Hallazgos clínicos, bioquímicos y moleculares de la acidemia propiónica / Clinical, biochemical and molecular findings of propionic acidemia

La acidemia propiónica es un trastorno infrecuente con patrón de herencia autosómico recesivo causado por la deficiencia de la enzima mitocondrial propionil-CoA carboxilasa, que convierte el propionil-CoA a D-metilmalonil-CoA. Se expone el caso de un recién nacido masculino con signos de dificultad respiratoria, vómitos y cansancio durante la alimentación. Presentó acidosis metabólica, cuerpos cetónicos en el suero y la orina positivos, hiperamonemia, anemia, trombocitopenia e hipoproteinemia. El estudio bioquímico por cromatografía de gases acoplada a espectrometría de masas en la muestra de orina fue sugestivo de acidemia propiónica. El estudio molecular en el gen PCCA encontró las mutaciones c.893A>G (p.K298R) en el padre y c.937C>T (p.R313X) en la madre. Existe la necesidad de establecer el diagnóstico de esta entidad infrecuente para implementar las medidas terapéuticas disponibles y aportar el oportuno asesoramiento genético.

Propionic acidemia is an infrequent disorder with an autosomal recessive inheritance pattern caused by the deficiency of the mitochondrial enzyme propionyl-CoA carboxylase that converts propionyl-CoA to D-methylmalonyl-CoA. We present the case of a male newborn who showed signs of respiratory distress, vomiting and tiredness during feeding. He presented metabolic acidosis, positive serum and urine ketone bodies, hyperammonemia, anemia, thrombocytopenia and hypoproteinemia. The biochemical study by gas chromatography coupled to mass spectrometry in a urine sample was suggestive of propionic acidemia. The molecular study in the PCCA gene found the mutations c.893A>G (p.K298R) in the father and c.937C> T (p.R313X) in the mother. There is a need to establish the diagnosis of this infrequent entity to implement the therapeutic measures available and provide the appropriate genetic counseling.

Genotype and clinical features of Korean patients with methylmalonic aciduria and propionic aciduria / 소아과

PURPOSE: Methylmalonic aciduria (MMA) and propionic aciduria (PA) are inborn errors in the catabolism of branched-chain amino acids. The study was undertaken to investigate the genotypes and clinical features of Korean patients with MMA and PA. METHODS: This study examined 12 patients with MMA and eight with PA. We analyzed various clinical features, laboratory findings, treatments, and neuro-developmental outcomes. Diagnoses were based on the presence of characteristic compounds detected by amino acid analysis in serum and organic acid analysis in urine. Mutation analysis was performed in the genes of MUT, MMAA, MMAB, and MMACHC for MMA and PCCA and PCCB for PA. RESULTS: Among the 20 patients, six patients were diagnosed before one month of age and nine patients were diagnosed after the newborn period. Five patients were diagnosed via a neonatal screening test. Patients with early-onset forms had more severe illness at presentation and generally poor outcomes. A favorable outcome was obtained in 55% patients; most of them were of a late-onset type or diagnosed by neonatal mass screening test without symptoms. Genotypes were confirmed in all patients with MMA. We detected 11 different mutations by MUT gene analysis in 10 patients, and three different mutations in MMACHC genes in two patients. PCCA and PCCB gene mutations were identified in 14 of the 16 alleles, in eight patients with PA. CONCLUSION: Organic aciduria is a fatal disease; however, better outcomes are expected whenever early diagnosis and prompt management are made possible. Mutation analysis is useful for confirming diagnoses and planning management strategies.

Genotype and clinical features of Korean patients with methylmalonic aciduria and propionic aciduria / 소아과

PURPOSE: Methylmalonic aciduria (MMA) and propionic aciduria (PA) are inborn errors in the catabolism of branched-chain amino acids. The study was undertaken to investigate the genotypes and clinical features of Korean patients with MMA and PA. METHODS: This study examined 12 patients with MMA and eight with PA. We analyzed various clinical features, laboratory findings, treatments, and neuro-developmental outcomes. Diagnoses were based on the presence of characteristic compounds detected by amino acid analysis in serum and organic acid analysis in urine. Mutation analysis was performed in the genes of MUT, MMAA, MMAB, and MMACHC for MMA and PCCA and PCCB for PA. RESULTS: Among the 20 patients, six patients were diagnosed before one month of age and nine patients were diagnosed after the newborn period. Five patients were diagnosed via a neonatal screening test. Patients with early-onset forms had more severe illness at presentation and generally poor outcomes. A favorable outcome was obtained in 55% patients; most of them were of a late-onset type or diagnosed by neonatal mass screening test without symptoms. Genotypes were confirmed in all patients with MMA. We detected 11 different mutations by MUT gene analysis in 10 patients, and three different mutations in MMACHC genes in two patients. PCCA and PCCB gene mutations were identified in 14 of the 16 alleles, in eight patients with PA. CONCLUSION: Organic aciduria is a fatal disease; however, better outcomes are expected whenever early diagnosis and prompt management are made possible. Mutation analysis is useful for confirming diagnoses and planning management strategies.