chr1-94037145-C-G

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5

The NM_000350.3(ABCA4):c.3813G>C(p.Glu1271Asp) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000342 in 1,461,714 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in Lovd. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E1271G) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

ABCA4
NM_000350.3 missense, splice_region

Scores

Splicing: ADA: 1.000

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 5.03

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]

ABCA4 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000350.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-94037146-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 959438.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 1-94037145-C-G is Pathogenic according to our data. Variant chr1-94037145-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2202789.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ABCA4	NM_000350.3 link	c.3813G>C	p.Glu1271Asp	missense_variant, splice_region_variant	Exon 25 of 50	ENST00000370225.4	NP_000341.2	P78363Q6AI28
ABCA4	NM_001425324.1 link	c.3591G>C	p.Glu1197Asp	missense_variant, splice_region_variant	Exon 24 of 49		NP_001412253.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCA4	ENST00000370225.4 link	c.3813G>C	p.Glu1271Asp	missense_variant, splice_region_variant	Exon 25 of 50	1	NM_000350.3	ENSP00000359245.3		P78363

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461714

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727180

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:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Optic atrophy

Pathogenic:1

Jan 01, 2023

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Uncertain:1

Sep 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 1271 of the ABCA4 protein (p.Glu1271Asp). RNA analysis indicates that this missense change induces altered splicing and likely results in the loss of 2 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ABCA4-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this missense change results in the activation of a cryptic splice site in exon 25 (PMID: 29162642). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.56

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.29

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.42

T;D

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

1.0

D;D

M_CAP

Pathogenic

0.61

MetaRNN

Pathogenic

0.89

D;D

MetaSVM

Uncertain

-0.015

MutationAssessor

Benign

1.7

.;L

PrimateAI

Uncertain

0.62

PROVEAN

Uncertain

-2.7

.;D

REVEL

Pathogenic

0.90

Sift

Uncertain

0.0040

.;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

0.81

.;P

Vest4

0.93

MutPred

0.55

.;Loss of ubiquitination at K1275 (P = 0.1083);

MVP

0.92

MPC

0.44

ClinPred

1.0

GERP RS

5.4

Varity_R

0.81

gMVP

0.65

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

1.0

SpliceAI score (max)

0.92

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.92

Position offset: 0

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

Publications

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over