This report describes amyloidosis, familial visceral, LYZ-related, which is a subtype of familial visceral amyloidosis (see OMIM:105200); this disease exhibits autosomal dominant inheritance. The human gene implicated in this disease is lysozyme (LYZ), which is an antibacterial agent that catalyzes the hydrolysis of mucopolysaccharides of bacterial cell walls. There are multiple lysozymes in both human and in Drosophila. Modeling of LYZ-related amyloidosis in flies has been done using transgenic constructs of the human gene.
Multiple UAS constructs of the human Hsap\LYZ gene have been introduced into flies, including the soluble wild-type variant and several amyloidogenic lysozyme variants implicated in familial visceral amyloidosis. Using comparable transgenic insertions and GAL4 drivers, the wild-type variant is found at much higher levels in the hemolymph; high levels of expression of the wild-type form in all tissues results in pupal lethality. For the disease-implicated variants, but not for the wild-type human gene, expression in the adult eye results in a rough-eye phenotype; this provides a tractable system for further characterization.
Variant(s) implicated in human disease tested (as transgenic human gene, LYZ): F57I (F75I), D67H (D85H), and I56T (I74T) variant forms have been introduced into flies.
[updated Jan. 2019 by FlyBase; FBrf0222196]
A hereditary generalized amyloidosis in which viscera are particularly affected; there is no involvement of the nervous system. Clinical features include renal amyloidosis resulting in nephrotic syndrome, arterial hypertension, hepatosplenomegaly, cholestasis, petechial skin rash. (UniProt:P61626; 2016.07.29)
Lysozyme cleaves bacterial cell wall peptidoglycan; it is one of the antimicrobial agents found in human milk, and is also present in spleen, lung, kidney, white blood cells, plasma, saliva, and tears (Gene cards, LYZ; 2016.07.29).