Clinical analysis of methylmalonic acidemia presented with hemolytic uremic syndrome in children / 中华实用儿科临床杂志

ABSTRACT

Objective:To understand clinical characteristics, treatment effects and prognosis of children with methylmalonic acidemia (MMA) presented with hemolytic uremic syndrome(HUS).Methods:The medical records of children with MMA were collected in Beijing Children′s Hospital, Capital Medical University from January 2012 to January 2019, the clinical manifestations, laboratory, imaging material, inspection results, renal pathological, gene analysis, treatment effect, and prognosis of MMA children with renal damage were analyzed, and were followed-up for 1-7 years.Results:Thirty cases were diagnosed as MMA with secondary renal damage.Eight cases(26.67%) showed as MMA-HUS.Age was from 1 month and 14 days to 12 years and 10 months old.There were 4 males and 4 females.The concentration of urine methylmalonic acid increased by 10-62 times.All were combined with hyperhomocysteine(HCY). The level of serum methylmalonic acid(1.5-11.8 mg/L), propylene carnitine(6.33-9.77 μmol/L)and the ratio of propylene /ethylene carnitine (0.24-0.29)were increased.Manifested as the mental and physical development retardation, anemia, jaundice, renal dysfunction, platelet reduction, hematuria, proteinuria in 8 cases, hypertension in 6 cases, frequent vomiting and convulsions in 2 cases.Two cases had a positive family history.Renal pathology showed that mesangial cells and mesangial matrix proliferation broadening, electron dense deposits no mesangial area, renal tubular epithelial cell swelling degeneration, immunofluorescence was negative.Two cases were genetically analyzed. One case was a CblC type MMACHC compound heterozygous mutation[c.80A>G(p.Q27R); c.217C>T(p.R73X)] and CblX type HCFC1 heterozygous mutation [c.3757G>A(p.R1253C)] double mutation; 1 case was a CblC type MMACHC compound heterozygous mutation[c.365A>T(p.H122L); c.609 G>A(p.W203X)]. Children diagnosed were treated with vitamin B 12, etc.Four cases of children gave up.The others, after treatment, were improved. Conclusions:MMA-HUS might be associated with multiple organ failure.Early diagnosis was the key, timely treatment could effectively control the disease, improve the prognosis.It should be followed up for ever.