Genetic Variant SAP18:p.Arg12Cys (chr13-21140586-C-T) – ACMG Classification: Likely_benign (-5 pts)

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4BS2

The NM_005870.5(SAP18):c.34C>T(p.Arg12Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000181 in 1,605,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 10/17 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

SAP18
NM_005870.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.27

Variant links:

Genes affected

SAP18 (HGNC:10530): (Sin3A associated protein 18) Histone acetylation plays a key role in the regulation of eukaryotic gene expression. Histone acetylation and deacetylation are catalyzed by multisubunit complexes. The protein encoded by this gene is a component of the histone deacetylase complex, which includes SIN3, SAP30, HDAC1, HDAC2, RbAp46, RbAp48, and other polypeptides. This protein directly interacts with SIN3 and enhances SIN3-mediated transcriptional repression when tethered to the promoter. A pseudogene has been identified on chromosome 2. [provided by RefSeq, Dec 2008]

SAP18 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.29167885).

BS2

High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SAP18	NM_005870.5 link	c.34C>T	p.Arg12Cys	missense_variant	Exon 1 of 4	ENST00000382533.9	NP_005861.2	O00422-2
SAP18	NM_001366643.2 link	c.-172C>T		5_prime_UTR_variant	Exon 1 of 5		NP_001353572.1
SAP18	NR_172492.1 link	n.468C>T		non_coding_transcript_exon_variant	Exon 1 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SAP18	ENST00000382533.9 link	c.34C>T	p.Arg12Cys	missense_variant	Exon 1 of 4	1	NM_005870.5	ENSP00000371973.4		O00422-2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152202

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000382

AC:

AN:

235834

Hom.:

AF XY:

0.0000391

AC XY:

AN XY:

127840

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000210

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000189

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000165

AC:

AN:

1453406

Hom.:

Cov.:

AF XY:

0.0000166

AC XY:

AN XY:

722390

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000137

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000118

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000153

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152202

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74350

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 12, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.34C>T (p.R12C) alteration is located in exon 1 (coding exon 1) of the SAP18 gene. This alteration results from a C to T substitution at nucleotide position 34, causing the arginine (R) at amino acid position 12 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.030

BayesDel_noAF

Benign

-0.28

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.016

T;T

Eigen

Uncertain

0.22

Eigen_PC

Uncertain

0.27

FATHMM_MKL

Uncertain

0.93

LIST_S2

Benign

0.70

.;T

M_CAP

Benign

0.053

MetaRNN

Benign

0.29

T;T

MetaSVM

Benign

-0.52

PrimateAI

Pathogenic

0.81

PROVEAN

Benign

-0.95

N;.

REVEL

Benign

0.10

Sift

Benign

0.099

T;.

Sift4G

Benign

0.11

T;T

Vest4

0.52

MVP

0.64

MPC

0.00065

ClinPred

0.40

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.47

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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