NM_000350.3:c.6226A>G

Variant names:

• chr1-94001914-T-C
• rs1553186509
• NM_000350.3:c.6226A>G

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000350.3(ABCA4):​c.6226A>G​(p.Lys2076Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K2076T) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ABCA4 NM_000350.3 missense
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 6.09
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• ABCA4-related retinopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• cone-rod dystrophy 3

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• severe early-childhood-onset retinal dystrophy

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Ambry Genetics
• retinitis pigmentosa 19

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• cone-rod dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Stargardt disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• age related macular degeneration 2

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 17 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 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 chr1-94001913-T-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3643820.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 578 curated pathogenic missense variants (we use a threshold of 10). The gene has 28 curated benign missense variants. Gene score misZ: -0.65813 (below the threshold of 3.09). Trascript score misZ: 1.3628 (below the threshold of 3.09). GenCC associations: The gene is linked to cone-rod dystrophy 3, retinitis pigmentosa 19, ABCA4-related retinopathy, severe early-childhood-onset retinal dystrophy, cone-rod dystrophy, Stargardt disease, retinitis pigmentosa.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.963
• PP5: Variant 1-94001914-T-C is Pathogenic according to our data. Variant chr1-94001914-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 438106.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000350.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCA4	NM_000350.3	MANE Select	c.6226A>G	p.Lys2076Glu	missense	Exon 45 of 50	NP_000341.2	P78363
	ABCA4	NM_001425324.1		c.6004A>G	p.Lys2002Glu	missense	Exon 44 of 49	NP_001412253.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCA4	ENST00000370225.4	TSL:1 MANE Select	c.6226A>G	p.Lys2076Glu	missense	Exon 45 of 50	ENSP00000359245.3	P78363
	ABCA4	ENST00000465352.1	TSL:5	n.642A>G		non_coding_transcript_exon	Exon 6 of 6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Congenital stationary night blindness (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	M
PhyloP100		6.1
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.99	D
Vest4		0.74
MutPred		0.83		Loss of methylation at K2076 (P = 0.0011)
MVP		0.98
MPC		0.40
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.90
gMVP		0.94
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1553186509; hg19: chr1-94467470;