12-7061922-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3

The NM_001734.5(C1S):c.5+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.00000684 in 1,461,648 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: C1S NM_001734.5 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9992
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.15

Genes affected

C1S (HGNC:1247): (complement C1s) This gene encodes a serine protease, which is a major constituent of the human complement subcomponent C1. C1s associates with two other complement components C1r and C1q in order to yield the first component of the serum complement system. Defects in this gene are the cause of selective C1s deficiency. [provided by RefSeq, Mar 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
C1S	NM_001734.5	c.5+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000360817.10
C1S	NM_001346850.2	c.-289+5G>A		splice_donor_5th_base_variant, intron_variant
C1S	NM_201442.4	c.5+5G>A		splice_donor_5th_base_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C1S	ENST00000360817.10	c.5+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_001734.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461648 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 727142

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000252

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

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 20, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant has not been reported in the literature in individuals affected with C1S-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 2 of the C1S gene. It does not directly change the encoded amino acid sequence of the C1S protein. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.33
Cadd	Benign	19
Dann	Benign	0.92

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
SpliceAI score (max)		0.60		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.60		Position offset: -5

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555161328; hg19: chr12-7169226;