rs33984621

Variant names:

• chr16-177119-C-A
• rs33984621
• NM_000558.5:c.286C>A

Your query was ambiguous. Multiple possible variants found:

• chr16-177119-C-A
• chr16-177119-C-G
• chr16-177119-C-T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000558.5(HBA1):​c.286C>A​(p.Pro96Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. P96R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: HBA1 NM_000558.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 7.15
• Publications: 4 publications found

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]

HBA1 Gene-Disease associations (from GenCC):

• alpha thalassemia spectrum

  Inheritance: AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• erythrocytosis, familial, 7

  Inheritance: AD Classification: STRONG Submitted by: 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
• methemoglobinemia, alpha type

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• Heinz body anemia

  Inheritance: AR Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ENSG00000294436 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 24 uncertain in NM_000558.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-177120-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 15730.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000558.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HBA1	NM_000558.5	MANE Select	c.286C>A	p.Pro96Thr	missense	Exon 2 of 3	NP_000549.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HBA1	ENST00000320868.9	TSL:1 MANE Select	c.286C>A	p.Pro96Thr	missense	Exon 2 of 3	ENSP00000322421.5
	HBA1	ENST00000472694.1	TSL:1	n.422C>A		non_coding_transcript_exon	Exon 1 of 2
	HBA1	ENST00000487791.1	TSL:1	n.255C>A		non_coding_transcript_exon	Exon 2 of 2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1413234 Hom.: 0 Cov.: 28 AF XY: 0.00 AC XY: 0 AN XY: 701604

African (AFR) AF: 0.00 AC: 0 AN: 32500

American (AMR) AF: 0.00 AC: 0 AN: 40236

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25530

East Asian (EAS) AF: 0.00 AC: 0 AN: 38050

South Asian (SAS) AF: 0.00 AC: 0 AN: 82896

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 42228

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4216

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1088868

Other (OTH) AF: 0.00 AC: 0 AN: 58710

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not specified (1)
-	-	-	HEMOGLOBIN GODAVARI (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.37	T
Eigen	Uncertain	0.39
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.92	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.89	D
PhyloP100		7.2
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-7.6	D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Vest4		0.91
MutPred		0.96		Loss of ubiquitination at K91 (P = 0.1139)
MVP		1.0
ClinPred		1.0	D
GERP RS		4.3
PromoterAI		0.0046	Neutral
Varity_R		0.98
gMVP		0.96

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

Other links and lift over

dbSNP: rs33984621; hg19: chr16-227118;