution and provide an update on their outcomes after LT with this condition. Another 12 pediatric patients were identified through a systematic search of the literature. All 14 reported patients underwent transplantation in infancy despite mild to moderate neurological impairment in some cases. The 2 DGUOK-deficient patients from our center displayed liver failure and mild to moderate neurological involvement. At the time of this writing, they had been followed for 5 and 8 years after LT, both patients were alive, and they had only mild neurological symptoms. Three of the 12 patients identified through the literature review survived for a long time (17, 12, and 23 years); 8 died during early follow-up; and for 1 patient, no follow-up information was available. The 1-year survival rate was 64%; 36% survived for more than 5 years. The long-term survivors had good quality of life. In conclusion, although survival after LT for DGUOK deficiency is lower than survival after LT for other indications, a significant proportion of patients benefit from LT with long-term survival and a stable neurological situation despite initial neurological abnormalities. Nevertheless, a decision to carry out LT for patients with DGUOK deficiency remains difficult because neurological symptoms may occur and worsen after LT despite their absence before transplantation.