1.
Atypical hemolytic uremic syndrome induced by CblC subtype of methylmalonic academia: A case report and literature review.
Chen, M, Zhuang, J, Yang, J, Wang, D, Yang, Q
Medicine. 2017;(43):e8284
-
-
Free full text
-
Abstract
RATIONALE Methylmalonic acidemia (MMA) is a common organic acidemia, mainly due to methylmalonyl-CoA mutase (MCM) or its coenzyme cobalamin (VitB12) metabolic disorders. Cobalamin C (CblC) type is the most frequent inborn error of cobalamin metabolism; it can develop symptoms in childhood and often combine multisystem damage, which leads to methylmalonic acid, propionic acid, methyl citrate, and other metabolites abnormal accumulation, causing nerve, liver, kidney, bone marrow, and other organ damage. PATIENT CONCERNS A 4-year-old girl presented with paleness, fatigue, severe normochromic anemia, and acute kidney injury. DIAGNOSIS Based on severe normochromic anemia and acute kidney injury, renal biopsy showed membranous proliferative glomerular lesions and thrombotic microvascular disease, supporting the diagnosis of aHUS. Although the serum vitamin B12 was normal, further investigation found the concentration of urinary methylmalonic acid and serum homocysteine increased obviously, genetic analysis revealed a heterozygous MMACHC mutation (exonl: c. 80A >G, c. 609G >A). The final diagnosis was aHUS induced by inherited methylmalonic acidemia (MMACHC heterozygous mutation exonl: c. 80A >G, c. 609G >A). INTERVENTIONS The patient was treated with a 1mg vitamin B12 intramuscular injection daily for 4 days after which the dose was then adjusted to a 1mg intramuscular injection twice a week. At the same time, the girl was given levocarnitine, betaine, folic acid, along with supportive treatment. OUTCOMES After treated by vitamin B12 for 10 days, the patient condition significantly improved, Follow-up results showed complete recovery of hemoglobin and renal function. LESSONS Although the majority of MMA onset from neurological damage, our case illustrates that partial CblC-type MMA can onset with severe metabolic aHUS. On the basis of chronic thrombotic microangiopathy (TMA)-induced renal damage, it can be complicated by acute hemolytic lesions. MMA should be considered in those patients with unclear microangiopathic hemolytic anemia accompany significant megaloblastic degeneration in bone marrow. We should pay attention to the causes and adopt a reasonable treatment strategy.
2.
Novel NCCT gene mutations as a cause of Gitelman's syndrome and a systematic review of mutant and polymorphic NCCT alleles.
Reissinger, A, Ludwig, M, Utsch, B, Prömse, A, Baulmann, J, Weisser, B, Vetter, H, Kramer, HJ, Bokemeyer, D
Kidney & blood pressure research. 2002;(6):354-62
Abstract
BACKGROUND Gitelman's syndrome (GS) is characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria and these phenotypic features have been shown to be attributable to mutations in the gene encoding the thiazide-sensitive Na/Cl cotransporter (NCCT). Until now, 55 different mutations have been reported and most of the families affected with GS exhibit autosomal recessive inheritance. METHODS All 26 exons of the human NCCT gene were investigated in 2 German NCCT-deficient patients and their families. Mutation detection was performed by either direct automated sequencing of polymerase chain reaction (PCR)-amplified DNA products or by sequence analysis of cloned PCR products. RESULTS In a 47-year-old German GS female a novel non-conservative missense mutation (S314F) and a complex deletion/insertion in the NCCT gene were found to be associated with the disorder. A further novel non-conservative substitution (S402F) together with a frequently observed R209W exchange were found in a 19-year-old German GS female. CONCLUSIONS The observation of a compound heterozygote state in both females affected and the absence of a GS phenotype in their relatives carrying a single mutant allele is consistent with an autosomal recessive pattern of inheritance.