16-173500-T-C

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1PM2PM5PP3_Strong

The NM_000517.6(HBA2):​c.329T>C​(p.Leu110Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000125 in 1,606,358 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L110R) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000068 ( 0 hom., cov: 25)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

HBA2
NM_000517.6 missense

Scores

8
6
2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 5.55

Publications

1 publications found
Variant links:
Genes affected
HBA2 (HGNC:4824): (hemoglobin subunit alpha 2) The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (HBA2) and alpha-1 (HBA1) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions. Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with HbF (fetal hemoglobin) makes up the remaining 3% of adult hemoglobin. Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some nondeletion alpha thalassemias have also been reported. [provided by RefSeq, Jul 2008]
HBA2 Gene-Disease associations (from GenCC):
  • alpha thalassemia spectrum
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
  • erythrocytosis, familial, 7
    Inheritance: AD Classification: STRONG, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • hemoglobin M disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Hb Bart's hydrops fetalis
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hemoglobin H disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Heinz body anemia
    Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
  • methemoglobinemia, alpha type
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 12 uncertain in NM_000517.6
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-173500-T-G is described in ClinVar as Pathogenic|other. ClinVar VariationId is 15632.Status of the report is no_assertion_criteria_provided, 0 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.968

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBA2NM_000517.6 linkc.329T>C p.Leu110Pro missense_variant Exon 3 of 3 ENST00000251595.11 NP_000508.1 P69905D1MGQ2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBA2ENST00000251595.11 linkc.329T>C p.Leu110Pro missense_variant Exon 3 of 3 1 NM_000517.6 ENSP00000251595.6 P69905

Frequencies

GnomAD3 genomes
AF:
0.00000676
AC:
1
AN:
147874
Hom.:
0
Cov.:
25
show subpopulations
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000485
GnomAD4 exome
AF:
6.86e-7
AC:
1
AN:
1458484
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
725352
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31720
American (AMR)
AF:
0.00
AC:
0
AN:
44676
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26096
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85200
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53294
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5714
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111884
Other (OTH)
AF:
0.00
AC:
0
AN:
60216
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000676
AC:
1
AN:
147874
Hom.:
0
Cov.:
25
AF XY:
0.0000139
AC XY:
1
AN XY:
72190
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
37560
American (AMR)
AF:
0.00
AC:
0
AN:
15148
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5166
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4642
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67978
Other (OTH)
AF:
0.000485
AC:
1
AN:
2060
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.54
D
BayesDel_noAF
Pathogenic
0.53
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.38
.;T
Eigen
Uncertain
0.62
Eigen_PC
Uncertain
0.46
FATHMM_MKL
Uncertain
0.86
D
M_CAP
Pathogenic
0.94
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
1.1
D
PhyloP100
5.6
PrimateAI
Uncertain
0.57
T
PROVEAN
Pathogenic
-5.8
D;D
REVEL
Pathogenic
0.88
Sift
Pathogenic
0.0
D;D
Sift4G
Uncertain
0.015
D;D
Vest4
0.65
MutPred
0.84
Loss of stability (P = 0.0152);.;
MVP
1.0
MPC
3.2
ClinPred
0.99
D
GERP RS
4.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.3
gMVP
0.98
Mutation Taster
=18/82
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

Publications

Other links and lift over

dbSNP: rs41479844; hg19: chr16-223499; API