rs201471607
Variant summary
Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1PM5PP5_Very_Strong
The NM_000350.3(ABCA4):c.2894A>G(p.Asn965Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000075 in 1,614,088 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N965D) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000350.3 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Pathogenic. Variant got 12 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
ABCA4 | ENST00000370225.4 | c.2894A>G | p.Asn965Ser | missense_variant | Exon 19 of 50 | 1 | NM_000350.3 | ENSP00000359245.3 | ||
ABCA4 | ENST00000649773.1 | c.2672A>G | p.Asn891Ser | missense_variant | Exon 18 of 19 | ENSP00000496882.1 |
Frequencies
GnomAD3 genomes AF: 0.0000788 AC: 12AN: 152202Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000135 AC: 34AN: 251332Hom.: 0 AF XY: 0.000125 AC XY: 17AN XY: 135826
GnomAD4 exome AF: 0.0000746 AC: 109AN: 1461886Hom.: 0 Cov.: 32 AF XY: 0.0000729 AC XY: 53AN XY: 727242
GnomAD4 genome AF: 0.0000788 AC: 12AN: 152202Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3AN XY: 74358
ClinVar
Submissions by phenotype
Severe early-childhood-onset retinal dystrophy Pathogenic:3
- -
Variant is located in a mutational hotspot where >50% of variants are pathogenic (PM1) + Homozygous allele count in gnomAD exomes and genomes are less than 0 (PM2). Other variants on this amino acid residue have been classified as pathogenic (PM5, p.Asn965Asp, p.Asn965Ile, p.Asn965Lys). REVEL score is 0.779 (PP3_mod). + Variant is found to be in trans with another pathogenic variant (PM3, internal data). Study has shown the variant affects the function of the protein (PS3, PMID:29145636) -
This sequence change is predicted to replace asparagine with serine at codon 965 of the ABCA4 protein, p.(Asn965Ser). The asparagine residue is moderately conserved (100 vertebrates, UCSC), and is located within the Walker A motif in the ATP binding cassette transporter 1 domain, critical for nucleotide phosphate binding (PMID: 29145636). There is a small physicochemical difference between asparagine and serine. The variant is present in a large population cohort at a frequency of 0.01%, which is consistent with recessive disease (rs201471607, 35/282,722 alleles, 0 homozygotes in gnomAD v2.1). It has been identified in the homozygous state and compound heterozygous with a second pathogenic allele in multiple cases with retinal disorders including Stargadt disease, fundus flavimaculatus, retinitis pigmentosa, cone-rod dystrophy, and Bull's eye maculopathy (PMID: 17982420 , 20647261). Further, a p.Asn965Ser knock-in mouse model recapitulates the phenotype of Stargardt disease patients and Abca4 knockout mice (PMID: 29145636). Multiple lines of computational evidence predict a deleterious effect for the missense substitution (6/7 algorithms). Based on the classification scheme RMH ACMG Guidelines v1.2.1, this variant is classified as PATHOGENIC. Following criteria are met: PM3_VeryStrong, PS3, PM1, PM2, PP3. -
not provided Pathogenic:3
ABCA4: PM3:Very Strong, PM1, PM2, PM5:Supporting, PS3:Supporting -
Published functional studies demonstrate a damaging effect with partial misfolding of the protein with mislocalization and low ATPase activity (Molday et al., 2018); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 9054934, 27739528, 28446513, 27939946, 28118664, 22968130, 25356976, 24453473, 24713488, 26780318, 28327576, 28704108, 29126757, 24097981, 21226556, 30204727, 29925512, 30718709, 30093795, 31456290, 32845050, 32845068, 32531858, 33732702, 32619608, 33090715, 33691693, 33301772, 33261146, 32244552, 17982420, 28559085, 29145636) -
This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 965 of the ABCA4 protein (p.Asn965Ser). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with ABCA4-related disease and/or Stargardt disease (PMID: 17982420, 25356976, 27739528, 28559085). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 236096). 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%. Experimental studies have shown that this missense change affects ABCA4 function (PMID: 22735453, 24097981, 29145636). For these reasons, this variant has been classified as Pathogenic. -
Retinal dystrophy Pathogenic:3
- -
- -
- -
Stargardt disease Pathogenic:2
- -
- -
Stargardt disease 3 Pathogenic:1
- -
Macular dystrophy Pathogenic:1
- -
Cone-rod dystrophy Pathogenic:1
- -
Retinitis pigmentosa 19 Pathogenic:1
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.021%). Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through protein truncation. The predicted truncated protein may be shortened by more than 10%. The variant has been reported at least twice as pathogenic without evidence for the classification (ClinVar ID: VCV000419605 /PMID: 21039602 /3billion dataset). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2 Pathogenic:1
PM2_Supporting+PM3_VeryStrong+PP3_Moderate -
Retinitis pigmentosa Pathogenic:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at