Atypical adult-onset methylmalonic acidemia and homocystinuria presenting as hemolytic uremic syndrome
Thrombotic microangiopathy (TMA) syndromes can be secondary to a multitude of different diseases. Most can be identified with a systematic approach and, when excluded, TMA is generally attributed to a dysregulation in the activity of the complement alternative pathways—atypical hemolytic uremic syndrome (aHUS). We present a challenging case of a 19-year-old woman who presented with thrombotic microangiopathy, which was found to be caused by methylmalonic acidemia and homocystinuria, a rare vitamin B12 metabolism deficiency. To our knowledge, this is the first time that an adult-onset methylmalonic acidemia and homocystinuria presents as TMA preceding CNS involvement.
KeywordsMethylmalonic aciduria and homocystinuria Thrombotic microangiopathy Vitamin B12 metabolism
Compliance with ethical standards
Conflict of interest
All the authors have declared no competing interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
Written informed consent was obtained from the patient for publication of this case report and any accompanying images.
- 1.Yu X-J, Yu F, Song D, Wang S-X, Song Y, Liu G, et al. Clinical and renal biopsy findings predicting outcome in renal thrombotic microangiopathy: a large cohort study from a single institute in China. Sci World J. 2014;2014:680502.Google Scholar
- 2.Fakhouri F, Zuber J, Frémeaux-Bacchi V, Loirat C. Haemolytic uraemic syndrome. Lancet. 2017;6736(17).Google Scholar
- 3.Fidalgo T, Martinho P, Pinto S, Oliveira C, Salvado AC, Borràs RN, et al. Combined study of ADAMTS13 and complement genes in the diagnosis of thrombotic microangiopathies using next-generation sequencing. Res Pract Thromb Haemost. 2017;(March):1–12.Google Scholar
- 5.Nogueira C, Marcao A, Rocha H, Sousa C, Fonseca H, Valongo C, et al. Molecular picture of cobalamin C/D defects before and after newborn screening era. J Med Screen. 2016;0(0):1–6.Google Scholar
- 7.Weisfeld-Adams JD, Morrissey MA, Kirmse BM, Salveson BR, Wasserstein MP, McGuire PJ, et al. Newborn screening and early biochemical follow-up in combined methylmalonic aciduria and homocystinuria, cblC type, and utility of methionine as a secondary screening analyte. Mol Genet Metab. 2010;99(2):116–23.CrossRefPubMedGoogle Scholar
- 14.Moll R, Davis B. Iron, vitamin B 12 and folate. Medicine (Baltimore). Elsevier Ltd; 2017;45(4):198–203.Google Scholar