chr11-5324245-A-G

Position:

• chr11-5324245-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_033180.5(OR51B2):​c.53T>C​(p.Leu18Pro) 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 pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: OR51B2 NM_033180.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.25

Genes affected

OR51B2 (HGNC:14703): (olfactory receptor family 51 subfamily B member 2) Olfactory receptors interact with odorant molecules in the nose, to initiate a neuronal response that triggers the perception of a smell. The olfactory receptor proteins are members of a large family of G-protein-coupled receptors (GPCR) arising from single coding-exon genes. Olfactory receptors share a 7-transmembrane domain structure with many neurotransmitter and hormone receptors and are responsible for the recognition and G protein-mediated transduction of odorant signals. The olfactory receptor gene family is the largest in the genome. The nomenclature assigned to the olfactory receptor genes and proteins for this organism is independent of other organisms. This olfactory receptor gene is a segregating pseudogene, where some individuals have an allele that encodes a functional olfactory receptor, while other individuals have an allele encoding a protein that is predicted to be non-functional. [provided by RefSeq, Jun 2015]

HBE1 (HGNC:4830): (hemoglobin subunit epsilon 1) The epsilon globin gene (HBE) is normally expressed in the embryonic yolk sac: two epsilon chains together with two zeta chains (an alpha-like globin) constitute the embryonic hemoglobin Hb Gower I; two epsilon chains together with two alpha chains form the embryonic Hb Gower II. Both of these embryonic hemoglobins are normally supplanted by fetal, and later, adult hemoglobin. The five beta-like globin genes are found within a 45 kb cluster on chromosome 11 in the following order: 5'-epsilon - G-gamma - A-gamma - delta - beta-3' [provided by RefSeq, Jul 2008]

ENSG00000239920 (HGNC:):

HBG2 (HGNC:4832): (hemoglobin subunit gamma 2) The gamma globin genes (HBG1 and HBG2) are normally expressed in the fetal liver, spleen and bone marrow. Two gamma chains together with two alpha chains constitute fetal hemoglobin (HbF) which is normally replaced by adult hemoglobin (HbA) at birth. In some beta-thalassemias and related conditions, gamma chain production continues into adulthood. The two types of gamma chains differ at residue 136 where glycine is found in the G-gamma product (HBG2) and alanine is found in the A-gamma product (HBG1). The former is predominant at birth. The order of the genes in the beta-globin cluster is: 5'- epsilon -- gamma-G -- gamma-A -- delta -- beta--3'. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.746

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
OR51B2	NM_033180.5	c.53T>C	p.Leu18Pro	missense_variant	1/1	ENST00000624187.1	NP_149420.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
OR51B2	ENST00000624187.1	c.53T>C	p.Leu18Pro	missense_variant	1/1	6	NM_033180.5	ENSP00000485407.1
ENSG00000239920	ENST00000380259.7	n.*866+21528T>C		intron_variant		5		ENSP00000369609.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 65

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000189

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

Nov 15, 2023

The c.53T>C (p.L18P) alteration is located in exon 1 (coding exon 1) of the OR51B2 gene. This alteration results from a T to C substitution at nucleotide position 53, causing the leucine (L) at amino acid position 18 to be replaced by a proline (P). 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	0.29
BayesDel_addAF	Benign	-0.095	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	20
DANN	Uncertain	1.0
DEOGEN2	Benign	0.030	T
Eigen	Uncertain	0.21
Eigen_PC	Benign	0.0071
FATHMM_MKL	Benign	0.57	D
LIST_S2	Benign	0.58	T
M_CAP	Benign	0.0083	T
MetaRNN	Pathogenic	0.75	D
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.9	L
MutationTaster	Benign	0.98	D;D;D;N
PrimateAI	Benign	0.41	T
Polyphen		0.99	D
MutPred		0.66		Gain of disorder (P = 0.0093);
ClinPred		0.83	D
GERP RS		4.4
Varity_R		0.23
gMVP		0.24

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1835436741; hg19: chr11-5345475;