12-8857300-G-C

Variant names:

• chr12-8857300-G-C
• rs773450242
• NM_144670.6:c.2985G>C

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_144670.6(A2ML1):​c.2985G>C​(p.Thr995Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. T995T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: A2ML1 NM_144670.6 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -2.04
• Publications: 0 publications found

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]

A2ML1 Gene-Disease associations (from GenCC):

• Noonan syndrome

  Inheritance: AD Classification: SUPPORTIVE, LIMITED, NO_KNOWN Submitted by: Genomics England PanelApp, ClinGen, Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 12-8857300-G-C is Benign according to our data. Variant chr12-8857300-G-C is described in ClinVar as Likely_benign. ClinVar VariationId is 2626061.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
A2ML1	NM_144670.6	c.2985G>C	p.Thr995Thr	synonymous_variant	Exon 24 of 36	ENST00000299698.12	NP_653271.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
A2ML1	ENST00000299698.12	c.2985G>C	p.Thr995Thr	synonymous_variant	Exon 24 of 36	1	NM_144670.6	ENSP00000299698.7
A2ML1	ENST00000541459.5	c.1635G>C	p.Thr545Thr	synonymous_variant	Exon 13 of 25	2		ENSP00000443174.1
A2ML1	ENST00000539547.5	c.1512G>C	p.Thr504Thr	synonymous_variant	Exon 13 of 25	2		ENSP00000438292.1
A2ML1	ENST00000545850.1	n.66G>C		non_coding_transcript_exon_variant	Exon 1 of 2	3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

Aug 29, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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	-0.84
CADD	Benign	0.39
DANN	Benign	0.33
PhyloP100		-2.0

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

Other links and lift over

dbSNP: rs773450242; hg19: chr12-9009896;