16-173500-T-C

Variant names:

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

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: ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
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
unstable hemoglobin disease
Inheritance: AD Classification: LIMITED Submitted by: ClinGen

HBA2 links:

ENSG00000294455 (HGNC:):

ENSG00000294455 links:

Genome browser will be placed here

new If you want to explore the variant's impact on the transcript NM_000517.6, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

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, 14 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000517.6. 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
	HBA2	NM_000517.6	MANE Select	c.329T>C	p.Leu110Pro	missense	Exon 3 of 3	NP_000508.1	D1MGQ2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
HBA2	ENST00000251595.11	TSL:1 MANE Select	c.329T>C	p.Leu110Pro	missense	Exon 3 of 3	ENSP00000251595.6	P69905
HBA2	ENST00000482565.1	TSL:1	n.465T>C		non_coding_transcript_exon	Exon 2 of 2
HBA2	ENST00000397806.1	TSL:2	c.233T>C	p.Leu78Pro	missense	Exon 3 of 3	ENSP00000380908.1	G3V1N2

Frequencies

GnomAD3 genomes

AF:

0.00000676

AC:

AN:

147874

Hom.:

Cov.:

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:

AN:

1458484

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

725352

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

31720

American (AMR)

AF:

0.00

AC:

AN:

44676

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26096

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.00

AC:

AN:

85200

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53294

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5714

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111884

Other (OTH)

AF:

0.00

AC:

AN:

60216

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

AN:

147874

Hom.:

Cov.:

AF XY:

0.0000139

AC XY:

AN XY:

72190

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

37560

American (AMR)

AF:

0.00

AC:

AN:

15148

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5166

South Asian (SAS)

AF:

0.00

AC:

AN:

4642

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67978

Other (OTH)

AF:

0.000485

AC:

AN:

2060

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.54

BayesDel_noAF

Pathogenic

0.53

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.38

Eigen

Uncertain

0.62

Eigen_PC

Uncertain

0.46

FATHMM_MKL

Uncertain

0.86

M_CAP

Pathogenic

0.94

MetaRNN

Pathogenic

0.97

MetaSVM

Pathogenic

1.1

PhyloP100

5.6

PrimateAI

Uncertain

0.57

PROVEAN

Pathogenic

-5.8

REVEL

Pathogenic

0.88

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.015

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.3

gMVP

0.98

Mutation Taster

=18/82

disease causing

(source)

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over