11-5226662-G-T

Variant names:

• chr11-5226662-G-T
• rs33985847
• NM_000518.5:c.230C>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_000518.5(HBB):​c.230C>A​(p.Ala77Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,874 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 other (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A77P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: HBB NM_000518.5 missense
• Clinical Significance: other no assertion criteria provided O:1
• Conservation: PhyloP100: 2.44
• Publications: 3 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: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
• erythrocytosis, familial, 6

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen
• hemoglobin M disease

  Inheritance: AD Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, ClinGen, Orphanet
• unstable hemoglobin disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: 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), Ambry Genetics, ClinGen
• sickle cell disease and related diseases

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Heinz body anemia

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• sickle cell disease

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• 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 3 ACMG points.

• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 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=0.32723993).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000518.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HBB	NM_000518.5	MANE Select	c.230C>A	p.Ala77Asp	missense	Exon 2 of 3	NP_000509.1	D9YZU5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HBB	ENST00000335295.4	TSL:1 MANE Select	c.230C>A	p.Ala77Asp	missense	Exon 2 of 3	ENSP00000333994.3	P68871
	HBB	ENST00000485743.1	TSL:1	c.230C>A	p.Ala77Asp	missense	Exon 2 of 2	ENSP00000496200.1	A0A2R8Y7R2
	HBB	ENST00000647020.1		c.230C>A	p.Ala77Asp	missense	Exon 2 of 3	ENSP00000494175.1	P68871

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461874 Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0 AN XY: 727242

⚠️ 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: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: other

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
-	-	-	HEMOGLOBIN J (CHICAGO) (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.24
CADD	Benign	16
DANN	Benign	0.74
DEOGEN2	Benign	0.021	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.084	N
LIST_S2	Benign	0.80	T
M_CAP	Uncertain	0.19	D
MetaRNN	Benign	0.33	T
MetaSVM	Uncertain	-0.19	T
MutationAssessor	Benign	0.27	N
PhyloP100		2.4
PrimateAI	Benign	0.39	T
PROVEAN	Benign	0.17	N
REVEL	Uncertain	0.58
Sift	Uncertain	0.0070	D
Sift4G	Benign	0.062	T
Polyphen		0.010	B
Vest4		0.64
MutPred		0.48		Gain of disorder (P = 0.0655)
MVP		0.50
MPC		0.053
ClinPred		0.21	T
GERP RS		1.5
PromoterAI		0.00020	Neutral
Varity_R		0.24
gMVP		0.70
Mutation Taster		=19/81	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: rs33985847; hg19: chr11-5247892;