rs748782183

chr17-48726842-C-Gchr17-48726842-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_006361.6(HOXB13):c.803G>C(p.Arg268Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R268G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: HOXB13 NM_006361.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.91

Genes affected

HOXB13 (HGNC:5112): (homeobox B13) This gene encodes a transcription factor that belongs to the homeobox gene family. Genes of this family are highly conserved among vertebrates and essential for vertebrate embryonic development. This gene has been implicated to play a role in fetal skin development and cutaneous regeneration. In mice, a similar gene was shown to exhibit temporal and spatial colinearity in the main body axis of the embryo, but was not expressed in the secondary axes, which suggests functions in body patterning along the axis. This gene and other HOXB genes form a gene cluster at chromosome the 17q21-22 region. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HOXB13	NM_006361.6	c.803G>C	p.Arg268Pro	missense_variant	2/2	ENST00000290295.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HOXB13	ENST00000290295.8	c.803G>C	p.Arg268Pro	missense_variant	2/2	1	NM_006361.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 20, 2022

ClinVar contains an entry for this variant (Variation ID: 1001068). This variant has not been reported in the literature in individuals affected with HOXB13-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 268 of the HOXB13 protein (p.Arg268Pro). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 28, 2024

The p.R268P variant (also known as c.803G>C), located in coding exon 2 of the HOXB13 gene, results from a G to C substitution at nucleotide position 803. The arginine at codon 268 is replaced by proline, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	33
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.51	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.6	H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-5.5	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.010	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.90		Loss of stability (P = 0.0443);
MVP		0.97
MPC		1.5
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.99
gMVP		0.95

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: rs748782183; hg19: chr17-46804204;