rs35117167

Positions:

• chr11-5225605-T-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The ENST00000335295.4(HBB):​c.437A>G​(p.Tyr146Cys) variant causes a missense change involving the alteration of a 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y146H) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: HBB ENST00000335295.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 7.21

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 9 uncertain in ENST00000335295.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-5225606-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 15112.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978
• PP5: Variant 11-5225605-T-C is Pathogenic according to our data. Variant chr11-5225605-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 15322.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HBB	NM_000518.5	c.437A>G	p.Tyr146Cys	missense_variant	3/3	ENST00000335295.4	NP_000509.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4	c.437A>G	p.Tyr146Cys	missense_variant	3/3	1	NM_000518.5	ENSP00000333994	P1
HBB	ENST00000647020.1	c.437A>G	p.Tyr146Cys	missense_variant	3/3			ENSP00000494175	P1
HBB	ENST00000633227.1	c.*253A>G		3_prime_UTR_variant, NMD_transcript_variant	3/3	3		ENSP00000488004
HBB	ENST00000475226.1			downstream_gene_variant		2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Alfa AF: 0.00152 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Apr 21, 2020	The Hb Rainier variant (HBB: c.437A>G; p.Tyr146Cys, also known as Tyr145Cys when numbered from the mature protein, rs35117167) is reported in the literature in the heterozygous state in multiple individuals affected with erythrocytosis (see link to HbVar and references therein, Adamson 1969). This variant is reported in ClinVar (Variation ID: 15322), and is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. The tyrosine at codon 146 is highly conserved, and functional analyses of the variant protein show increased oxygen affinity (see link to HbVar, Adamson 1969). Additionally, other amino acid substitutions at this codon (Hb Nancy, Hb Osler, Hb Bethesda, Hb McKees Rocks) have been reported in individuals with erythrocytosis and are considered pathogenic (HbVar IDs: 570, 572, 573, 574), and several hemoglobin variants with high oxygen affinity leading to erythrocytosis are located at the carboxy-terminal end of the HBB gene (Wajcman 2004). Based on available information, the Hb Rainier variant is considered to be pathogenic. References: Link to HbVar for Hb Rainier: http://globin.bx.psu.edu/cgi-bin/hbvar/query_vars3?mode=output&display_format=page&i=571 Adamson JW et al. Erythrocytosis associated with hemoglobin Rainier: oxygen equilibria and marrow regulation. J Clin Invest. 1969 Aug;48(8):1376-86. Wajcman H and Galacteros F. Hemoglobins with high oxygen affinity leading to erythrocytosis. New variants and new concepts. Hemoglobin. 2005;29(2):91-106. -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 11, 2019	Not found in the total gnomAD dataset, and the data is high quality. Conflicting predictions of the effect on the protein. Other pathogenic or likely pathogenic variants affect the same amino acid. Assessment of experimental evidence suggests this variant results in abnormal protein function. Very strong co-segregation with disease, and data include affected and unaffected individuals from multiple families. -

Erythrocytosis, familial, 6 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

May 01, 1999

- -

HEMOGLOBIN RAINIER 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	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.36	T;T
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	.;D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.2	H;H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.9	D;.
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;.
Sift4G	Pathogenic	0.0010	D;.
Polyphen		1.0	D;D
Vest4		0.89
MutPred		0.85		Loss of ubiquitination at K145 (P = 0.0343);Loss of ubiquitination at K145 (P = 0.0343);
MVP		0.95
MPC		0.28
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.81
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs35117167; hg19: chr11-5246835;