chr11-18269795-G-C

Variant names:

• chr11-18269795-G-C
• NM_199161.5:c.309G>C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_199161.5(SAA1):​c.309G>C​(p.Trp103Cys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SAA1 NM_199161.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.75

Genes affected

SAA1 (HGNC:10513): (serum amyloid A1) This gene encodes a member of the serum amyloid A family of apolipoproteins. The encoded preproprotein is proteolytically processed to generate the mature protein. This protein is a major acute phase protein that is highly expressed in response to inflammation and tissue injury. This protein also plays an important role in HDL metabolism and cholesterol homeostasis. High levels of this protein are associated with chronic inflammatory diseases including atherosclerosis, rheumatoid arthritis, Alzheimer's disease and Crohn's disease. This protein may also be a potential biomarker for certain tumors. Finally, antimicrobial activity against S. aureus and E. coli resides in the N-terminal portion of the mature protein. Alternate splicing results in multiple transcript variants that encode the same protein. A pseudogene of this gene is found on chromosome 11. [provided by RefSeq, Jul 2020]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.918

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SAA1	NM_199161.5	c.309G>C	p.Trp103Cys	missense_variant	Exon 4 of 4	ENST00000356524.9	NP_954630.2
SAA1	NM_000331.6	c.309G>C	p.Trp103Cys	missense_variant	Exon 4 of 4		NP_000322.3
SAA1	NM_001178006.3	c.309G>C	p.Trp103Cys	missense_variant	Exon 5 of 5		NP_001171477.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SAA1	ENST00000356524.9	c.309G>C	p.Trp103Cys	missense_variant	Exon 4 of 4	1	NM_199161.5	ENSP00000348918.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Aug 26, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.309G>C (p.W103C) alteration is located in exon 4 (coding exon 3) of the SAA1 gene. This alteration results from a G to C substitution at nucleotide position 309, causing the tryptophan (W) at amino acid position 103 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.021	T
BayesDel_noAF	Benign	-0.27
CADD	Uncertain	25
DANN	Uncertain	0.98
DEOGEN2	Benign	0.21	T;T;T
Eigen	Uncertain	0.38
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Pathogenic	0.98	.;.;D
M_CAP	Benign	0.0098	T
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Benign	-0.92	T
PrimateAI	Uncertain	0.50	T
PROVEAN	Pathogenic	-9.8	D;D;D
REVEL	Benign	0.20
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0020	D;D;D
Vest4		0.67
MutPred		0.84		Loss of helix (P = 0.079);Loss of helix (P = 0.079);Loss of helix (P = 0.079);
MVP		0.31
MPC		0.042
ClinPred		1.0	D
GERP RS		2.6
gMVP		0.59

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-18291342;