Novel homozygous variant in ACSL5 gene causing Congenital Diarrhea and Enteropathy (CODE) with sustained therapeutic success: a case report.

BACKGROUND: Congenital Diarrhea and Enteropathies (CODEs) are rare monogenic disorders with early-onset diarrhea, feeding intolerance, and malabsorption causing secondary failure to thrive (FTT). ACSL5 deficiency is an emerging CODE subtype linked to defective intestinal fatty acid metabolism and dysregulated satiety signaling. CASE PRESENTATION: A female infant presented with chronic diarrhea, postprandial vomiting, and severe growth faltering. First-line evaluations were unrevealing. Proband-only whole-exome sequencing (WES) identified a novel homozygous missense variant in ACSL5, NM_016234.4:c.1748G > A, p.(Gly583Asp) (OMIM #620357), absent from population/clinical databases; in the context of consanguinity and fitting phenotype, findings supported ACSL5-related CODE. A medium-chain triglyceride (MCT)-enriched, low-fat diet started at 8 months led to resolution of gastrointestinal symptoms within weeks and sustained catch-up growth. At 4 years, the child was asymptomatic with weight/height around the 50th percentiles and normal development. CONCLUSIONS: This case broadens the clinical/variant spectrum of ACSL5-related enteropathy and highlights a dual mechanism, impaired intestinal long-chain fatty-acid activation with enteroendocrine dysregulation. Early exome sequencing and MCT-based nutrition can enable rapid symptom control and durable growth recovery.