A familial amyloid polyneuropathy - PAF - commonly known as paramyloidosis or foot disease was the first time in the area of Portuguese population in the area of Póvoa do Varzim, by the neurologist, Professor Corino de Andrade.
A PAF is associated with deposition in tissues - particularly the nerves - of a highly insoluble fibrillar substance called amyloid. Amyloid fibers are made up of subunits of a blood protein that carry thyroid hormones and Vitamin A.
In normal situations, a TTR circulating in the blood is soluble in the tissues; However, when certain TTR mutations occur that alter its structure, for reasons still unknown, this protein forms amyloid fibers in the tissues. The replacement of a single amino acid, from valine to methionine, in position 30 gives rise to TTR Met 30, which is a major mutated form of TTR in FM PAF in Portugal.
A mutation and transmission in an autosomal dominant way; If the progenitor to heterozygous carrier (almost all cases), a probability of a child also carries the mutation of 50%.
The Met 30 mutation occurs in different countries of the world, having its greater focus in Portugal, followed by Japan, Sweden, an island of Majorca, Brazil and Italy.
The disease has an age of onset between 25 and 35 years (it can occur after 50 years), it begins in the lower limbs, affecting a sensitivity to the stimuli (for example, thermal), a motor capacity, and is fatal, In 10 years.
Dr. Maria João Saraiva Director of the Amyloid Unit of the Institute of Molecular and Cellular Biology of the University of Porto