rs868269606

Variant names:

• chr11-5226781-AG-A
• rs267607297
• NM_000518.5:c.110delC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000518.5(HBB):​c.110delC​(p.Pro37LeufsTer25) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: HBB NM_000518.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 6.33

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 116 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-5226781-AG-A is Pathogenic according to our data. Variant chr11-5226781-AG-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 15424.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-5226781-AG-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5	c.110delC	p.Pro37LeufsTer25	frameshift_variant	Exon 2 of 3	ENST00000335295.4	NP_000509.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4	c.110delC	p.Pro37LeufsTer25	frameshift_variant	Exon 2 of 3	1	NM_000518.5	ENSP00000333994.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

beta Thalassemia Pathogenic:3

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 25, 2019

The ITHANET community portal, The Cyprus Institute of Neurology and Genetics

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

- -

Mar 05, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: HBB c.110delC (p.Pro37LeufsX25) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 251358 control chromosomes. c.110delC has been reported in the literature in multiple individuals affected with Beta Thalassemia (example, Yang_1989, Shaji_2003, Rujito_2015). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 15424). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2

Apr 10, 2021

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 02, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The HBB c.110del (p.Pro37Leufs*25) variant alters the translational reading frame of the HBB mRNA and causes the premature termination of HBB protein synthesis. This variant has been reported in the published literature to be associated with beta(0)-thalassemia, including many individuals affected with beta-thalassemia or in heterozygous carriers showing hematological evidence of thalassemia trait, especially in southeast Asian populations (see HbVar (http://globin.cse.psu.edu/cgi-bin/hbvar/counter), PMID: 2736244 (1989), 12709369 (2003), 21077770 (2010), 22335963 (2012), 23682686 (2013), 26291967 (2015), 31890591 (2019), 32638316 (2020)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as pathogenic. -

Beta zero thalassemia Pathogenic:1

May 01, 1989

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

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: rs267607297; hg19: chr11-5248011;