A Dpagt1 Missense Variant Causes Degenerative Retinopathy without Myasthenic Syndrome in Mice.
Int J Mol Sci
; 23(19)2022 Oct 09.
Article
en En
| MEDLINE
| ID: mdl-36233305
ABSTRACT
Congenital disorders of glycosylation (CDG) are a heterogenous group of primarily autosomal recessive mendelian diseases caused by disruptions in the synthesis of lipid-linked oligosaccharides and their transfer to proteins. CDGs usually affect multiple organ systems and vary in presentation, even within families. There is currently no cure, and treatment is aimed at ameliorating symptoms and improving quality of life. Here, we describe a chemically induced mouse mutant, tvrm76, with early-onset photoreceptor degeneration. The recessive mutation was mapped to Chromosome 9 and associated with a missense mutation in the Dpagt1 gene encoding UDP-N-acetyl-D-glucosaminedolichyl-phosphate N-acetyl-D-glucosaminephosphotransferase (EC 2.7.8.15). The mutation is predicted to cause a substitution of aspartic acid with glycine at residue 166 of DPAGT1. This represents the first viable animal model of a Dpagt1 mutation and a novel phenotype for a CDG. The increased expression of Ddit3, and elevated levels of HSPA5 (BiP) suggest the presence of early-onset endoplasmic reticulum (ER) stress. These changes were associated with the induction of photoreceptor apoptosis in tvrm76 retinas. Mutations in human DPAGT1 cause myasthenic syndrome-13 and severe forms of a congenital disorder of glycosylation Type Ij. In contrast, Dpagt1tvrm76 homozygous mice present with congenital photoreceptor degeneration without overt muscle or muscular junction involvement. Our results suggest the possibility of DPAGT1 mutations in human patients that present primarily with retinitis pigmentosa, with little or no muscle disease. Variants in DPAGT1 should be considered when evaluating cases of non-syndromic retinal degeneration.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Enfermedades de la Retina
/
Trastornos Congénitos de Glicosilación
Tipo de estudio:
Etiology_studies
/
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Int J Mol Sci
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos