11-5225635-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP4

The NM_000518.5(HBB):c.407C>T(p.Ala136Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,742 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 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. A136D) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

HBB
NM_000518.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.18

Publications

4 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 1 ACMG points.

PM1

In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 40 uncertain in NM_000518.5

BP4

Computational evidence support a benign effect (MetaRNN=0.37200397).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5 link	c.407C>T	p.Ala136Val	missense_variant	Exon 3 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.407C>T	p.Ala136Val	missense_variant	Exon 3 of 3	1	NM_000518.5	ENSP00000333994.3		P68871

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251362

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461742

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727204

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000812

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111876

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.489

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

Cov.:

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Nov 01, 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.407C>T (p.Ala136Val) results in a non-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 1.6e-05 in 251362 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.407C>T has been reported in the literature in at least one compound heterozygous individual affected with Hemoglobinopathy (e.g., Godbole_2018). These data do not allow any conclusion about variant significance. At least one publication reports experimental evidence evaluating an impact on protein function, finding that the variant results in a mildly decreased oxygen affinity (e.g., Zubriggen_2009). The following publications have been ascertained in the context of this evaluation (PMID: 29651865, 29365076, 19958196). No submitters have reported clinical-significance assessments for this variant to ClinVar after 2014. Additionally, other missense variants have been reported in the literature in individuals affected with hemolytic anemia (c.406G>C (p.Ala136Pro) also known as Hb Altdorf) or silent hemoglobinopathies (c.407C>A (p.Ala136Asp), also known as Hb Beckman), and these other missense variants were found to be unstable and result in changes in oxygen affinity (PMIDs: 8450301, 1261680, 19453576, 26209877; Yucel_2013, no PMID)). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.37

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.037

T;T

Eigen

Benign

-0.15

Eigen_PC

Benign

-0.13

FATHMM_MKL

Benign

0.65

LIST_S2

Benign

0.72

.;T

M_CAP

Uncertain

0.21

MetaRNN

Benign

0.37

T;T

MetaSVM

Uncertain

0.63

MutationAssessor

Pathogenic

3.4

M;M

PhyloP100

2.2

PrimateAI

Benign

0.34

PROVEAN

Benign

-1.7

N;.

REVEL

Uncertain

0.56

Sift

Uncertain

0.012

D;.

Sift4G

Uncertain

0.057

T;.

Polyphen

0.090

B;B

Vest4

0.40

MutPred

0.38

Loss of disorder (P = 0.1535);Loss of disorder (P = 0.1535);

MVP

0.75

MPC

0.034

ClinPred

0.77

GERP RS

3.8

Varity_R

0.23

gMVP

0.81

Mutation Taster

=6/94

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