chr17-48529689-C-T

Position:

• chr17-48529689-C-T

Variant summary

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

The NM_002144.4(HOXB1):​c.764G>A​(p.Arg255Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,922 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 (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: HOXB1 NM_002144.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.91

Genes affected

HOXB1 (HGNC:5111): (homeobox B1) This gene belongs to the homeobox family of genes. The homeobox genes encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms. Mammals possess four similar homeobox gene clusters, HOXA, HOXB, HOXC and HOXD, located on different chromosomes, consisting of 9 to 11 genes arranged in tandem. This gene is one of several homeobox HOXB genes located in a cluster on chromosome 17. [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, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HOXB1	NM_002144.4	c.764G>A	p.Arg255Gln	missense_variant	2/2	ENST00000239174.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HOXB1	ENST00000239174.7	c.764G>A	p.Arg255Gln	missense_variant	2/2	1	NM_002144.4	P1
HOXB1	ENST00000577092.1	c.*517G>A		3_prime_UTR_variant	1/1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460922 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726690

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Facial paresis, hereditary congenital, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Jun 15, 2018

The homozygous p.Arg255Gln variant was identified by our study in two siblings with Hereditary Congenital Facial Paresis. This variant was absent from large population studies. The Arginine (Arg) at position 255 is highly conserved in mammals and evolutionarily distant species, raising the possibility that a change at this position may not be tolerated. Computational prediction tools suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of this variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	D;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	.;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	5.2	H;H
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Uncertain	-3.5	D;.
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0	D;.
Polyphen		1.0	D;D
Vest4		0.87
MutPred		0.85		Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);
MVP		0.98
MPC		1.4
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.95
gMVP		0.92

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: rs1567932264; hg19: chr17-46607051;