rs775524204

chr17-8081189-T-C

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_001139.3(ALOX12B):c.353-2A>G variant causes a splice acceptor change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,826 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 Pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ALOX12B NM_001139.3 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 2.91

Genes affected

ALOX12B (HGNC:430): (arachidonate 12-lipoxygenase, 12R type) This gene encodes an enzyme involved in the conversion of arachidonic acid to 12R-hydroxyeicosatetraenoic acid. Mutations in this gene are associated with nonbullous congenital ichthyosiform erythroderma. [provided by RefSeq, Sep 2015]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• 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 17-8081189-T-C is Pathogenic according to our data. Variant chr17-8081189-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 437467.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALOX12B	NM_001139.3	c.353-2A>G		splice_acceptor_variant		ENST00000647874.1
LOC107985075	XR_001752778.2	n.1462T>C		non_coding_transcript_exon_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALOX12B	ENST00000647874.1	c.353-2A>G		splice_acceptor_variant			NM_001139.3	P1
	ENST00000399413.3	n.1428T>C		non_coding_transcript_exon_variant	2/2	1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152068 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250906 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135656

Gnomad AFR exome AF: 0.00

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: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461758 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727180

Gnomad4 AFR exome AF: 0.0000299

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 152068 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74274

Gnomad4 AFR AF: 0.00

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: 0.0000294

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive congenital ichthyosis 2 Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Institute for Human Genetics, University Medical Center Freiburg	Jan 07, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genomic Research Center, Shahid Beheshti University of Medical Sciences	May 03, 2020	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 21, 2022

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 437467). Disruption of this splice site has been observed in individuals with congenital ichthyosis (PMID: 33435499). This variant is present in population databases (rs775524204, gnomAD 0.0009%). This sequence change affects an acceptor splice site in intron 2 of the ALOX12B gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ALOX12B are known to be pathogenic (PMID: 16116617, 23621129, 31046801). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Benign	-0.12
Cadd	Pathogenic	26
Dann	Uncertain	0.98
Eigen	Pathogenic	0.74
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.84	D
MutationTaster	Benign	1.0	D
GERP RS		4.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.91		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.91		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs775524204; hg19: chr17-7984507;