chr4-87806127-T-G

Position:

• chr4-87806127-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004967.4(IBSP):​c.189T>G​(p.Ser63Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: IBSP NM_004967.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.833

Genes affected

IBSP (HGNC:5341): (integrin binding sialoprotein) The protein encoded by this gene is a major structural protein of the bone matrix. It constitutes approximately 12% of the noncollagenous proteins in human bone and is synthesized by skeletal-associated cell types, including hypertrophic chondrocytes, osteoblasts, osteocytes, and osteoclasts. The only extraskeletal site of its synthesis is the trophoblast. This protein binds to calcium and hydroxyapatite via its acidic amino acid clusters, and mediates cell attachment through an RGD sequence that recognizes the vitronectin receptor. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11771724).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IBSP	NM_004967.4	c.189T>G	p.Ser63Arg	missense_variant	5/7	ENST00000226284.7	NP_004958.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IBSP	ENST00000226284.7	c.189T>G	p.Ser63Arg	missense_variant	5/7	1	NM_004967.4	ENSP00000226284.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000113

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

Mar 14, 2024

The c.189T>G (p.S63R) alteration is located in exon 5 (coding exon 4) of the IBSP gene. This alteration results from a T to G substitution at nucleotide position 189, causing the serine (S) at amino acid position 63 to be replaced by an arginine (R). 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	0.30
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.68
CADD	Benign	7.1
DANN	Benign	0.96
DEOGEN2	Benign	0.10	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.098	N
LIST_S2	Benign	0.58	T
M_CAP	Benign	0.0048	T
MetaRNN	Benign	0.12	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.3	M
PrimateAI	Benign	0.38	T
PROVEAN	Uncertain	-2.4	N
REVEL	Benign	0.083
Sift	Benign	0.037	D
Sift4G	Benign	0.37	T
Polyphen		0.0010	B
Vest4		0.23
MutPred		0.50		Gain of glycosylation at S66 (P = 0.0016);
MVP		0.11
MPC		0.37
ClinPred		0.45	T
GERP RS		-8.4
Varity_R		0.20
gMVP		0.31

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		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: rs958476196; hg19: chr4-88727279;