NM_001139.3:c.2069T>C

Variant names:

• chr17-8072808-A-G
• rs760052556
• NM_001139.3:c.2069T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_001139.3(ALOX12B):​c.2069T>C​(p.Leu690Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: ALOX12B NM_001139.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.69

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.989
• PP5: Variant 17-8072808-A-G is Pathogenic according to our data. Variant chr17-8072808-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3701560.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALOX12B	NM_001139.3	c.2069T>C	p.Leu690Pro	missense_variant	Exon 15 of 15	ENST00000647874.1	NP_001130.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALOX12B	ENST00000647874.1	c.2069T>C	p.Leu690Pro	missense_variant	Exon 15 of 15		NM_001139.3	ENSP00000497784.1
ALOX12B	ENST00000649809.1	c.1133T>C	p.Leu378Pro	missense_variant	Exon 8 of 8			ENSP00000496845.1
ALOX12B	ENST00000650441.1	n.492T>C		non_coding_transcript_exon_variant	Exon 4 of 4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727248

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: 0.00000719

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

May 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 690 of the ALOX12B protein (p.Leu690Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with congenital ichthyosis (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ALOX12B protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.83	D;D;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	.;D;D
M_CAP	Pathogenic	0.56	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.8	H;H;.
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-6.1	D;.;.
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;.;.
Sift4G	Pathogenic	0.0010	D;.;.
Polyphen		1.0	D;D;.
Vest4		0.89
MutPred		0.89		Loss of stability (P = 0.0155);Loss of stability (P = 0.0155);.;
MVP		0.97
MPC		1.9
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.89
gMVP		0.99

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: rs760052556; hg19: chr17-7976126;