ABSTRACT
Objective To investigate the clinical,biochemical and genetic findings in patients with isolated methylmalonic aciduria. Methods From January 2001 to December 2014,a total of 126 patients with isolated methyl-malonic aciduria from Peking University First Hospital were enrolled in this study. In 60 patients,gene analysis was per-formed. The clinical characteristics,laboratory findings,treatment and outcomes were retrospectively analyzed. Results Among the 126 patients,only 3 cases(2. 4% )were detected through newborn screening and treated with dietary in-tervention,cobalamin and L - camitine. The age at onset of 123 cases(97. 6% )varied from a few hours after birth to 7 years and 11 months old. The common presentations were recurrent vomiting,mental retardation,poor feeding,lethargy, respiratory distress,coma,seizures,cutaneous lesion and jaundice with 11 patients(8. 73% )dead. Abnormal family his-tory was found in 27(21. 4% )patients. Metabolic acidosis and anemia were frequent laboratory findings. Basal ganglia damage and white matter changes were observed in most patients. Sixty patients got genetic analysis,and 58 cases of them had MUT gene mutations. One case had MMAA defect. One case had MMAB defect. In MUT gene,12 novel muta-tions were identified. After treatment,mild to severe psychomotor retardation was observed in 112 patients with isolated methylmalonic aciduria. Conclusions The clinical manifestation of patients with isolated methylmalonic aciduria is complex,and prone to appear metabolic crisis. MUT defect is the main cause. Early metabolic investigation is very im-portant to reach diagnosis. Newborn screening,early diagnosis and adequate therapy are key points to reduce the morta-lity and handicap.
ABSTRACT
BACKGROUND: It is well known that severe hypoxemia is often associated with liver cirrhosis without preexisting cardiac or pulmonary diseases. Pulmonary vascular impairments, more specifically, intrapulmonary shunting have been considered as a major mechanism. Intrapulmonary shunting arises from pulmonary vascular dilatation at the precapillary level or direct arteriovenous communication and has relationship with the characteristic skin findings of spider angioma. However, these results are mainly from Western countries where alcoholic and primary biliary cirrhosis are dominant causes of cirrhosis. It is uncertain that tie same is true in viral hepatitiss associated liver cirrhosis, which is dominant causes of liver cirrhosis in Korea. We investigated the incidences of hypoxemia and orthodeoxia in Korean cirrhotic patients dominantly composed of postnecrotic cirrhosis and the significance of intrapulmonary shunting as the suggested mechanism of hypoxemia. METHOD: We performed the arterial blood gas analysis separately both at the supine and errect position in 48 stable cirrhotic patients without the evidences of severe complications such as ascites, variceal bleeding, and hepatic coma. According to the results of arterial blood gas analysis, all patients were divided into hypoxemic and normoxemic group. In each group, pulmonary function test and Tc-99m-MAA whole body scan were performed. The shunting fraction was calculated based on the fact that the sum of cerebral and bilateral renal blood flow is 32% of the systemic blood flow. RESULTS: The hypoxemia of PaO2 less than 80 mmHg was observed in 9 patients(18.8%) and Orthodeoxia more than 10 mmHg was observed in 8 patients(16.7%). Hut there was no patient with significant hypoxemia of PaO2 less than 60 mmHg. PaO2 was significantly decreased in the patients with spider angioma than the patients without spider angioma and showed no correlation with the serologic type and severities of liver function test findings. Any parameters of pulmonary function test did not demonstrate the difference between normoxemic and hypoxemic group. But hypoxemic group showed significantly increased shunt fraction of 11.4+/-4.1% than normoxemic group of 4.1+/-2.0% (p<0.05). CONCLUSIONS: Hypoxemia is not infrequently observed complication in liver cirrhosis and intrapulmonary shunting is suggested to play a major role in the development of hypxemia. But there was no great likelihood of clinically significant hypoxemia in our domestic cirrhotic patients predominantly composed of postnecrotic type.