[Familial amyloid polyneuropathy type IV (Finnish type)--a clinicopathological study]

Familial amyloid polyneuropathy type IV (Finnish type, FAP IV) is one form of hereditary generalized amyloidosis with autosomal dominant trait and is characterized clinically by a triad of corneal lattice dystrophy, caudal cranial neuropathy and various skin changes. The vast majority of the families with this disorder originated from Finland. We carried out a clinicopathological study of a large FAP IV kindred recently found in Japan. This family consisted of 73 members in 5 generations with 17 affected individuals and 7 of them (ages 45 to 73) were examined in detail. All patients showed typical clinical manifestations, lacking significant peripheral neuropathy in the limbs. However, autonomic dysfunctions including orthostatic fainting and dysuria were seen in 2 patients. Congophilic amyloid deposits were commonly observed in an aspiration biopsy of abdominal fat tissues, and noradrenergic nerve fibers of the rectal mucosa were reduced in one patient with autonomic symptoms. DNA analysis using PCR revealed a single base change (G to A) at nucleotide position 654 of the gelsolin gene in 7 patients and one asymptomatic individual. The clinical pictures and gene abnormality in this Japanese family are very similar to those reported in Finland. Moreover, this study added that autonomic nerves might be involved in FAP IV patients at the advanced stage.