3-187221104-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001879.6(MASP1):c.1840T>C(p.Cys614Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,796 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: MASP1 NM_001879.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.88

Genes affected

MASP1 (HGNC:6901): (MBL associated serine protease 1) This gene encodes a serine protease that functions as a component of the lectin pathway of complement activation. The complement pathway plays an essential role in the innate and adaptive immune response. The encoded protein is synthesized as a zymogen and is activated when it complexes with the pathogen recognition molecules of lectin pathway, the mannose-binding lectin and the ficolins. This protein is not directly involved in complement activation but may play a role as an amplifier of complement activation by cleaving complement C2 or by activating another complement serine protease, MASP-2. The encoded protein is also able to cleave fibrinogen and factor XIII and may may be involved in coagulation. A splice variant of this gene which lacks the serine protease domain functions as an inhibitor of the complement pathway. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Apr 2010]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MASP1	NM_001879.6	c.1840T>C	p.Cys614Arg	missense_variant	15/16	ENST00000337774.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MASP1	ENST00000337774.10	c.1840T>C	p.Cys614Arg	missense_variant	15/16	1	NM_001879.6	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.0000318 AC: 8 AN: 251326 Hom.: 0 AF XY: 0.0000442 AC XY: 6 AN XY: 135832

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000435

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461796 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727190

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000176

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 29, 2023

The c.1840T>C (p.C614R) alteration is located in exon 15 (coding exon 15) of the MASP1 gene. This alteration results from a T to C substitution at nucleotide position 1840, causing the cysteine (C) at amino acid position 614 to be replaced by an arginine (R). 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
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.53
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.49	T
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H
MutationTaster	Benign	1.0	D
PROVEAN	Pathogenic	-11	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.96		Gain of MoRF binding (P = 0.0067);
MVP		0.98
ClinPred		1.0	D
GERP RS		5.9
Varity_R		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: rs779648802; hg19: chr3-186938892;