Genetic Variant NM_001906.6:c.633C>T (chr16-75224707-C-T) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBP7

The NM_001906.6(CTRB1):c.633C>T(p.Gly211Gly) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,608,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 30)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

CTRB1
NM_001906.6 splice_region, synonymous

Scores

Clinical Significance

Uncertain significance no assertion criteria provided U:1

Conservation

PhyloP100: -5.65

Variant links:

Genes affected

CTRB1 (HGNC:2521): (chymotrypsinogen B1) This gene encodes a member of the serine protease family of enzymes and forms a principal precursor of the pancreatic proteolytic enzymes. The encoded preproprotein is synthesized in the acinar cells of the pancreas and secreted into the small intestine where it undergoes proteolytic activation to generate a functional enzyme. This CTRB1 gene is located head-to-head with the related CTRB2 gene. Some human populations have an alternate haplotype which inverts a 16.6 Kb region containing portions of intron 1, exon 1, and the upstream sequence of the CTRB1 and CTRB2 genes. In this inversion haplotype exon 1 and flanking sequence is swapped in CTRB1 and CTRB2. This inversion is associated with differential gene expression and increased risk for chronic pancreatitis. The GRCh38 assembly represents the minor allele for SNP rs8048956 of the CTRB1 gene. SNP rs8048956 in intron 1 of the CTRB2 gene is diagnostic for this inversion. This CTRB1 gene encodes distinct isoforms, some or all of which may undergo similar processing to generate the mature protein. [provided by RefSeq, Jan 2021]

CTRB1 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.67).

BP7

Synonymous conserved (PhyloP=-5.65 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTRB1	NM_001906.6 link	c.633C>T	p.Gly211Gly	splice_region_variant, synonymous_variant	Exon 7 of 7	ENST00000361017.9	NP_001897.4	P17538
CTRB1	NM_001329190.2 link	c.499C>T	p.Arg167*	stop_gained, splice_region_variant	Exon 6 of 6		NP_001316119.1	P17538

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CTRB1	ENST00000361017.9 link	c.633C>T	p.Gly211Gly	splice_region_variant, synonymous_variant	Exon 7 of 7	1	NM_001906.6	ENSP00000354294.4		P17538
CTRB1	ENST00000642378.1 link	n.-112C>T		upstream_gene_variant				ENSP00000493978.1		A0A2R8Y4E9

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000203

AC:

AN:

246224

Hom.:

AF XY:

0.0000375

AC XY:

AN XY:

133404

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000300

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000110

Gnomad SAS exome

AF:

0.0000332

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000898

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000117

AC:

AN:

1456646

Hom.:

Cov.:

AF XY:

0.0000166

AC XY:

AN XY:

724414

show subpopulations

Gnomad4 AFR exome

AF:

0.0000301

Gnomad4 AMR exome

AF:

0.0000230

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000757

Gnomad4 SAS exome

AF:

0.0000117

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000721

Gnomad4 OTH exome

AF:

0.0000333

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000434

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Malignant tumor of prostate

Uncertain:1

Science for Life laboratory, Karolinska Institutet

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.67

CADD

Benign

0.023

DANN

Benign

0.76

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over