title: [Clinical studies on fifty-seven Chinese patients with combined methylmalonic aciduria and homocysteinemia].
abstract: OBJECTIVE
  Methylmalonic aciduria (MMA) is a common one of the congenital disorders of organic acids metabolism. Some of the patients with the disorder are complicated with homocysteinemia. Recently, gas chromatography-mass spectrometry (GCMS) has been used to diagnose MMA in China. However, the diagnosis of the patients with combined MMA and homocysteinemia is often delayed. In this study, the natural history, clinical features and outcome of 57 Chinese patients with combined MMA and homocysteinemia were investigated.
  
  
  METHODS
  From 1996 to 2006, 96 MMA patients from 16 provinces or cities were diagnosed in our hospital by urine organic acids analysis using GCMS. Homocysteinemia was found by serum and urine total homocysteine determination using a fluorescence polarization immunoassay.
  
  
  RESULTS
  Fifty-seven of the 96 MMA patients (59.4%, 32 males and 25 females) were found to have combined MMA and homocysteinemia. They had markedly increased urine methylmalonic acid, total serum homocysteine (81.5 to 226.5 micromol/L vs. normal range 4.5 to 12.4 micromol/L) and urine homocysteine (79.1 to 414.5 micromol/L vs. normal range 1.0 to 25.0 micromol/L). Thirteen (22.8%) of them presented with symptoms resembled hypoxic-ischemic encephalopathy in the neonatal period. Fourteen (24.6%) patients had the onset at the age of one month to 1 year with mental retardation, vomiting and epilepsy. Nine (15.8%) showed developmental delay, seizures, poor appetite or anemia from the age of 1 to 3 years. Eighteen (31.6%) had psycho-motor degeneration at the age of 6 to 15 years. Among them, 7 patients experienced multiple organ dysfunctions with liver dysfunction, hematuria, renal failure and peripheral neuropathy. Three (5.3%) patients developed progressive mental degeneration, motor disorders and anorexia at the ages of 16, 24 and 34 years. Eleven (19.3%) patients ultimately died; 5 (8.8%) of them were diagnosed postmortem. Forty-six (80.7%) patients were treated with vitamin B12, folic acid, L-carnitine and betaine supplementation and 11 (19.3%) of them recovered completely.
  
  
  CONCLUSIONS
  Combined MMA with homocysteinemia is a common form of MMA in China. The clinical spectrum of the patients varies from severe neonatal-onset forms with high mortality to milder forms with adult-onset. Serum or urine total homocysteine analysis is important for the deferential diagnosis of the patients with MMA.
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jin-qing
authors.initials: JQ
authors.lastname: Song
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Rong
authors.initials: R
authors.lastname: Yan
authors.forename: Jin-hua
authors.initials: JH
authors.lastname: Dong
authors.forename: Yan-ling
authors.initials: YL
authors.lastname: Yang
authors.forename: Lan-feng
authors.initials: LF
authors.lastname: Wang
authors.forename: Yu-wu
authors.initials: YW
authors.lastname: Jiang
authors.forename: Yue-hua
authors.initials: YH
authors.lastname: Zhang
authors.forename: Jiong
authors.initials: J
authors.lastname: Qin
authors.forename: Xi-ru
authors.initials: XR
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications*; D000740:Anemia / Q000150:complications / Q000378:metabolism; D002331:Carnitine / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008659:Metabolic Diseases / Q000097:blood* / Q000150:complications / Q000378:metabolism; D008764:Methylmalonic Acid / Q000652:urine*; D014570:Urologic Diseases / Q000150:complications / Q000378:metabolism; D014805:Vitamin B 12 / Q000494:pharmacology; D014803:Vitamin B Complex / Q000494:pharmacology; D055815:Young Adult
chemical_list: D006710:Homocysteine; D014803:Vitamin B Complex; D008764:Methylmalonic Acid; D014805:Vitamin B 12; D002331:Carnitine