chr11-5227050-C-T

Variant names:

• chr11-5227050-C-T
• rs34704828
• NM_000518.5:c.-29G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 8P and 1B. PP5_Very_Strong BP4

The NM_000518.5(HBB):​c.-29G>A variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000421 in 1,424,214 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 Pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000039 (0 hom.)
• Consequence: HBB NM_000518.5 5_prime_UTR_premature_start_codon_gain
• Scores: Splicing: ADA: 0.4799
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5 O:1
• Conservation: PhyloP100: 0.536
• Publications: 47 publications found

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

ENSG00000298932 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PP5: Variant 11-5227050-C-T is Pathogenic according to our data. Variant chr11-5227050-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 393702.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5	c.-29G>A		5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 3	ENST00000335295.4	NP_000509.1
HBB	NM_000518.5	c.-29G>A		5_prime_UTR_variant	Exon 1 of 3	ENST00000335295.4	NP_000509.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HBB	ENST00000335295.4	c.-29G>A		5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 3	1	NM_000518.5	ENSP00000333994.3
HBB	ENST00000335295.4	c.-29G>A		5_prime_UTR_variant	Exon 1 of 3	1	NM_000518.5	ENSP00000333994.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152212 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250668 AF XY: 0.00000738

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: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000393 AC: 5 AN: 1272002 Hom.: 0 Cov.: 19 AF XY: 0.00000311 AC XY: 2 AN XY: 642810

African (AFR) AF: 0.00 AC: 0 AN: 29504

American (AMR) AF: 0.00 AC: 0 AN: 44534

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24918

East Asian (EAS) AF: 0.00 AC: 0 AN: 38996

South Asian (SAS) AF: 0.00 AC: 0 AN: 83108

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53332

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5410

European-Non Finnish (NFE) AF: 0.00000426 AC: 4 AN: 937938

Other (OTH) AF: 0.0000184 AC: 1 AN: 54262

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152212 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74352

African (AFR) AF: 0.00 AC: 0 AN: 41450

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68046

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Dec 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 393702). This variant occurs in a non-coding region of the HBB gene. It does not change the encoded amino acid sequence of the HBB protein. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with autosomal recessive beta thalassemia (PMID: 1536956, 1717406, 14734204). This variant is also known as +22 G>A 3' to the Cap site. Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects HBB function (PMID: 10840054, 31395865). For these reasons, this variant has been classified as Pathogenic. -

Mar 03, 2022

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The HBB c.-29G>A variant, (also known as 5’UTR +22 (G->A), rs34704828, HbVar ID: 772) is a pathogenic variant associated with beta+ thalassemia (see HbVar database and references within, Cai 1992, Najmabadi 2002). Expression analyses found that this variant decreases transcription by half (Lewis 2000). This variant is reported in ClinVar (Variation ID: 393702) and is only observed on one allele in the Genome Aggregation Database, indicating it is not a common polymorphism. Based on available information, this variant is considered to be pathogenic. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/hbvar.html Cai SP et al. Two novel beta-thalassemia mutations in the 5' and 3' noncoding regions of the beta-globin gene. Blood. 1992 Mar 1;79(5):1342-6. PMID: 1536956. Lewis BA et al. A downstream element in the human beta-globin promoter: evidence of extended sequence-specific transcription factor IID contacts. Proc Natl Acad Sci USA. 2000 Jun 20;97(13):7172-7. PMID: 10840054. Najmabadi H et al. Rare and unexpected mutations among Iranian beta-thalassemia patients and prenatal samples discovered by reverse-hybridization and DNA sequencing. Haematologica. 2002 Oct;87(10):1113-4. PMID: 12368169. -

Mar 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

HBB: PM3:Very Strong, PM2 -

beta Thalassemia Pathogenic:1 Other:1

May 01, 2025

Molecular Genetics Laboratory, BC Children's and BC Women's Hospitals

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Hemoglobinopathy Pathogenic:1

May 30, 2018

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.-29G>A is located in the untranslated mRNA region 29 nucleotides upstream of the initiation codon. The variant was absent in 245460 control chromosomes. c.-29G>A has been reported in the literature in multiple individuals affected with Beta Thalassemia, including homozygous and compound heterozygous individuals with Beta Thalassemia major and intermedia. These data indicate that the variant is very likely to be associated with disease. One publication reports in vitro evidence suggesting that the variant mildly reduces transcription (58% of normal transcription) and is consistent with a mild Beta Thalassemia phenotype (Lewis_2000). One reputable database has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	18
DANN	Benign	0.90
PhyloP100		0.54
PromoterAI		-0.015	Neutral
Mutation Taster		=31/269	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.48
dbscSNV1_RF	Benign	0.57
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

Other links and lift over

dbSNP: rs34704828; hg19: chr11-5248280;