20-18543178-T-C
Variant summary
Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_StrongBS2
The NM_006363.6(SEC23B):c.1665+6T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000632 in 1,614,028 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_006363.6 splice_region, intron
Scores
Clinical Significance
Conservation
Publications
- congenital dyserythropoietic anemia type 2Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Laboratory for Molecular Medicine, G2P
- Cowden diseaseInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Cowden syndrome 7Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
- congenital dyserythropoietic anemiaInheritance: AR Classification: LIMITED Submitted by: Genomics England PanelApp
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ACMG classification
Our verdict: Benign. The variant received -8 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SEC23B | NM_006363.6 | c.1665+6T>C | splice_region_variant, intron_variant | Intron 14 of 19 | ENST00000650089.1 | NP_006354.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| SEC23B | ENST00000650089.1 | c.1665+6T>C | splice_region_variant, intron_variant | Intron 14 of 19 | NM_006363.6 | ENSP00000497473.1 |
Frequencies
GnomAD3 genomes AF: 0.000434 AC: 66AN: 152150Hom.: 1 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000450 AC: 113AN: 251368 AF XY: 0.000427 show subpopulations
GnomAD4 exome AF: 0.000653 AC: 954AN: 1461878Hom.: 2 Cov.: 32 AF XY: 0.000645 AC XY: 469AN XY: 727240 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000434 AC: 66AN: 152150Hom.: 1 Cov.: 32 AF XY: 0.000350 AC XY: 26AN XY: 74326 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
Has not been previously published as pathogenic or benign to our knowledge; In silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.
Congenital dyserythropoietic anemia, type II;C4225179:Cowden syndrome 7 Uncertain:1
This sequence change falls in intron 14 of the SEC23B gene. It does not directly change the encoded amino acid sequence of the SEC23B protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs371786580, gnomAD 0.08%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with SEC23B-related conditions. ClinVar contains an entry for this variant (Variation ID: 571371). 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. 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.
Congenital dyserythropoietic anemia, type II Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
SEC23B-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at