rs36008922

Positions:

• chr11-5226690-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000518.5(HBB):​c.202G>A​(p.Val68Met) variant causes a missense change. 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 other (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Likely benignin UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V68A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HBB NM_000518.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1 O:2
• Conservation: PhyloP100: 3.64

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-5226689-A-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HBB	NM_000518.5	c.202G>A	p.Val68Met	missense_variant	2/3	ENST00000335295.4	NP_000509.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4	c.202G>A	p.Val68Met	missense_variant	2/3	1	NM_000518.5	ENSP00000333994.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:2

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Nov 05, 2024

The HBB c.202G>A (p.Val68Met) variant (also known as Hb Bristol, Hb Alesha, Hb Bristol-Alesha) has been characterized as a unstable hemoglobin variant, reported in the heterozygous state in multiple individuals with transfusion-dependent, severe hemolytic anemia (PMIDs: 37457725 (2023), 35091138 (2022), 17654076 (2007), 15646651 (2004), 8704193 (1996), 8330974 (1993)), and occurred as a de novo variant in two families (PMIDs: 28670945 (2017), 30316205 (2019)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, this variant is classified as pathogenic. -

HEMOGLOBIN ALESHA Other:1

other, no assertion criteria provided

literature only

OMIM

Jun 01, 1993

- -

HEMOGLOBIN BRISTOL 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	0.98
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.21	T;T;.;T
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	.;D;D;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M;M;.;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-2.5	D;.;.;D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D;.;.;D
Sift4G	Uncertain	0.024	D;.;.;.
Polyphen		1.0	D;D;.;.
Vest4		0.70
MutPred		0.94		Gain of disorder (P = 0.0695);Gain of disorder (P = 0.0695);Gain of disorder (P = 0.0695);Gain of disorder (P = 0.0695);
MVP		0.85
MPC		0.17
ClinPred		0.98	D
GERP RS		5.1
Varity_R		0.67
gMVP		0.89

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: rs36008922; hg19: chr11-5247920;