A new case of familial lecithin: cholesterol acyltransferase (LCAT) deficiency--paradoxical findings regarding LCAT mass and activity in 23 members of a family

Area of Science:

• Biochemistry
• Genetics
• Clinical Medicine

Background:

• Familial lecithin-cholesterol acyltransferase (LCAT) deficiency is a rare genetic disorder affecting lipid metabolism.
• LCAT plays a crucial role in high-density lipoprotein (HDL) maturation and cholesterol esterification.
• Understanding LCAT variations is vital for diagnosing and managing dyslipidemias.

Observation:

• A novel family case revealed two homozygotes with significantly reduced HDL-cholesterol and ester cholesterol ratio.
• LCAT mass and activity were markedly diminished in affected individuals.
• Apolipoprotein (Apo) A-I and ApoA-II levels were low, while ApoE levels tended to be elevated.

Findings:

• Two distinct LCAT abnormalities were identified within the family: low LCAT mass with normal activity, and low LCAT activity with normal mass.
• One homozygote presented with classic LCAT deficiency symptoms.
• The other homozygote, a vegetarian, exhibited corneal opacities and red blood cell deformities without proteinuria, suggesting a potentially modified prognosis with low-fat diets.

Implications:

• Dietary interventions, such as low-fat diets, may influence the clinical presentation and prognosis of LCAT deficiency.
• Identifying different LCAT abnormalities can aid in predicting disease severity and potential complications.
• Further research into genotype-phenotype correlations in LCAT deficiency is warranted.