16-176733-CCGA-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PM4_Supporting

The NM_000558.5(HBA1):​c.19_21del​(p.Asp7del) variant causes a inframe deletion change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 28)

Consequence

HBA1
NM_000558.5 inframe_deletion

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.77
Variant links:
Genes affected
HBA1 (HGNC:4823): (hemoglobin subunit alpha 1) 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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM4
Nonframeshift variant in NON repetitive region in NM_000558.5. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
HBA1NM_000558.5 linkuse as main transcriptc.19_21del p.Asp7del inframe_deletion 1/3 ENST00000320868.9 NP_000549.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
HBA1ENST00000320868.9 linkuse as main transcriptc.19_21del p.Asp7del inframe_deletion 1/31 NM_000558.5 ENSP00000322421 P1
HBA1ENST00000472694.1 linkuse as main transcriptn.38_40del non_coding_transcript_exon_variant 1/21
HBA1ENST00000397797.1 linkuse as main transcriptc.-29_-27del 5_prime_UTR_variant 1/32 ENSP00000380899
HBA1ENST00000487791.1 linkuse as main transcript upstream_gene_variant 1

Frequencies

GnomAD3 genomes
Cov.:
28
We have no GnomAD4 exomes data on this position. Probably position not covered by the project.
GnomAD4 genome
Cov.:
28

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesMay 16, 2019The Hb Boyle Heights variant (HBA1: c.19_21delGAC; p.Asp7del, also known as Asp6del when numbered from the mature protein; rs281865565) has been previously reported in the medical literature in a heterozgyous individual without substantial clinical symptoms (HbVar database and references therein). This variant is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. The variant protein is considered unstable, and shows increased oxygen affinity (HbVar database and references therein). The variant is predicted to result in an in-frame deletion of the aspartate at residue 7. Due to the limited information regarding this variant, its clinical significance could not be determined with certainty. References: Link to HbVar database for Hb Boyle Heights: http://globin.bx.psu.edu/cgi-bin/hbvar/query_vars3?mode=output&display_format=page&i=715 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs281865565; hg19: chr16-226732; API