rs61750146
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM5PP3_StrongPP5_Very_Strong
The NM_000350.3(ABCA4):c.4462T>C(p.Cys1488Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000932 in 1,609,386 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C1488F) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000350.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152248Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000820 AC: 2AN: 243976Hom.: 0 AF XY: 0.00000760 AC XY: 1AN XY: 131518
GnomAD4 exome AF: 0.00000961 AC: 14AN: 1457138Hom.: 0 Cov.: 31 AF XY: 0.00000966 AC XY: 7AN XY: 724272
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152248Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74380
ClinVar
Submissions by phenotype
not provided Pathogenic:4Other:1
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The C1488R pathogenic variant in the ABCA4 gene has been published previously in association with Stargardt disease (Lewis et al., 1999; Briggs et al., 2001; Webster et al., 2001). The variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. C1488R is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. Functional studies have shown that C1488R results in lowered ATPase activity compared to wild type (Sun et al., 2000). Missense variants in the same codon (C1488Y/F) and in nearby residues (P1486L, C1490Y) have been reported in the Human Gene Mutation Database in association with Stargardt disease (Stenson et al., 2014), supporting the functional importance of this region of the protein. -
This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 1488 of the ABCA4 protein (p.Cys1488Arg). 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 individual(s) with ABCA4-related conditions (PMID: 22449572, 28559085, 29555955, 29925512). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 99284). 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: 11017087). For these reasons, this variant has been classified as Pathogenic. -
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ABCA4: PM3:Very Strong, PM1, PM2, PM5, PP3, PS3:Supporting -
Retinal dystrophy Pathogenic:3
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Severe early-childhood-onset retinal dystrophy Pathogenic:2
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ABCA4-related disorder Pathogenic:1
The ABCA4 c.4462T>C variant is predicted to result in the amino acid substitution p.Cys1488Arg. This variant has been reported in multiple individuals with ABCA4-related retinal disease or Stargardts disease (for examples, see Lewis et al. 1999. PubMed ID: 9973280; Bertelsen et al 2014. PubMed ID: 24713488; Supplementary Table 1, Birtel et al 2018. PubMed ID: 29555955). Variants impacting the same amino acid have also been classified as pathogenic or likely pathogenic for ABCA4-related retinal disease (c.4463G>T, p.Cys1488Phe; ClinVar ID: 99286 and c.4463G>A, p.Cys1488Tyr; ClinVar ID: 99285). This variant is reported in 0.0024% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as pathogenic. -
Retinitis pigmentosa 19 Pathogenic:1
Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000099284, PMID:9973280, PS1_S). Different missense changes at the same codon have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000099285,VCV000099286, PMID:10958763,11328725, PM5_M). In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.93, 3CNET: 0.99, PP3_P). A missense variant is a common mechanism associated with Retinitis pigmentosa 19 (PP2_P). It is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.000011, PM2_M). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -
Cone-rod dystrophy 3 Pathogenic:1
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.Cys1488Tyr; p.Cys1488Phe) + REVEL score is 0.93 (PP3_mod) -
Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2 Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at