chr20-18525021-G-T

Variant names:

• chr20-18525021-G-T
• rs398124226
• NM_006363.6:c.689+1G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_006363.6(SEC23B):​c.689+1G>T variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SEC23B NM_006363.6 splice_donor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.17
• Publications: 0 publications found

Genes affected

SEC23B (HGNC:10702): (SEC23 homolog B, COPII coat complex component) The protein encoded by this gene is a member of the SEC23 subfamily of the SEC23/SEC24 family, which is involved in vesicle trafficking. The encoded protein has similarity to yeast Sec23p component of COPII. COPII is the coat protein complex responsible for vesicle budding from the ER. The function of this gene product has been implicated in cargo selection and concentration. Multiple alternatively spliced transcript variants have been identified in this gene. [provided by RefSeq, Feb 2010]

SEC23B Gene-Disease associations (from GenCC):

• congenital dyserythropoietic anemia type 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, G2P, PanelApp Australia, Laboratory for Molecular Medicine
• Cowden disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Cowden syndrome 7

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• congenital dyserythropoietic anemia

  Inheritance: AR Classification: LIMITED Submitted by: Genomics England PanelApp

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 20-18525021-G-T is Pathogenic according to our data. Variant chr20-18525021-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 2939603.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006363.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SEC23B	NM_006363.6	MANE Select	c.689+1G>T		splice_donor intron	N/A	NP_006354.2
	SEC23B	NM_001172745.3		c.689+1G>T		splice_donor intron	N/A	NP_001166216.1	Q15437
	SEC23B	NM_032985.6		c.689+1G>T		splice_donor intron	N/A	NP_116780.1	Q15437

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SEC23B	ENST00000650089.1	MANE Select	c.689+1G>T		splice_donor intron	N/A	ENSP00000497473.1	Q15437
	SEC23B	ENST00000336714.8	TSL:1	c.689+1G>T		splice_donor intron	N/A	ENSP00000338844.3	Q15437
	SEC23B	ENST00000377465.6	TSL:1	c.689+1G>T		splice_donor intron	N/A	ENSP00000366685.1	Q15437

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Congenital dyserythropoietic anemia, type II;C4225179:Cowden syndrome 7 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.2
GERP RS		5.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -1

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

Other links and lift over

dbSNP: rs398124226; hg19: chr20-18505665;