Search

Objective The Friedewald equation is the commonly used method of low-density lipoprotein cholesterol (LDL-C) calculation, requiring reflex to direct LDL-C measurement when triglycerides (TG) ≥ 400 mg/dL. Recently formulated Sampson and extended Martin/Hopkins methods have been validated with TG up to 800 mg/dL and thus have the potential to replace direct LDL-C measurement. Given the growing prevalence of childhood dyslipidemia, the objective of this study was to compare Sampson and extended Martin/Hopkins methods of LDL-C calculation with the direct measurement in a pediatric cohort with 400 ≤ TG ≤ 799 mg/dL. Methods This study retrieved standard lipid panels and corresponding direct LDL-C measurements of 131 patients with 400 ≤ TG ≤ 799 mg/dL from a pediatric population. Following the application of Sampson and extended Martin/Hopkins calculations, calculated values were compared with direct LDL-C measurements using ordinary least squares linear regression analysis and bias plotting. Results Both Sampson and extended Martin/Hopkins LDL-C calculations exhibited a strong correlation with the direct measurements (Pearson r  = 0.89) in patients with 400 ≤ TG ≤ 800 mg/dL. Average percentages of bias of 45% and 21% were found between the direct LDL-C measurements and Sampson or extended Martin/Hopkins calculations, respectively.  Conclusion Both Sampson and extended Martin/Hopkins calculations are applicable as clinical alternatives of direct LDL-C measurement in pediatric patients given 400 ≤ TG ≤ 799 mg/dL. [ABSTRACT FROM AUTHOR]

Fumaric aciduria resulting from fumarate hydratase deficiency is a rare inherited disorder of the Krebs tricarboxylic acid cycle that is characterized by neurologic manifestations, a spectrum of brain abnormalities, and the excretion of fumaric acid in urine. We describe a 3 year old Sri Lankan boy who was referred at age 10 months with poor weight gain and hypotonia for further laboratory investigations. In addition to global developmental delay, there were noticeable dysmorphic features with a prominent forehead, low-set ears, micrognathia, and hypertelorism with persistent neutropenia. Urine organic acid assay revealed a massive elevation of fumaric acid on 2 occasions. Molecular analysis revealed a homozygous likely pathogenic missense variant, NM000143.3:c.1048C>T p. (Arg350Trp), in the FH gene, confirming the biochemical diagnosis. Our patient was the first patient in Sri Lanka molecularly diagnosed with fumaric aciduria. This case study highlights the importance of performing organic acid assays in children presenting with neurologic manifestations especially when these are suspected to have a metabolic basis. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Urine Organic Acid Analysis: Key Diagnostic Test for Fumaric Aciduria in a Sri Lankan Child."