12-8845442-T-C

Position:

• chr12-8845442-T-C

Variant summary

Our verdict is Benign. Variant got -15 ACMG points: 0P and 15B. BP4_Moderate BP6_Very_Strong BP7 BS2

The NM_144670.6(A2ML1):​c.1477T>C​(p.Leu493=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000124 in 1,614,070 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00022 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00011 (1 hom.)
• Consequence: A2ML1 NM_144670.6 splice_region, synonymous
• Scores: Splicing: ADA: 0.01101
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:8
• Conservation: PhyloP100: 0.0150

Genes affected

A2ML1 (HGNC:23336): (alpha-2-macroglobulin like 1) This gene encodes a member of the alpha-macroglobulin superfamily. The encoded protein is thought to be an N-glycosylated monomeric protein that acts as an inhibitor of several proteases. It has been shown to form covalent interactions with proteases, and has been reported as the p170 antigen recognized by autoantibodies in the autoimmune disease paraneoplastic pemphigus (PNP; PMID:20805888). Mutations in these gene have also been associated with some cases of Noonan syndrome (NS; PMID:24939586) as well as some cases of otitis media (PMID:26121085). Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Aug 2015]

ACMG classification

Verdict is Benign. Variant got -15 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.35).
• BP6: Variant 12-8845442-T-C is Benign according to our data. Variant chr12-8845442-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 413820.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-8845442-T-C is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=0.015 with no splicing effect.
• BS2: High AC in GnomAd4 at 34 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
A2ML1	NM_144670.6	c.1477T>C	p.Leu493=	splice_region_variant, synonymous_variant	13/36	ENST00000299698.12	NP_653271.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
A2ML1	ENST00000299698.12	c.1477T>C	p.Leu493=	splice_region_variant, synonymous_variant	13/36	1	NM_144670.6	ENSP00000299698	P1

Frequencies

GnomAD3 genomes AF: 0.000223 AC: 34 AN: 152152 Hom.: 0 Cov.: 31

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: 0.00316

Gnomad NFE AF: 0.000162

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000104 AC: 26 AN: 249470 Hom.: 0 AF XY: 0.000118 AC XY: 16 AN XY: 135358

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000232

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000106

Gnomad OTH exome AF: 0.000825

GnomAD4 exome AF: 0.000114 AC: 166 AN: 1461800 Hom.: 1 Cov.: 30 AF XY: 0.000124 AC XY: 90 AN XY: 727204

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.000201

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000827

Gnomad4 OTH exome AF: 0.000199

GnomAD4 genome AF: 0.000223 AC: 34 AN: 152270 Hom.: 0 Cov.: 31 AF XY: 0.000201 AC XY: 15 AN XY: 74452

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: 0.000162

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000207 Hom.: 2

Bravo AF: 0.000261

EpiCase AF: 0.000109

EpiControl AF: 0.000178

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:6

Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 04, 2018	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Feb 01, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 19, 2023	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -

not specified Benign:2

Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 02, 2022	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 06, 2023	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.35
CADD	Benign	10
DANN	Benign	0.89

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.011
dbscSNV1_RF	Benign	0.034
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: rs200088686; hg19: chr12-8998038;