11-5226961-C-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1PM2PP3PP5_Very_Strong

The NM_000518.5(HBB):c.61G>A(p.Val21Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,802 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V21E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

HBB
NM_000518.5 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: -0.0690

Variant links:

Genes affected

HBB (HGNC:4827): (hemoglobin subunit beta) The alpha (HBA) and beta (HBB) loci determine the structure of the 2 types of polypeptide chains in adult hemoglobin, Hb A. The normal adult hemoglobin tetramer consists of two alpha chains and two beta chains. Mutant beta globin causes sickle cell anemia. Absence of beta chain causes beta-zero-thalassemia. Reduced amounts of detectable beta globin causes beta-plus-thalassemia. 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]

HBB links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 13 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 16 uncertain in NM_000518.5

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.84

PP5

Variant 11-5226961-C-T is Pathogenic according to our data. Variant chr11-5226961-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 15300.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HBB	NM_000518.5 linkuse as main transcript	c.61G>A	p.Val21Met	missense_variant	1/3	ENST00000335295.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HBB	ENST00000335295.4 linkuse as main transcript	c.61G>A	p.Val21Met	missense_variant	1/3	1	NM_000518.5	P1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.00000398

AC:

AN:

251260

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135780

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000411

AC:

AN:

1461602

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727128

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000447

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

AF:

0.0000131

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74372

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

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

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Jun 22, 2018	The HBB c.61G>A (p.Val21Met) variant, also known as Hb Olympia has been reported in individuals presenting with erythrocytosis (PMIDs: 35052427 (2022), 23859443 (2013), and 2599884 (1989)). In addition, this variant has been reported to have increased oxygen affinity and is mildly unstable (PMIDs: 31553106 (2020) and 2599884 (1989)). Based on the available information, this variant is classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Mar 04, 2020	The Hb Olympia variant (HBB: c.61G>A; p.Val21Met, also known as Val20Met when numbered from the mature protein, rs35890959) is reported in the literature in multiple individuals affected with erythrocytosis (Bento 2013, Gonzalez Fernandez 2009, Percy 2009, Stamatoyannopoulos 1973, Wajcman 2005, HbVar database and references therein). This variant has been observed to segregate with erythrocytosis in a family in a pattern consistent with autosomal dominant inheritance (Stamatoyannopoulos 1973). Further, while heterozygous individuals with this variant are reported with mild erythrocytosis, those carrying both Hb Olympia and a beta-thalassemia allele are reported to exhibit more severe symptoms (Wajcman 2005). The Hb Olympia variant is found on a single chromosome in the Genome Aggregation Database (1/251260 alleles), indicating it is not a common polymorphism. The valine at codon 21 is highly conserved, and functional studies indicate increased oxygen affinity of the variant protein (Stamatoyannopoulos 1973). Based on available information, this variant is considered to be pathogenic. References: HbVar link to Hb Olympia: http://globin.bx.psu.edu/cgi-bin/hbvar/query_vars3?mode=output&display_format=page&i=257 Bento C et al. Molecular study of congenital erythrocytosis in 70 unrelated patients revealed a potential causal mutation in less than half of the cases (Where is/are the missing gene(s)?). Eur J Haematol. 2013 Oct;91(4):361-8. Gonzalez Fernandez FA et al. Haemoglobinopathies with high oxygen affinity. Experience of Erythropathology Cooperative Spanish Group. Ann Hematol. 2009 Mar;88(3):235-8. Percy MJ et al. Identification of high oxygen affinity hemoglobin variants in the investigation of patients with erythrocytosis. Haematologica. 2009 Sep;94(9):1321-2. Stamatoyannopoulos G et al. Hemoglobin olympia ( 20 valine leads to methionine): an electrophoretically silent variant associated with high oxygen affinity and erythrocytosis. J Clin Invest. 1973 Feb;52(2):342-9. Wajcman H and Galacteros F. Hemoglobins with high oxygen affinity leading to erythrocytosis. New variants and new concepts. Hemoglobin. 2005;29(2):91-106. -

Erythrocytosis, familial, 6

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 1987

- -

alpha Thalassemia;C0002895:Hb SS disease;C0019025:Hereditary persistence of fetal hemoglobin;C0700299:Heinz body anemia;C1840779:Methemoglobinemia, beta-globin type;C1858990:Dominant beta-thalassemia;C1970028:Malaria, susceptibility to;C4693822:Erythrocytosis, familial, 6;CN322236:Beta-thalassemia HBB/LCRB

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 11, 2022

- -

HEMOGLOBIN OLYMPIA

Other:1

other, no assertion criteria provided

literature only

OMIM

Dec 12, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.26

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.17

Cadd

Benign

Dann

Uncertain

1.0

DEOGEN2

Benign

0.037

T;T;.;T

Eigen

Benign

-0.22

Eigen_PC

Benign

-0.39

FATHMM_MKL

Benign

0.27

M_CAP

Uncertain

0.26

MetaRNN

Pathogenic

0.84

D;D;D;D

MetaSVM

Uncertain

-0.15

MutationAssessor

Pathogenic

3.5

M;M;.;.

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-1.9

N;.;.;N

REVEL

Uncertain

0.57

Sift

Uncertain

0.015

D;.;.;D

Sift4G

Benign

0.10

T;.;.;.

Polyphen

0.94

P;P;.;.

Vest4

0.51

MutPred

0.69

Gain of loop (P = 0.1069);Gain of loop (P = 0.1069);Gain of loop (P = 0.1069);Gain of loop (P = 0.1069);

MVP

0.80

MPC

0.053

ClinPred

0.60

GERP RS

3.3

Varity_R

0.33

gMVP

0.72

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.070

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over