16-173206-C-A

Position:

• chr16-173206-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_Strong

The NM_000517.6(HBA2):​c.177C>A​(p.His59Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as other (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Likely benignin UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H59Y) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 18)
• Consequence: HBA2 NM_000517.6 missense
• Clinical Significance: other no assertion criteria provided O:1
• Conservation: PhyloP100: -5.13

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HBA2	NM_000517.6	c.177C>A	p.His59Gln	missense_variant	2/3	ENST00000251595.11	NP_000508.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HBA2	ENST00000251595.11	c.177C>A	p.His59Gln	missense_variant	2/3	1	NM_000517.6	ENSP00000251595	P1
HBA2	ENST00000484216.1	c.147C>A	p.His49Gln	missense_variant	2/2	1		ENSP00000495899
HBA2	ENST00000482565.1	n.313C>A		non_coding_transcript_exon_variant	1/2	1
HBA2	ENST00000397806.1	c.81C>A	p.His27Gln	missense_variant	2/3	2		ENSP00000380908

Frequencies

GnomAD3 genomes Cov.: 18

GnomAD4 exome Cov.: 14

GnomAD4 genome Cov.: 18

ClinVar

Significance: other

Submissions summary: Other:1

Revision: no assertion criteria provided

Submissions by phenotype

HEMOGLOBIN BOGHE Other:1

other, no assertion criteria provided

literature only

OMIM

Oct 13, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
CADD	Benign	6.8
DANN	Benign	0.84
DEOGEN2	Benign	0.11	.;T
Eigen	Benign	-0.67
Eigen_PC	Benign	-0.98
FATHMM_MKL	Benign	0.036	N
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Uncertain	0.39	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-7.0	D;D
REVEL	Uncertain	0.60
Sift	Benign	0.12	T;T
Sift4G	Uncertain	0.051	T;D
Vest4		0.58
MutPred		0.95		Loss of ubiquitination at K57 (P = 0.1113);.;
MVP		1.0
MPC		1.8
ClinPred		0.97	D
GERP RS		-8.3
gMVP		0.97

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

LitVar

Other links and lift over

dbSNP: rs41378349; hg19: chr16-223205;