Retinal disorders
Gene: IMPG1The mode of inheritance of this gene has been updated following NHS Genomic Medicine Service approval.Created: 8 Mar 2022, 10:43 a.m. | Last Modified: 8 Mar 2022, 10:48 a.m.
Panel Version: 2.245
Comment on mode of inheritance: There is sufficient evidence to support the pathogenicity of both mono- and biallelic variant in the context of retinal disorders - and therefore, the MOI should be changed from 'monoallelic' to 'both mono- and biallelic' at the next GMS panel update.Created: 6 Aug 2021, 3:07 p.m. | Last Modified: 6 Aug 2021, 3:07 p.m.
Panel Version: 2.200
Penetrance for gene IMPG1 was set to 'Incomplete' - asymptomatic heterozygous carriers of IMPG1 variants with normal clinical examinations have been observed (PMIDs: 23993198 and 32817297) indicating incomplete penetranceCreated: 6 Aug 2021, 3:04 p.m. | Last Modified: 6 Aug 2021, 3:04 p.m.
Panel Version: 2.199
- Manes, et al. 2013 (PMID: 23993198) identified 3 families with autosomal dominant vitelliform macular dystrophy (VMD), associated with a recurrent c.713T>G variant leading to p.Leu238Arg in IMPG1. Screening of IMPG1 in a cohort of VMD patients revealed 2 further families with either homozygous for the c.807+1G>T splice-site variant, or compound heterozygous for variants c.461T>C (p.Leu154Pro) and c.1519C>T (p.Arg507(∗)).
- Brandl et al. 2017 (PMID: 28644393) identified 2 unrelated childhood-onset VMD cases with a heterozygous c.713T>C (p.Leu238Pro) missense variant and a homozygous c.807+5G>A splice-site variant, respectively.
- González-Gómez et al. 2019 (PMID: 30589393) reported on a 41-year-old woman with gradual bilateral decrease of her visual acuity due to bull's eye maculopathy. Sequencing identified a heterozygous variant c.121+2T>C in the IMPG1 gene.
- Gupta et al. 2019 (PMID: 30688845) describe a 25-year-old female patient with symptomatic scotoma and vision decrease. Multifocal electroretinogram revealed slightly decreased retinal sensitivity in the central retina of the left eye. Genetic testing identified a heterozygous p.Leu154Pro mutation in the IMPG1 gene.
- Olivier et al. 2021 (PMID: 32817297) identified seven variants in IMPG1 (including five novel) in 11 families with VMD or retinitis pigmentosa (RP). 4 families were diagnosed with autosomal dominant RP, 2 families had autosomal recessive RP, while 5 families developed VMD in association with heterozygous IMPG1 variants. Notably, inter- and intrafamilial phenotypic variation was evident with some individuals presenting RP while others had VMD, despite harbouring the same IMPG1 variant. Knockdown of Impg1 in medaka fish resulted in a phenotype consistent with that observed in human patients, including a decreased length of rod and cone photoreceptor outer segments.Created: 6 Aug 2021, 2:58 p.m. | Last Modified: 6 Aug 2021, 2:58 p.m.
Panel Version: 2.196
Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Phenotypes
Macular dystrophy, vitelliform, 4, OMIM:616151; Retinitis pigmentosa, MONDO:0019200
Publications
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Phenotypes
Macular dystrophy, vitelliform, 4
Variants in this GENE are reported as part of current diagnostic practice
This gene is on the Manchester Genetic Retinal Degeneration Conditions panel (covers known genes for isolated progessive retinal degeneration, Leber congenital amaurosis, macular dystrophy, achromatopsia, congenital stationary night blindness as well as the two most common causes of syndromic blindess Usher and Bardet-Biedl syndromes and additional syndromes including Joubert, Senior-Loken, and Cohen syndrome.Created: 2 Jun 2016, 8:04 a.m.
Tag Q3_21_MOI was removed from gene: IMPG1.
Mode of inheritance for gene IMPG1 was changed from MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Gene: impg1 has been classified as Green List (High Evidence).
Gene: impg1 has been classified as Amber List (Moderate Evidence).
Mode of inheritance for gene: IMPG1 was changed from MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Penetrance for gene IMPG1 was set from to Complete Tag Q3_21_MOI tag was added to IMPG1.
Phenotypes for gene: IMPG1 were changed from Macular dystrophy, vitelliform, 4 to Macular dystrophy, vitelliform, 4, OMIM:616151; Retinitis pigmentosa, MONDO:0019200
Publications for gene: IMPG1 were set to
Source NHS GMS was added to IMPG1. Rating Changed from Green List (high evidence) to Green List (high evidence)
This gene has been classified as Green List (High Evidence).
Phenotypes for IMPG1 were set to Macular dystrophy, vitelliform, 4
IMPG1 was added to Posterior segment abnormalitiespanel. Sources: Expert list
IMPG1 was created by ellenmcdonagh