rs281864895

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000558.5(HBA1):​c.178G>A​(p.Gly60Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000134 in 149,440 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G60V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000034 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HBA1
NM_000558.5 missense

Scores

8
7
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.10
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HBA1NM_000558.5 linkc.178G>A p.Gly60Ser missense_variant Exon 2 of 3 ENST00000320868.9 NP_000549.1 P69905D1MGQ2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HBA1ENST00000320868.9 linkc.178G>A p.Gly60Ser missense_variant Exon 2 of 3 1 NM_000558.5 ENSP00000322421.5 P69905
HBA1ENST00000472694.1 linkn.314G>A non_coding_transcript_exon_variant Exon 1 of 2 1
HBA1ENST00000487791.1 linkn.147G>A non_coding_transcript_exon_variant Exon 2 of 2 1
HBA1ENST00000397797.1 linkc.82G>A p.Gly28Ser missense_variant Exon 2 of 3 2 ENSP00000380899.1 G3V1N2

Frequencies

GnomAD3 genomes
AF:
0.0000134
AC:
2
AN:
149440
Hom.:
0
Cov.:
31
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:
0.0000148
Gnomad OTH
AF:
0.000500
GnomAD3 exomes
AF:
0.00000736
AC:
1
AN:
135930
Hom.:
0
AF XY:
0.0000135
AC XY:
1
AN XY:
73964
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000188
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000336
AC:
4
AN:
1188900
Hom.:
0
Cov.:
17
AF XY:
0.00000503
AC XY:
3
AN XY:
596430
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000129
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000334
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000134
AC:
2
AN:
149440
Hom.:
0
Cov.:
31
AF XY:
0.0000137
AC XY:
1
AN XY:
72808
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000148
Gnomad4 OTH
AF:
0.000500
Bravo
AF:
0.0000151

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Nov 16, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The Hb Parma variant (HBA1 c.178G>A; p.Gly60Ser variant, also known as Gly59Ser when numbered from the mature protein, rs281864895, HbVar ID: 2581, ClinVar ID: 993066) to our knowledge, is not reported in the medical literature but is reported in an asymptomatic individual in the HbVar database (see HbVar database link). However, other variants at this codon in the homologous HBA2 gene (Hb Adana; c.179G>A;p.Gly60Asp and Hb Zurich Albisrieden; c.178G>C; p.Gly60Arg) have been reported in affected individuals are considered disease causing (Curuk 1993, Dutly 2004, see HbVar database and references therein). This variant is only observed on one allele in the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. Computational analyses predict that this variant is deleterious (REVEL: 0.899). However, given the lack of clinical and functional data, the significance of p.Gly60Ser variant is uncertain at this time. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/menu.html Curuk MA et al. Hb Adana or alpha 2(59)(E8)Gly-->Asp beta 2, a severely unstable alpha 1-globin variant, observed in combination with the -(alpha)20.5 Kb alpha-thal-1 deletion in two Turkish patients. Am J Hematol. 1993 Dec;44(4):270-5. PMID: 8237999. Dutly F et al. A new highly unstable alpha chain variant causing alpha(+)-thalassemia: Hb Zurich Albisrieden [alpha59(E8)Gly-->Arg (alpha2)]. Hemoglobin. 2004;28(4):347-51. PMID: 15658192. -

Mar 21, 2018
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.90
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.26
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.36
T;.
Eigen
Uncertain
0.25
Eigen_PC
Uncertain
0.24
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.84
T;T
M_CAP
Pathogenic
0.92
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
0.85
D
PrimateAI
Uncertain
0.60
T
PROVEAN
Pathogenic
-5.4
D;D
REVEL
Pathogenic
0.90
Sift
Uncertain
0.0010
D;D
Sift4G
Uncertain
0.0020
D;D
Vest4
0.93
MutPred
0.92
Gain of disorder (P = 0.0749);.;
MVP
1.0
ClinPred
0.99
D
GERP RS
4.3
Varity_R
0.94
gMVP
0.94

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: rs281864895; hg19: chr16-227010; API