Homozygosity for the E526V Mutation in Fibrinogen A Alpha-Chain Amyloidosis: The First Report

Table 1

Homozygous amyloidogenic variants reported in the literature.

Gene	Protein; variant	Sequence variant (mRNA)	Patients ()	Geographic origin/ethnicity	Reported phenotype	Clinical course	References
GSN	Asp187Asn; (p.Asp214Asn)	c.640G>A	2	Finland	CN, CLD, SC, CRF	Severe nephropathy	[12, 13]
TTR	Val30Met; (p.Val50Met)	c.148G>A	19	Japan; Spain; Sweden; Turkey	PN, AN, VO, GI, H, CN	Wide variability, from asymptomatic carriers to slightly more severe phenotypes with higher incidence rate and earlier onset than heterozygotes within the same family	[14–19]
	Leu58His; (p.Leu78His)	c.233T>G	1	American/German	PN, CMP	More rapid course of disease	[20]
	Phe64Leu; (p.Phe84Leu)	c.250T>C	1	Italy	PN, AN, CMP	More severe phenotype	[21]
	Val122Ile; (p.Val142Ile)	c.424G>A	24	African/American	CMP	Earlier age at onset and uncertain penetrance, particularly with respect to gender	[22, 23]

AN: autonomic neuropathy; CLD: corneal lattice dystrophy; CMP: cardiomyopathy; CN: cranial neuropathy; CRF: chronic renal failure; GI: gastrointestinal symptoms; H: heart conduction disturbance; PN: peripheral polyneuropathy; SC: skin changes; VO: vitreous opacities.