2-219210375-C-T

Position:

• chr2-219210375-C-T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_005689.4(ABCB6):​c.2351+6G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000477 in 1,614,142 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00015 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000037 (0 hom.)
• Consequence: ABCB6 NM_005689.4 splice_region, intron
• Scores: Splicing: ADA: 0.0001977
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0630

Genes affected

ABCB6 (HGNC:47): (ATP binding cassette subfamily B member 6 (LAN blood group)) This gene encodes a member of the ATP-binding cassette (ABC) transporter superfamily. ABC proteins transport various molecules across extra- and intra-cellular membranes. This protein is a member of the heavy metal importer subfamily and plays a role in porphyrin transport. This gene is the molecular basis of the Langereis (Lan) blood group antigen and mutations in this gene underlie familial pseudohyperkalemia and dyschromatosis universalis hereditaria. [provided by RefSeq, Mar 2017]

ENSG00000284820 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.63).
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000151 (23/152256) while in subpopulation AMR AF= 0.00144 (22/15286). AF 95% confidence interval is 0.000973. There are 0 homozygotes in gnomad4. There are 14 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd4 at 23 AD,BG gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABCB6	NM_005689.4	c.2351+6G>A		splice_region_variant, intron_variant		ENST00000265316.9	NP_005680.1
ABCB6	NM_001349828.2	c.2213+6G>A		splice_region_variant, intron_variant			NP_001336757.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABCB6	ENST00000265316.9	c.2351+6G>A		splice_region_variant, intron_variant		1	NM_005689.4	ENSP00000265316.3
ENSG00000284820	ENST00000446716.5	n.*4135+6G>A		splice_region_variant, intron_variant		2		ENSP00000398528.1

Frequencies

GnomAD3 genomes AF: 0.000151 AC: 23 AN: 152256 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00144

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000477 AC: 12 AN: 251424 Hom.: 0 AF XY: 0.0000515 AC XY: 7 AN XY: 135884

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000231

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: 0.0000352

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000369 AC: 54 AN: 1461886 Hom.: 0 Cov.: 33 AF XY: 0.0000344 AC XY: 25 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000179

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: 0.0000396

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.000151 AC: 23 AN: 152256 Hom.: 0 Cov.: 32 AF XY: 0.000188 AC XY: 14 AN XY: 74382

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00144

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.000272

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 26, 2023

This sequence change falls in intron 17 of the ABCB6 gene. It does not directly change the encoded amino acid sequence of the ABCB6 protein. It affects a nucleotide within the consensus splice site. 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. This variant has not been reported in the literature in individuals affected with ABCB6-related conditions. This variant is present in population databases (rs375028287, gnomAD 0.02%). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.63
CADD	Benign	15
DANN	Benign	0.85

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00020
dbscSNV1_RF	Benign	0.072
SpliceAI score (max)		0.020		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: rs375028287; hg19: chr2-220075097;