Sudden Death with Cardiac Involvement in a Neonate with Carnitine-Acylcarnitine Translocase Deficiency.

A female neonate born with normal Apgar scores at 38+2 weeks of gestational age unexpectedly passed away within less than 30 hours after birth. The situation mirrors her brother's earlier demise within 24 hours post-delivery, suggesting a possible genetic disorder. A gross examination revealed widespread cyanosis and distinct yellowish changes on the cardiac ventricles. Histopathological analysis disclosed lipid accumulation in the liver, heart, and kidney. Tandem mass spectrometry detected elevated levels of 10 amino acids and 14 carnitines in cardiac blood. Trio-whole genome sequencing (Trio-WGS) identified the SLC25A20 c.199-10T>G mutation associated with carnitine-acylcarnitine translocase disease (CACTD), a type of fatty acid oxidation disorders (FAODs) with a potential for sudden death. Further validation of gene expression confirmed the functional deficiency of SLC25A20, ultimately diagnosing CACTD as the underlying cause of the neonate's demise. This case highlights the importance of prenatal metabolic and genetic screening for prospective parents and emphasizes the need for forensic doctors to integrate metabolomic and genomic investigations into autopsies for suspected inherited metabolic diseases.