The LCAT gene, located on chromosome 16q22.1, spans 4.2 kb and comprises 6 exons and 5 introns2; mutations in this gene cause LCAT deficiency, a rare metabolic disorder with two syndromes: classic familial LCAT deficiency (FLD; OMIM no. 245900), characterized by a complete lack of enzyme activity, and fish-eye disease (FED; OMIM no. 136120), characterized by a partially defective enzyme, both inherited via an autosomal-recessive patterns.3 The gene discussed is LCAT; the disease is fish eye disease.