Variant rs33918778 details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000518.5(HBB):c.123G>T(p.Arg41Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,142 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 Uncertain significance (★★).

Frequency

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

Consequence

HBB
NM_000518.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 1.96

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.968

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HBB	NM_000518.5 linkuse as main transcript	c.123G>T	p.Arg41Ser	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 linkuse as main transcript	c.123G>T	p.Arg41Ser	missense_variant	2/3	1	NM_000518.5	ENSP00000333994	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152142

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152142

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74320

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Feb 09, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Nov 20, 2023	The Hb Austin variant (HBB: c.123G>T; p.Arg41Ser, also known as Arg40Ser when numbered from the mature protein, rs33918778, HbVar ID: 311) is reported in the literature in the heterozygous state in multiple individuals of Mexican ancestry with no clinical symptoms (HbVar and references therein, Racsa 2014, Moo-Penn 1977). However, the phenotype of this variant in the presence of other alpha globin variants is unknown. Functional characterization indicate that the variant hemoglobin has normal Bohr effect, increased oxygen affinity, reduced cooperativity, and found to dissociate into oxyHb dimers (HbVar and references therein). The c.123G>T variant is reported in ClinVar (Variation ID: 439134). It is absent from the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. Computational analyses predict that this variant is deleterious (REVEL: 0.9). Due to the limited information regarding this variant, its clinical significance is uncertain at this time. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/menu.html Racsa LD et al. Beta-Globin gene sequencing of hemoglobin Austin revises the historically reported electrophoretic migration pattern. Arch Pathol Lab Med. 2014 Jun;138(6):819-22. PMID: 24878022. Moo-Penn WF et al. Hemoglobins Austin and Waco: two hemoglobins with substitutions in the alpha 1 beta 2 contact region. Arch Biochem Biophys. 1977 Feb;179(1):86-94. doi: 10.1016/0003-9861(77)90089-3. PMID: 14597. -

beta Thalassemia

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Sep 16, 2020

- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Dec 28, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.47

BayesDel_noAF

Pathogenic

0.44

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.061

T;T;.;T

Eigen

Pathogenic

0.71

Eigen_PC

Pathogenic

0.67

FATHMM_MKL

Uncertain

0.85

LIST_S2

Uncertain

0.95

.;D;D;D

M_CAP

Pathogenic

0.59

MetaRNN

Pathogenic

0.97

D;D;D;D

MetaSVM

Pathogenic

0.97

MutationAssessor

Pathogenic

3.4

M;M;.;.

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.66

PROVEAN

Pathogenic

-5.0

D;.;.;D

REVEL

Pathogenic

0.90

Sift

Pathogenic

0.0

D;.;.;D

Sift4G

Uncertain

0.033

D;.;.;.

Polyphen

1.0

D;D;.;.

Vest4

0.89

MutPred

0.85

Gain of disorder (P = 0.0898);Gain of disorder (P = 0.0898);Gain of disorder (P = 0.0898);Gain of disorder (P = 0.0898);

MVP

0.97

MPC

0.27

ClinPred

0.99

GERP RS

5.1

Varity_R

0.96

gMVP

0.78

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

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