methylmalonic acidemia: diagnosis and neuroimaging findings of this neurometabolic disorder (an iranian pediatric case series)

how to cite this article: karimzadeh p, jafari n, jabbehdari s, taghdiri mm, nemati h, saket s, alaee mr, ghofrani m, tonakebni sh. methylmalonic acidemia: diagnosis and neuroimaging findings of this neurometabolic disorder (an iranian pediatric case series). iran j child neurol. 2013 summer; 7(3): 63-66.   objective methylmalonic acidemia is one of the inborn errors of metabolism resulting in the accumulation of acylcarnitine in blood and increased urinary methylmalonic acid excretion. this disorder can have symptoms, such as neurological and gastrointestinal manifestations, lethargy, and anorexia. materials & methods the patients who were diagnosed as methylmalonic acidemia in the neurology department of mofid children’s hospital in tehran, iran, between 2002 and 2012 were included in our study. the disorder was confirmed by clinical findings, neuroimaging findings, and neurometabolic and genetic assessment in reference laboratory in germany. we assessed the age, gender, past medical history, developmental status, clinical manifestations, and neuroimaging findings of 20 patients with methylmalonic acidemia. results eighty percent of the patients were offspring of consanguineous marriages. half of the patients had failure to thrive (ftt) due to anorexia; 85% had history of developmental delay or regression, and 20% had refractory seizure, which all of them were controlled. the patients with methylmalonic acidemia were followed for approximately 5 years and the follow-up showed that the patients with early diagnosis had a more favorable clinical response in growth index, refractory seizure, anorexia, and neurodevelopmental delay. neuroimaging findings included brain atrophy, basal ganglia involvement (often in putamen), and periventricular leukomalacia. conclusion according to the results of this study, we suggest that early assessment and diagnosis have an important role in the prevention of disease progression and clinical signs. references: 1. trinh bc, melhem er, barker pb. multi-slice proton mr spectroscopy and diffusion-weighted imaging in methylmalonic acidemia: report of two cases and review of the literature. ajnr am j neuroradiol 2001;22(5):831-3. 2. mahoney mj, bick d. recent advances in the inherited methylmalonic acidemias. acta paediatr scand 1987;76(5):689-96. 3. radmanesh a, zaman t, ghanaati h, molaei s, robertson rl, zamaniaa. methylmalonic acidemia: brain imaging findings in 52 children and a review of the literature.pediatr radiol 2008 oct;38(10):1054-61. 4. cantani a. [methylmalonic acidemia: classification, diagnosis and therapy]. klinpadiatr 1983;195(6):388-93. 5. avery me, first lr, pediatric medicine, 2nd ed. williams & wilkins, waverly company; 1994. p.1075. 6. matsui sm, mahoney mj, resenberg le. the natural history of the inherited methylmalonic acidemias. n engl j med 1983;308(15):857-61. 7. holliday ma, barrat m, arner ed. pediatric nephrology, 3rd ed. william and wilkins 1994; p. 890. 8. soda h, yoshida i, aramaki s, kuriya n, aoki k, inokuchi t, et al. renal handling of methylmalonic acid in a uraemic patient with vitamin b12 unresponsive methylmalonica cidaemia. j inherit metab dis 1996;19(1):90-1. 9. imen m, hanene b, ichraf k, aida r, ilhem t, naziha k, et al. methylmalonic acidemia and hyperglycemia: an unusual association. brain dev 2012;34(2):113-4. 10. ma x, zhang y, yang y, liu x, yang z, bao x, et al. epilepsy in children with methylmalonic acidemia: electroclinical features and prognosis. brain dev 2011;33(9):790-5. 11. brismar j, ozand pt. ct and mr of the brain in disorders of the propionate and methylmalonatemetabolism. ajnr am j neuroradiol 1994;15(8):1459-73. 12. nicolaides p, leonard j, surtees r. neurological outcome of methylmalonic acidaemia. arch dis child 1998;78:508-12.