11-5225719-C-T

Variant names:

• chr11-5225719-C-T
• rs35519485
• NM_000518.5:c.323G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_000518.5(HBB):​c.323G>A​(p.Gly108Asp) 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G108R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: HBB NM_000518.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.33

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• PP5: Variant 11-5225719-C-T is Pathogenic according to our data. Variant chr11-5225719-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2735520.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5	c.323G>A	p.Gly108Asp	missense_variant	Exon 3 of 3	ENST00000335295.4	NP_000509.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4	c.323G>A	p.Gly108Asp	missense_variant	Exon 3 of 3	1	NM_000518.5	ENSP00000333994.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Jun 16, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 108 of the HBB protein (p.Gly108Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with beta-thalassemia intermedia (PMID: 7668221, 16987796). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is also known as Hb Lulu Island or beta107(G9)Gly -> Asp. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on HBB protein function. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.18	T;T
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	0.98	.;D
M_CAP	Pathogenic	0.56	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.1	H;H
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-5.7	D;.
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;.
Sift4G	Uncertain	0.0020	D;.
Polyphen		1.0	D;D
Vest4		0.91
MutPred		0.92		Loss of methylation at R105 (P = 0.1885);Loss of methylation at R105 (P = 0.1885);
MVP		0.96
MPC		0.28
ClinPred		0.99	D
GERP RS		3.8
Varity_R		0.95
gMVP		0.93

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: rs35519485; hg19: chr11-5246949;