Impact of early diagnosis, disease variant, and quality of care on the neurocognitive outcome in maple syrup urine disease: A meta-analysis.

Purpose: Maple syrup urine disease (MSUD) is a rare inherited metabolic disease characterized by recurrent metabolic decompensations, neurocognitive impairment, and limited life expectancy. This meta-analysis aims to evaluate the impact of early diagnosis by newborn screening (NBS) on mortality and neurocognitive outcome in survivors, taking into account the quality of national health care systems.

Methods: Systematic literature search was performed according to Preferred Reporting Items for Systematic Review and Meta-Analysis protocol.

"Hide and seek": Misleading transferrin variants in PMM2-CDG complicate diagnostics.

Purpose: Congenital disorders of glycosylation (CDG) are one of the fastest growing groups of inborn errors of metabolism. Despite the availability of next-generation sequencing techniques and advanced methods for evaluation of glycosylation, CDG screening mainly relies on the analysis of serum transferrin (Tf) by isoelectric focusing, HPLC or capillary electrophoresis. The main pitfall of this screening method is the presence of Tf protein variants within the general population.

Delineating the clinical spectrum of isolated methylmalonic acidurias: cblA and mut.

Introduction: Long-term outcome is postulated to be different in isolated methylmalonic aciduria caused by mutations in the MMAA gene (cblA type) compared with methylmalonyl-CoA mutase deficiency (mut), but case definition was previously difficult.

Method: Cross-sectional analysis of data from the European Registry and Network for Intoxication type Metabolic Diseases (Chafea no. December 1, 2010).

Organic acidurias in adults: late complications and management.

Organic acidurias (synonym, organic acid disorders, OADs) are a heterogenous group of inherited metabolic diseases delineated with the implementation of gas chromatography/mass spectrometry in metabolic laboratories starting in the 1960s and 1970s. Biochemically, OADs are characterized by accumulation of mono-, di- and/or tricarboxylic acids ("organic acids") and corresponding coenzyme A, carnitine and/or glycine esters, some of which are considered toxic at high concentrations. Clinically, disease onset is variable, however, affected individuals may already present during the newborn period with life-threatening acute metabolic crises and acute multi-organ failure.

Maleic Acid--but Not Structurally Related Methylmalonic Acid--Interrupts Energy Metabolism by Impaired Calcium Homeostasis.

Maleic acid (MA) has been shown to induce Fanconi syndrome via disturbance of renal energy homeostasis, though the underlying pathomechanism is still under debate. Our study aimed to examine the pathomechanism underlying maleic acid-induced nephrotoxicity. Methylmalonic acid (MMA) is structurally similar to MA and accumulates in patients affected with methymalonic aciduria, a defect in the degradation of branched-chain amino acids, odd-chain fatty acids and cholesterol, which is associated with the development of tubulointerstitial nephritis resulting in chronic renal failure.