case_images: PMC10893891_01
case_images: Patient s corneal opacity.
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case_images: PMC10893891_01_TACG-17-23-g0001.jpg
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case_images: Tangier disease because of corneal opacity without visual acuity alteration, but with progressive deterioration of night vision, since the age of 10 years. The patient appeared phenotypically healthy, except for the corneal opacity (Figure 1).
case_images: Temporal record of the patient's HDL-C levels. Red line corresponds to the minimum value of the clinical reference.
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case_images: PMC10893891_01_TACG-17-23-g0002.jpg
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case_images: Throughout her life she presented with chronic dyslipidemia characterized by persistently low HDL-C levels stood out, even down to 2.8 mg/dL (Figure 2), high levels of triglycerides (216 mg/dL) and low levels of Apo-A1 (34.6 mg/dL).
case_images: Pedigree information of the patient and Sanger sequencing electropherogram of both patient and her family.
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case_images: Two missense variants were found: c.368G>C (p.Arg123Pro) classified as pathogenic (criteria: PM2, PM5, PP3, PP2, PP5 according to the American College of Medical Genetics and Genomics, ACMG) and c.803G>A (p.Arg268His) classified as pathogenic (criteria: PS3, PP3, PM2, PM5, PP5, according to the ACMG) located in exons 3 and 6 of the LCAT gene, respectively (Figure 3). In addition to the patient, two of her male siblings are carriers of the variant located in exon 6 (Arg268His) (Figure 3).
case_images: PMC10893891_02
case_images: Visualization through PyMOL of the crystal structure of the human Lecithin-Cholesterol Acyltransferase (4X96 Protein Data Bank) reported by Glukhova et al 2015. Protein Data Bank accession number 4X96. Arginine residue 123 is visualized in blue and the purple residue corresponds to Arginine 268.
case_images: TACG-17-23-g0004.jpg
case_images: PMC10893891_02_TACG-17-23-g0004.jpg
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case_images: Using in silico prediction tools it was possible to determine that the region of the mutation corresponds to an LCAT conserved region (Figure 4) and SIFT predicts that the residue change has a deleterious effect on the function of the protein (0.018). HOPE predicts physicochemical changes in the protein and loss of internal and external interactions, since the amino acid change differs in size and charge with the new one (Figure 4).