[Therapeutic approaches for patients with adult-onset type II citrullinemia (CTLN2): effectiveness of treatment with low-carbohydrate diet and sodium pyruvate].

Adult-onset type II citrullinemia (CTLN2) is an autosomal recessive disease characterized by highly elevated plasma levels of citrulline and ammonia due to the urea cycle dysfunction associated with citrin deficiency. Patients with CTLN2 show various neurological symptoms with hyperammonemia closely resembling those of hepatic encephalopathy. Since 1990, 26 CTLN2 patients (17 males and 9 females) have been admitted and treated at Shinshu University Hospital. Twelve of the 26 patients received living related partial liver transplantation (LRLT). After LRLT, neurological symptoms soon disappeared, and all patients returned to their previous social lives. Among the 14 patients that did not undergo LRLT, 6 died of intractable encephalopathy or the development of hepatic cancer, but 8 patients have had relatively good clinical courses (follow-up range 0.5-8 years) with oral intake of L-arginine and low-carbohydrate and relatively protein-rich diet. Six patients have been also given sodium pyruvate and the frequency of attacks of encephalopathy markedly decreased in 5 of 6 patients. Our observations indicated that liver transplantation is a very promising type of therapy but that other therapeutic approaches, including low-carbohydrate diet and pyruvate, are being established.