NM_001563.4(IMPG1):c.1519C>T (p.Arg507Ter) AND Macular dystrophy, vitelliform, 4

Significance: Pathogenic
ClinVar: RCV000149549

Variant: NM_001563.4(IMPG1):c.1519C>T (p.Arg507Ter)

Type: Variant
Allele: NM_001563.4(IMPG1):c.1519C>T (p.Arg507Ter) 171850
Type: single nucleotide variant
Location: Chr6: 75950867 - assembly GRCh38
Chr6: 76660584 - assembly GRCh37
References: dbSNP: 367576664
OMIM: 602870.0002


Disease: Macular dystrophy, vitelliform, 4


    In a French brother and sister with vitelliform macular dystrophy (VMD4; 616151), Manes et al. (2013) identified compound heterozygosity for a c.1519C-T transition in exon 13 of the IMPG1 gene, resulting in an arg507-to-ter (R507X) substitution, and a c.461T-C transition in exon 3, resulting in a leu154-to-pro (L154P; 602870.0003) substitution at a conserved residue. The L154P mutation was not found in public SNP databases, and the R507X mutation was found at low frequency (1/13,006 alleles) in the Exome Variant Server database. The sibs' asymptomatic father carried the nonsense mutation; DNA was unavailable from their deceased mother. In addition, 4 asymptomatic children were heterozygous for 1 of the mutations: on examination, the sister's son, who carried the L154P missense mutation, had a slight defect in the line between the inner and outer segments in the nasal parafovea of the left eye, whereas her daughter, who carried the R507X nonsense mutation, had normal funduscopy.