Familial Amyloid Polyneuropathy Type II

**Semantic type:** Disease or Syndrome

**Definition:** A subtype of hereditary transthyretin amyloidosis with polyneuropathy characterized by a course of disease with polyneuropathy beginning at the hands and frequent carpal tunnel syndrome operations. Originally thought to be the result of the same genetic mutation, it was determined that substitution of histidine for leucine at position 58 of the TTR gene (L58H) results in the Maryland/German variant, whereas substitution of serine for isoleucine at position 84 of transthyretin (I84S) results in the Indiana/Swiss variant. The Maryland/German variant is further distinguished from the Indiana/Swiss variant by a lack of vitreous opacities.

**Synonyms:** - Indiana-Maryland type amyloid polyneuropathy