chr1-94014665-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PP3_ModeratePP5

The NM_000350.3(ABCA4):​c.5338C>G​(p.Pro1780Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000133 in 1,614,058 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. P1780S) has been classified as Uncertain significance.

Frequency

Genomes: š‘“ 0.00013 ( 0 hom., cov: 32)
Exomes š‘“: 0.00013 ( 0 hom. )

Consequence

ABCA4
NM_000350.3 missense

Scores

9
8
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7U:4

Conservation

PhyloP100: 10.0
Variant links:
Genes affected
ABCA4 (HGNC:34): (ATP binding cassette subfamily A member 4) The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intracellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ABC1 subfamily. Members of the ABC1 subfamily comprise the only major ABC subfamily found exclusively in multicellular eukaryotes. This protein is a retina-specific ABC transporter with N-retinylidene-PE as a substrate. It is expressed exclusively in retina photoreceptor cells, and the gene product mediates transport of an essental molecule, all-trans-retinal aldehyde (atRAL), across the photoreceptor cell membrane. Mutations in this gene are found in patients diagnosed with Stargardt disease, a form of juvenile-onset macular degeneration. Mutations in this gene are also associated with retinitis pigmentosa-19, cone-rod dystrophy type 3, early-onset severe retinal dystrophy, fundus flavimaculatus, and macular degeneration age-related 2. [provided by RefSeq, Sep 2019]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000350.3
PP3
MetaRNN computational evidence supports a deleterious effect, 0.896
PP5
Variant 1-94014665-G-C is Pathogenic according to our data. Variant chr1-94014665-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 7912.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=5, Uncertain_significance=5, Pathogenic=1}. Variant chr1-94014665-G-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ABCA4NM_000350.3 linkc.5338C>G p.Pro1780Ala missense_variant Exon 38 of 50 ENST00000370225.4 NP_000341.2 P78363Q6AI28
ABCA4NM_001425324.1 linkc.5116C>G p.Pro1706Ala missense_variant Exon 37 of 49 NP_001412253.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABCA4ENST00000370225.4 linkc.5338C>G p.Pro1780Ala missense_variant Exon 38 of 50 1 NM_000350.3 ENSP00000359245.3 P78363

Frequencies

GnomAD3 genomes
AF:
0.000131
AC:
20
AN:
152176
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000265
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000107
AC:
27
AN:
251452
Hom.:
0
AF XY:
0.000125
AC XY:
17
AN XY:
135890
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000211
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000133
AC:
194
AN:
1461882
Hom.:
0
Cov.:
32
AF XY:
0.000138
AC XY:
100
AN XY:
727240
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.0000374
Gnomad4 NFE exome
AF:
0.000169
Gnomad4 OTH exome
AF:
0.0000662
GnomAD4 genome
AF:
0.000131
AC:
20
AN:
152176
Hom.:
0
Cov.:
32
AF XY:
0.000135
AC XY:
10
AN XY:
74334
show subpopulations
Gnomad4 AFR
AF:
0.0000483
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000265
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000188
Hom.:
0
Bravo
AF:
0.000166
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000349
AC:
3
ExAC
AF:
0.000115
AC:
14
EpiCase
AF:
0.000164
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:7Uncertain:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Oct 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 1780 of the ABCA4 protein (p.Pro1780Ala). This variant is present in population databases (rs121909207, gnomAD 0.02%). This missense change has been observed in individual(s) with Stargardt disease (PMID: 10746567, 28559085). 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: 7912). 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%. For these reasons, this variant has been classified as Pathogenic. -

Jan 15, 2025
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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: 31964843, 20849526, 28559085, 35886001, 35120629, 10746567, 37771441, 34954332, 32531858) -

May 01, 2018
CeGaT Center for Human Genetics Tuebingen
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Severe early-childhood-onset retinal dystrophy Pathogenic:1Uncertain:2
Sep 04, 2018
Centogene AG - the Rare Disease Company
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 07, 2022
MGZ Medical Genetics Center
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 01, 2000
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Retinal dystrophy Pathogenic:1Uncertain:1
Jan 01, 2022
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dec 12, 2018
Blueprint Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Optic atrophy Pathogenic:1
Jan 01, 2022
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2 Pathogenic:1
May 06, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not specified Uncertain:1
Jun 06, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: ABCA4 c.5338C>G (p.Pro1780Ala) results in a non-conservative amino acid change located in the ABC-2 type transporter, transmembrane domain (IPR013525) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00011 in 251452 control chromosomes, predominantly at a frequency of 0.00021 within the Non-Finnish European subpopulation in the gnomAD database. This frequency is not significantly higher than estimated for a pathogenic variant in ABCA4 causing Stargardt Disease (0.00011 vs 0.0014), allowing no conclusion about variant significance. c.5338C>G has been reported in the literature as a compound heterozygous genotype in individuals affected with Stargardt Disease (e.g. Shroyer_2000, Stone_2017, Weisschuh_2020). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 35886001, 10746567, 28559085, 32531858). Seven submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=5) or pathogenic (n=1)/likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic until additional clinical and/or functional data becomes available. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.47
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Pathogenic
0.39
CADD
Pathogenic
26
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.67
D;D
Eigen
Pathogenic
0.87
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
1.0
D;D
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.90
D;D
MetaSVM
Uncertain
0.53
D
MutationAssessor
Pathogenic
3.3
.;M
PrimateAI
Uncertain
0.68
T
PROVEAN
Pathogenic
-7.4
.;D
REVEL
Pathogenic
0.90
Sift
Uncertain
0.0030
.;D
Sift4G
Benign
0.070
T;D
Polyphen
1.0
.;D
Vest4
0.94
MVP
0.98
MPC
0.46
ClinPred
0.97
D
GERP RS
4.7
Varity_R
0.83
gMVP
0.86

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs121909207; hg19: chr1-94480221; API