NM_000180.4:c.307G>A
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PP4PP1PM2_SupportingPM3_Strong
This summary comes from the ClinGen Evidence Repository: NM_000180.4(GUCY2D):c.307G>A (p.Glu103Lys) is a missense variant that is predicted to replace glutamic acid with lysine at position p.103. Another missense variant in the same codon, NM_000180.4(GUCY2D):c.308A>T (p.Glu103Val), has been reported in association with GUCY2D-related recessive retinopathy (PMID:21602930), and splicing prediction using SpliceAI did not strongly predict an effect on splicing due to either of these variants. However, this second variant has not yet been classified by the ClinGen LCA / eoRD VCEP, so PM5 is not met. This variant is present in gnomAD v.4.1.0 at a total allele frequency of 0.0001749, with 257 alleles / 1,469,548 total alleles, which is lower than the ClinGen LCA/eoRD VCEP PM2_Supporting threshold of <0.0004 (PM2_Supporting). This variant has been reported in at least 2 apparently unrelated probands with early-onset severe retinal dystrophy who were compound heterozygous with either the NM_000180.4(GUCY2D):c.2595del (p.Lys866fs) variant or the NM_000180.4(GUCY2D):c.91dup (p.Arg31fs) variant confirmed in trans, which were previously classified pathogenic by the ClinGen LCA/eoRD VCEP (2 points, PMID:29178642, PM3_Strong). The variant has been reported to segregate with childhood-onset severe retinal dystrophy through the proband plus 1 similarly affected relative, with the variant present in the compound heterozygous state (PMID:31704230, PP1). At least one proband harboring this variant exhibits a phenotype including diagnosis of LCA (0.5 pts), nystagmus (1 pt), visual acuity limited to light perception (1 pt) since birth (1 pt), flat ERG responses from both rods (0.5 pts) and cones (1 pt), high hypermetropia, being drawn to bright light, sluggish pupillary responses (0.5 pts), eye poking, and normal appearing fundus with some abnormality in the reflection from the inner limiting membrane at high magnification, which together are specific for GUCY2D-related recessive retinopathy (total 5.5 points, PMID:29178642, PP4). The computational predictor REVEL gives a score of 0.547, which is below the ClinGen LCA/eoRD VCEP threshold of ≥0.644 and does not predict a damaging effect on RetGC-1 protein function. Additionally, the splicing impact predictor SpliceAI gives a score of 0.00, which is below the ClinGen LCA/eoRD VCEP recommended threshold of ≥0.2 and does not strongly predict an impact on splicing. In summary, this variant meets the criteria to be classified as likely pathogenic for GUCY2D-related recessive retinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen LCA/eoRD VCEP: PM2_Supporting, PM3_Strong, PP1 and PP4. (VCEP specifications version 1.0.0; date of approval 01/22/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA226122/MONDO:0100453/167
Frequency
Consequence
NM_000180.4 missense
Scores
Clinical Significance
Conservation
Publications
- cone-rod dystrophyInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
- GUCY2D-related dominant retinopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- GUCY2D-related recessive retinopathyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- Leber congenital amaurosis 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- cone-rod dystrophy 6Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- night blindness, congenital stationary, type1iInheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- Leber congenital amaurosisInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- central areolar choroidal dystrophyInheritance: AR, AD Classification: SUPPORTIVE, LIMITED Submitted by: G2P, Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000180.4. You can select a different transcript below to see updated ACMG assignments.
Frequencies
GnomAD3 genomes AF: 0.0000329 AC: 5AN: 152004Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000269 AC: 2AN: 74364 AF XY: 0.0000232 show subpopulations
GnomAD4 exome AF: 0.000191 AC: 252AN: 1317544Hom.: 0 Cov.: 34 AF XY: 0.000198 AC XY: 129AN XY: 649942 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000329 AC: 5AN: 152004Hom.: 0 Cov.: 32 AF XY: 0.0000539 AC XY: 4AN XY: 74264 show subpopulations
Age Distribution
ClinVar
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at