chr3-187235874-C-G

Variant names:

• chr3-187235874-C-G
• rs387906754
• NM_139125.4:c.1997G>C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_139125.4(MASP1):​c.1997G>C​(p.Gly666Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G666E) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MASP1 NM_139125.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.91

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 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-187235874-C-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MASP1	NM_139125.4	c.1997G>C	p.Gly666Ala	missense_variant	Exon 11 of 11	ENST00000296280.11	NP_624302.1
MASP1	NM_001879.6	c.1303+5607G>C		intron_variant	Intron 10 of 15	ENST00000337774.10	NP_001870.3
MASP1	NR_033519.2	n.1870G>C		non_coding_transcript_exon_variant	Exon 10 of 10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MASP1	ENST00000296280.11	c.1997G>C	p.Gly666Ala	missense_variant	Exon 11 of 11	1	NM_139125.4	ENSP00000296280.7
MASP1	ENST00000337774.10	c.1303+5607G>C		intron_variant	Intron 10 of 15	1	NM_001879.6	ENSP00000336792.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 66

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	26
DANN	Uncertain	1.0
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.1	D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-5.3	D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.92
MutPred		0.93		Loss of glycosylation at S664 (P = 0.0259);.;
MVP		0.94
MPC		0.58
ClinPred		1.0	D
GERP RS		5.9
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs387906754; hg19: chr3-186953662;