rs368846708
Variant summary
Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM5PP2PP3_ModeratePP5
The NM_000350.3(ABCA4):c.2875A>T(p.Thr959Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000137 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T959A) has been classified as Pathogenic.
Frequency
Consequence
NM_000350.3 missense
Scores
Clinical Significance
Conservation
Publications
- ABCA4-related retinopathyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- cone-rod dystrophy 3Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
- severe early-childhood-onset retinal dystrophyInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Ambry Genetics
- retinitis pigmentosa 19Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- cone-rod dystrophyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- retinitis pigmentosaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Stargardt diseaseInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 8 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| ABCA4 | ENST00000370225.4 | c.2875A>T | p.Thr959Ser | missense_variant | Exon 19 of 50 | 1 | NM_000350.3 | ENSP00000359245.3 | ||
| ABCA4 | ENST00000649773.1 | c.2653A>T | p.Thr885Ser | missense_variant | Exon 18 of 19 | ENSP00000496882.1 |
Frequencies
GnomAD3 genomes AF: 0.0000723 AC: 11AN: 152112Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000716 AC: 18AN: 251358 AF XY: 0.0000736 show subpopulations
GnomAD4 exome AF: 0.000144 AC: 210AN: 1461880Hom.: 0 Cov.: 32 AF XY: 0.000127 AC XY: 92AN XY: 727240 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000723 AC: 11AN: 152112Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5AN XY: 74298 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:2
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This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 959 of the ABCA4 protein (p.Thr959Ser). This variant is present in population databases (rs368846708, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of ABCA4-related conditions (PMID: 32531858). ClinVar contains an entry for this variant (Variation ID: 424902). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ABCA4 protein function with a positive predictive value of 95%. This variant disrupts the p.Thr959 amino acid residue in ABCA4. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10958763, 24097981). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Isolated macular dystrophy Pathogenic:1
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Severe early-childhood-onset retinal dystrophy Pathogenic:1
Criteria applied: PM3_STR,PM5_STR,PM1,PM2,PP3 -
Retinitis pigmentosa Pathogenic:1
Variant summary: ABCA4 c.2875A>T (p.Thr959Ser) results in a conservative amino acid change located in the ABC transporter-like, ATP-binding domain (IPR003439) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 7.2e-05 in 251358 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in ABCA4 causing Retinitis Pigmentosa (7.2e-05 vs 0.0014), allowing no conclusion about variant significance. c.2875A>T has been reported in the literature in an individual affected with retinal degeneration (example: Weisschuh_2020). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Different variants affecting the same codon have been classified as likely pathogenic/pathogenic (c.2876C>T(p.Thr959Ile, c.2875A>G(p.Thr959Ala), supporting the critical relevance of codon 959 to ABCA4 protein function. The following publications have been ascertained in the context of this evaluation (PMID: 31964843, 32531858). ClinVar contains an entry for this variant (Variation ID: 424902). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
ABCA4-related disorder Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at