Biochemical phenotype and its relationship to treatment in 16 individuals with PCCB c.1606A > G (p.Asn536Asp) variant propionic acidemia.

Mol Genet Metab

Clinic for Special Children, Strasburg, PA, USA; Department of Pediatrics, Penn Medicine-Lancaster General Hospital, Lancaster, PA, USA; Departments of Pediatrics and Molecular, Cell & Cancer Biology, University of Massachusetts School of Medicine, Worcester, MA, USA.

Published: November 2020

Propionic acidemia (PA) is caused by inherited deficiency of mitochondrial propionyl-CoA carboxylase (PCC) and results in significant neurodevelopmental and cardiac morbidity. However, relationships among therapeutic intervention, biochemical markers, and disease progression are poorly understood. Sixteen individuals homozygous for PCCB c.1606A > G (p.Asn536Asp) variant PA participated in a two-week suspension of therapy. Standard metabolic markers (plasma amino acids, blood spot methylcitrate, plasma/urine acylcarnitines, urine organic acids) were obtained before and after stopping treatment. These same markers were obtained in sixteen unaffected siblings. Echocardiography and electrocardiography were obtained from all subjects. We characterized the baseline biochemical phenotype of untreated PCCB c.1606A > G homozygotes and impact of treatment on PCC deficiency biomarkers. Therapeutic regimens varied widely. Suspension of therapy did not significantly alter branched chain amino acid levels, their alpha-ketoacid derivatives, or urine ketones. Carnitine supplementation significantly increased urine propionylcarnitine and its ratio to total carnitine. Methylcitrate blood spot and urine levels did not correlate with other biochemical measures or cardiac outcomes. Treatment of PCCB c.1606A > G homozygotes with protein restriction, prescription formula, and/or various dietary supplements has a limited effect on core biomarkers of PCC deficiency. These patients require further longitudinal study with standardized approaches to better understand the relationship between biomarkers and disease burden.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ymgme.2020.09.006DOI Listing

Publication Analysis

Top Keywords

pccb c1606a > g
16
biochemical phenotype
8
c1606a > g pasn536asp
8
pasn536asp variant
8
propionic acidemia
8
suspension therapy
8
blood spot
8
c1606a > g homozygotes
8
pcc deficiency
8
biochemical
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!