Lecithin-cholesterol acyltransferase deficiency with the finding of "zebra bodies": A diagnostic challenge in the context of suspected Fabry disease.

Lecithin-cholesterol acyltransferase (LCAT) deficiency is a rare autosomal recessive disorder resulting from mutations in the LCAT gene, which leads to abnormal lipoprotein metabolism. This results in markedly reduced high-density lipoprotein cholesterol and the accumulation of lipoprotein X, leading to renal, corneal, and hemolytic damage. Two clinical variants have been described: familial LCAT deficiency (FLD) and fish-eye disease (FED). We report the case of a 41-year-old male with a history of hypertension, tinnitus, and progressive hearing loss, who presented with bilateral corneal opacity since childhood. Laboratory studies revealed significant proteinuria (2.56 g/24 h), preserved renal function (creatinine 0.85 mg/dL), mild anemia (Hb 10.2 g/dL), and extremely low HDL cholesterol (1.3 mg/dL). Renal biopsy showed focal segmental glomerulosclerosis and mesangial expansion. Electron microscopy demonstrated concentric lamellar inclusions known as "zebra bodies," a finding typically associated with Fabry disease. However, α-galactosidase A activity was normal, and genetic testing for Fabry disease was negative. Further genetic analysis identified the variant c.757 p.(Gln253Argfs*11) in the LCAT gene, confirming the diagnosis of familial LCAT deficiency. This case highlights the importance of differentiating LCAT deficiency from Fabry disease, given their overlapping clinical and histological features. Moreover, it represents the first description of "zebra bodies" in LCAT deficiency, emphasizing the diagnostic complexity and the need for a multidisciplinary approach to ensure accurate diagnosis and appropriate management.