1-93993103-C-T

Position:

• chr1-93993103-C-T

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_000350.3(ABCA4):​c.*134G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00306 in 1,190,572 control chromosomes in the GnomAD database, including 91 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.014 (55 hom., cov: 32)
  • Exomes 𝑓: 0.0014 (36 hom.)
• Consequence: ABCA4 NM_000350.3 3_prime_UTR
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7
• Conservation: PhyloP100: -3.13

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]

ACMG classification

Verdict is Benign. Variant got -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BP6: Variant 1-93993103-C-T is Benign according to our data. Variant chr1-93993103-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 298219.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0141 (2146/152148) while in subpopulation AFR AF= 0.0491 (2036/41508). AF 95% confidence interval is 0.0473. There are 55 homozygotes in gnomad4. There are 973 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 55 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABCA4	NM_000350.3	c.*134G>A		3_prime_UTR_variant	50/50	ENST00000370225.4	NP_000341.2
ABCA4	XM_047416704.1	c.*134G>A		3_prime_UTR_variant	49/49		XP_047272660.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABCA4	ENST00000370225.4	c.*134G>A		3_prime_UTR_variant	50/50	1	NM_000350.3	ENSP00000359245	P1

Frequencies

GnomAD3 genomes AF: 0.0141 AC: 2145 AN: 152030 Hom.: 56 Cov.: 32

Gnomad AFR AF: 0.0492

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00525

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.000208

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00633

Gnomad NFE AF: 0.000103

Gnomad OTH AF: 0.00909

GnomAD4 exome AF: 0.00144 AC: 1499 AN: 1038424 Hom.: 36 Cov.: 13 AF XY: 0.00121 AC XY: 643 AN XY: 531216

Gnomad4 AFR exome AF: 0.0482

Gnomad4 AMR exome AF: 0.00256

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000201

Gnomad4 FIN exome AF: 0.0000211

Gnomad4 NFE exome AF: 0.000122

Gnomad4 OTH exome AF: 0.00232

GnomAD4 genome AF: 0.0141 AC: 2146 AN: 152148 Hom.: 55 Cov.: 32 AF XY: 0.0131 AC XY: 973 AN XY: 74384

Gnomad4 AFR AF: 0.0491

Gnomad4 AMR AF: 0.00524

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.000208

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000103

Gnomad4 OTH AF: 0.00900

Alfa AF: 0.00317 Hom.: 15

Bravo AF: 0.0163

Asia WGS AF: 0.00231 AC: 8 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:2

Benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 05, 2018	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

Retinitis Pigmentosa, Recessive Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Stargardt Disease, Recessive Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

ABCA4-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Cone-Rod Dystrophy, Recessive Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Macular degeneration Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	0.32
DANN	Benign	0.83

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

Other links and lift over

dbSNP: rs76201551; hg19: chr1-94458659;