Primary localized amyloidosis in one family

Area of Science:

• Medicine
• Genetics
• Pathology

Background:

• Primary localized amyloidosis is a rare condition characterized by amyloid deposition in specific organs or tissues without evidence of systemic disease.
• Familial occurrence of localized amyloidosis is uncommon, prompting further investigation into potential genetic factors.
• Amyloid protein AL, derived from immunoglobulin light chains, is a common type of amyloid associated with plasma cell dyscrasias, but can also occur in localized forms.

Observation:

• A 66-year-old woman presented with 18 years of hoarseness due to laryngeal amyloid deposits.
• Her 40-year-old daughter had a subcutaneous nodule on her philtrum with amyloid deposition in the dermis, encasing blood vessels and appendages.
• Both patients showed Congo red-positive amyloid resistant to potassium permanganate, indicating protein AL origin.

Findings:

• The amyloid deposits in both patients were strongly positive for lambda light chains, confirming an AL-type amyloidosis.
• Histopathological examination revealed amyloid deposition in the submucosal connective tissue of the larynx and in the dermis of the philtrum.
• No evidence of systemic amyloidosis or multiple myeloma was found in either patient, suggesting a primary localized form.

Implications:

• This familial case highlights a potential genetic link in primary localized amyloidosis, particularly AL-type.
• Understanding the genetic basis could lead to improved diagnostic strategies and targeted therapies for localized amyloidosis.
• Further research is warranted to identify specific genes or mutations associated with familial primary localized amyloidosis.