chr19-5623216-C-T

Position:

• chr19-5623216-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_001201338.2(SAFB):​c.11C>T​(p.Thr4Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000226 in 1,594,724 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: SAFB NM_001201338.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.32

Genes affected

SAFB (HGNC:10520): (scaffold attachment factor B) This gene encodes a DNA-binding protein which has high specificity for scaffold or matrix attachment region DNA elements (S/MAR DNA). This protein is thought to be involved in attaching the base of chromatin loops to the nuclear matrix but there is conflicting evidence as to whether this protein is a component of chromatin or a nuclear matrix protein. Scaffold attachment factors are a specific subset of nuclear matrix proteins (NMP) that specifically bind to S/MAR. The encoded protein is thought to serve as a molecular base to assemble a 'transcriptosome complex' in the vicinity of actively transcribed genes. It is involved in the regulation of heat shock protein 27 transcription, can act as an estrogen receptor co-repressor and is a candidate for breast tumorigenesis. This gene is arranged head-to-head with a similar gene whose product has the same functions. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Jan 2011]

SAFB2 (HGNC:21605): (scaffold attachment factor B2) The protein encoded by this gene, along with its paralog (scaffold attachment factor B1), is a repressor of estrogen receptor alpha. The encoded protein binds scaffold/matrix attachment region (S/MAR) DNA and is involved in cell cycle regulation, apoptosis, differentiation, the stress response, and regulation of immune genes. [provided by RefSeq, May 2016]

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.09783873).
• BS2: High AC in GnomAdExome4 at 33 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SAFB	NM_001201338.2	c.11C>T	p.Thr4Ile	missense_variant	1/21	ENST00000588852.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SAFB	ENST00000588852.2	c.11C>T	p.Thr4Ile	missense_variant	1/21	1	NM_001201338.2	P5

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152240 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000233 AC: 5 AN: 214658 Hom.: 0 AF XY: 0.0000257 AC XY: 3 AN XY: 116840

Gnomad AFR exome AF: 0.0000792

Gnomad AMR exome AF: 0.0000654

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: 0.0000213

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000229 AC: 33 AN: 1442484 Hom.: 0 Cov.: 32 AF XY: 0.0000209 AC XY: 15 AN XY: 716298

Gnomad4 AFR exome AF: 0.0000304

Gnomad4 AMR exome AF: 0.0000486

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000238

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000236

Gnomad4 OTH exome AF: 0.0000335

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152240 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74378

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000416

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 22, 2023

The c.11C>T (p.T4I) alteration is located in exon 1 (coding exon 1) of the SAFB gene. This alteration results from a C to T substitution at nucleotide position 11, causing the threonine (T) at amino acid position 4 to be replaced by an isoleucine (I). 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
AlphaMissense	Benign	0.27
BayesDel_addAF	Benign	-0.36	T
BayesDel_noAF	Benign	-0.56
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.17	T;.;.;.
Eigen	Benign	-0.28
Eigen_PC	Benign	-0.12
FATHMM_MKL	Benign	0.62	D
LIST_S2	Benign	0.76	T;T;T;T
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.098	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.0	L;L;L;L
MutationTaster	Benign	1.0	D;N;N;N;N
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	-1.1	N;.;N;.
REVEL	Benign	0.035
Sift	Benign	0.054	T;.;T;.
Sift4G	Benign	0.18	T;T;T;T
Polyphen		0.0020	B;.;.;.
Vest4		0.22
MutPred		0.14		Gain of helix (P = 0.0128);Gain of helix (P = 0.0128);Gain of helix (P = 0.0128);Gain of helix (P = 0.0128);
MVP		0.20
MPC		2.1
ClinPred		0.29	T
GERP RS		2.8
Varity_R		0.11
gMVP		0.22

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

Other links and lift over

dbSNP: rs1246757204; hg19: chr19-5623227;