rs281864891

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_000184.3(HBG2):​c.68A>T​(p.Asp23Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict 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. D23G) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 22)

Consequence

HBG2
NM_000184.3 missense

Scores

18

Clinical Significance

other no assertion criteria provided O:1

Conservation

PhyloP100: 1.26

Publications

1 publications found
Variant links:
Genes affected
HBG2 (HGNC:4832): (hemoglobin subunit gamma 2) The gamma globin genes (HBG1 and HBG2) are normally expressed in the fetal liver, spleen and bone marrow. Two gamma chains together with two alpha chains constitute fetal hemoglobin (HbF) which is normally replaced by adult hemoglobin (HbA) at birth. In some beta-thalassemias and related conditions, gamma chain production continues into adulthood. The two types of gamma chains differ at residue 136 where glycine is found in the G-gamma product (HBG2) and alanine is found in the A-gamma product (HBG1). The former is predominant at birth. 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]
HBG2 Gene-Disease associations (from GenCC):
  • hemoglobinopathy Toms River
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • hereditary persistence of fetal hemoglobin-beta-thalassemia syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • hereditary persistence of fetal hemoglobin-sickle cell disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • cyanosis, transient neonatal
    Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 7 uncertain in NM_000184.3
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.114187986).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBG2NM_000184.3 linkc.68A>T p.Asp23Val missense_variant Exon 1 of 3 ENST00000336906.6 NP_000175.1 P69892D9YZU9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBG2ENST00000336906.6 linkc.68A>T p.Asp23Val missense_variant Exon 1 of 3 1 NM_000184.3 ENSP00000338082.4 P69892
ENSG00000284931ENST00000642908.1 linkc.68A>T p.Asp23Val missense_variant Exon 1 of 3 ENSP00000495346.1
ENSG00000239920ENST00000380259.7 linkn.*1371A>T non_coding_transcript_exon_variant Exon 7 of 8 5 ENSP00000369609.3 A0A2U3TZJ3
ENSG00000239920ENST00000380259.7 linkn.*1371A>T 3_prime_UTR_variant Exon 7 of 8 5 ENSP00000369609.3 A0A2U3TZJ3

Frequencies

GnomAD3 genomes
Cov.:
22
GnomAD4 exome
Cov.:
10
GnomAD4 genome
Cov.:
22

ClinVar

Significance: other
Submissions summary: Other:1
Revision: no assertion criteria provided
LINK: link

Submissions by phenotype

HEMOGLOBIN F (GRANADA) Other:1
Aug 18, 2016
OMIM
Significance:other
Review Status:no assertion criteria provided
Collection Method:literature only

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Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.061
BayesDel_addAF
Benign
-0.031
T
BayesDel_noAF
Benign
-0.28
CADD
Benign
15
DANN
Benign
0.92
DEOGEN2
Benign
0.059
.;.;T
Eigen
Benign
-1.0
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.14
N
LIST_S2
Benign
0.77
T;T;T
M_CAP
Benign
0.024
T
MetaRNN
Benign
0.11
T;T;T
MetaSVM
Benign
-0.64
T
MutationAssessor
Benign
0.49
.;.;N
PhyloP100
1.3
PROVEAN
Benign
-2.2
.;.;N
REVEL
Benign
0.27
Sift
Benign
0.046
.;.;D
Sift4G
Benign
0.14
.;.;T
Polyphen
0.0
.;.;B
Vest4
0.14
MutPred
0.61
Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);
MVP
0.60
ClinPred
0.059
T
GERP RS
-2.6
PromoterAI
0.019
Neutral
Varity_R
0.31
gMVP
0.51
Mutation Taster
=26/74
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.10
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs281864891; hg19: chr11-5275891; API