rs33952147

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_000518.5(HBB):c.259G>T(p.Ala87Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A87P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

HBB
NM_000518.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.0670

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

dominant beta-thalassemia
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
hemoglobin M disease
Inheritance: AD Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, ClinGen
beta thalassemia
Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
beta-thalassemia HBB/LCRB
Inheritance: AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
sickle cell disease and related diseases
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
erythrocytosis, familial, 6
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
Heinz body anemia
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
sickle cell disease
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
hereditary persistence of fetal hemoglobin-beta-thalassemia syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
beta-thalassemia intermedia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
beta-thalassemia major
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
delta-beta-thalassemia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hemoglobin C disease
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hemoglobin C-beta-thalassemia syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hemoglobin E disease
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hemoglobin E-beta-thalassemia syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hereditary persistence of fetal hemoglobin-sickle cell disease syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
sickle cell-beta-thalassemia disease syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
sickle cell-hemoglobin c disease syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
sickle cell-hemoglobin d disease syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
sickle cell-hemoglobin E disease syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

HBB links:

ENSG00000298932 (HGNC:):

ENSG00000298932 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1

In a hotspot region, there are 19 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 28 uncertain in NM_000518.5

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5 link	c.259G>T	p.Ala87Ser	missense_variant	Exon 2 of 3	ENST00000335295.4	NP_000509.1	P68871D9YZU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4 link	c.259G>T	p.Ala87Ser	missense_variant	Exon 2 of 3	1	NM_000518.5	ENSP00000333994.3		P68871

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152140

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251424

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1461856

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727236

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000719

AC:

AN:

1111978

Other (OTH)

AF:

0.00

AC:

AN:

60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.275

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Data not reliable, filtered out with message: AS_VQSR

AF:

0.00000657

AC:

AN:

152140

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74306

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41428

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68044

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 28, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: HBB c.259G>T (p.Ala87Ser) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251424 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.259G>T in individuals affected with Beta Thalassemia and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.086

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

-0.050

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.036

T;T;.;T

Eigen

Benign

-0.22

Eigen_PC

Benign

-0.20

FATHMM_MKL

Benign

0.43

LIST_S2

Benign

0.74

.;T;T;T

M_CAP

Pathogenic

0.34

MetaRNN

Uncertain

0.51

D;D;D;D

MetaSVM

Uncertain

0.71

MutationAssessor

Benign

1.3

L;L;.;.

PhyloP100

-0.067

PrimateAI

Benign

0.45

PROVEAN

Benign

-2.1

N;.;.;N

REVEL

Uncertain

0.61

Sift

Benign

0.075

T;.;.;T

Sift4G

Benign

0.36

T;.;.;.

Polyphen

0.0060

B;B;.;.

Vest4

0.58

MutPred

0.57

Gain of disorder (P = 0.0452);Gain of disorder (P = 0.0452);Gain of disorder (P = 0.0452);Gain of disorder (P = 0.0452);

MVP

0.66

MPC

0.058

ClinPred

0.36

GERP RS

4.3

PromoterAI

-0.022

Neutral

(source)

Varity_R

0.37

gMVP

0.72

Mutation Taster

=12/88

disease causing

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over