rs33918131

Variant names:

• chr11-5226993-G-C
• rs33918131
• NM_000518.5:c.29C>G

Your query was ambiguous. Multiple possible variants found:

• chr11-5226993-G-C
• chr11-5226993-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4 BP6

The NM_000518.5(HBB):​c.29C>G​(p.Ser10Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,866 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S10Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: HBB NM_000518.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2 O:1
• Conservation: PhyloP100: -1.31
• Publications: 10 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: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 10 benign, 37 uncertain in NM_000518.5
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.29318225).
• BP6: Variant 11-5226993-G-C is Benign according to our data. Variant chr11-5226993-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 15316.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HBB	NM_000518.5	c.29C>G	p.Ser10Cys	missense_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.29C>G	p.Ser10Cys	missense_variant	Exon 1 of 3	1	NM_000518.5	ENSP00000333994.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251216 AF XY: 0.00000737

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460866 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726838

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33444

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111110

Other (OTH) AF: 0.0000166 AC: 1 AN: 60358

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1 Benign:1

Jan 17, 2017

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 24, 2021

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.29C>G (p.Ser10Cys) results in a non-conservative amino acid change located in the Globin domain (IPR000971) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251216 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.29C>G has been reported in the literature in individuals affected with Hemoglobinopathy (e.g. Goncalves_1994). However, this variant was also found in patients in heterozygous or homozygous state, who have normal hematological values (e.g. Colombo_1985, Malcorra-Azpiazu_1993, Cataldo_2012). These data do not allow any conclusion about variant significance. At least one publication reports experimental evidence evaluating an impact on protein function. These results showed no damaging effect of this variant (Tondo_1974). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

not provided Benign:1

Oct 04, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

HEMOGLOBIN PORTO ALEGRE Other:1

May 09, 2000

OMIM

Significance: other

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.14
CADD	Benign	1.6
DANN	Benign	0.78
DEOGEN2	Benign	0.036	T;T;.;T
Eigen	Benign	-2.0
Eigen_PC	Benign	-2.1
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.45	.;T;T;T
M_CAP	Pathogenic	0.32	D
MetaRNN	Benign	0.29	T;T;T;T
MetaSVM	Benign	-0.46	T
MutationAssessor	Uncertain	2.3	M;M;.;.
PhyloP100		-1.3
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-1.9	N;.;.;N
REVEL	Uncertain	0.53
Sift	Uncertain	0.013	D;.;.;D
Sift4G	Uncertain	0.018	D;.;.;.
Polyphen		0.0010	B;B;.;.
Vest4		0.83
MutPred		0.39		Loss of disorder (P = 9e-04);Loss of disorder (P = 9e-04);Loss of disorder (P = 9e-04);Loss of disorder (P = 9e-04);
MVP		0.56
MPC		0.18
ClinPred		0.93	D
GERP RS		-7.0
PromoterAI		-0.046	Neutral
Varity_R		0.30
gMVP		0.59
Mutation Taster		=3/97	disease causing

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

Other links and lift over

dbSNP: rs33918131; hg19: chr11-5248223;