rs1455865276

Positions:

• chr16-173698-T-C

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_Strong BP6

The NM_000517.6(HBA2):​c.*98T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,508,844 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 25)
  • Exomes 𝑓: 0.000018 (1 hom.)
• Consequence: HBA2 NM_000517.6 3_prime_UTR
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.162

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]

(HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).
• BP6: Variant 16-173698-T-C is Benign according to our data. Variant chr16-173698-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 439111.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HBA2	NM_000517.6	c.*98T>C		3_prime_UTR_variant	3/3	ENST00000251595.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HBA2	ENST00000251595.11	c.*98T>C		3_prime_UTR_variant	3/3	1	NM_000517.6	P1
HBA2	ENST00000397806.1	c.*98T>C		3_prime_UTR_variant	3/3	2
	ENST00000702607.1			upstream_gene_variant
HBA2	ENST00000482565.1			downstream_gene_variant		1

Frequencies

GnomAD3 genomes AF: 0.0000201 AC: 3 AN: 149168 Hom.: 0 Cov.: 25

Gnomad AFR AF: 0.0000258

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000184 AC: 25 AN: 1359676 Hom.: 1 Cov.: 22 AF XY: 0.0000177 AC XY: 12 AN XY: 677780

Gnomad4 AFR exome AF: 0.0000367

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000212

Gnomad4 SAS exome AF: 0.000100

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000675

Gnomad4 OTH exome AF: 0.0000178

GnomAD4 genome AF: 0.0000201 AC: 3 AN: 149168 Hom.: 0 Cov.: 25 AF XY: 0.0000412 AC XY: 3 AN XY: 72756

Gnomad4 AFR AF: 0.0000258

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Nov 03, 2020

- -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Mar 27, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	7.6
DANN	Benign	0.67

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: rs1455865276; hg19: chr16-223697;