Pathology of Tangier disease.

Area of Science:

• Biochemistry
• Genetics
• Pediatric Pathology

Background:

• Tangier disease is a rare genetic disorder characterized by severe deficiency of high-density lipoprotein (HDL) cholesterol.
• It results from mutations in the ABCA1 gene, leading to impaired cholesterol efflux from cells.
• Accumulation of cholesterol-laden macrophages (foam cells) is a hallmark of the disease.

Purpose of the Study:

• To describe two pediatric cases of Tangier disease from unrelated families.
• To report the first necropsy findings in a child with Tangier disease.
• To suggest optimal diagnostic methods for Tangier disease.

Main Methods:

• Clinical case description of two unrelated children with Tangier disease.
• Necropsy examination of one affected child.
• Plasma lipid analysis, including alpha-lipoprotein levels, in affected children and their parents.
• Histopathological examination of tissues from necropsy.

Main Results:

• Necropsy revealed extensive cholesterol-laden macrophages in tonsils, thymus, lymph nodes, and colon.
• Moderate infiltration was observed in pyelonephritic scars and ureter.
• Absence of alpha-lipoproteins in affected children and low levels in parents confirmed the diagnosis.
• Rectal biopsy is proposed as a preferred diagnostic site due to potentially scanty storage cells in other tissues like marrow, jejunum, and liver.

Conclusions:

• Tangier disease presents with characteristic lipid deposition in various organs.
• Necropsy findings provide detailed insight into the pathological distribution of foam cells.
• Plasma lipid studies and rectal biopsy are crucial for accurate diagnosis and differentiation from other lipid storage disorders.