rs33914944

chr11-5226577-C-Achr11-5226577-C-Gchr11-5226577-C-Nchr11-5226577-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_000518.5(HBB):c.315G>T(p.Arg105Ser) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,736 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R105?) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: HBB NM_000518.5 missense, splice_region
• Scores: Splicing: ADA: 0.9981
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.59

Genes affected

HBB (HGNC:4827): (hemoglobin subunit beta) The alpha (HBA) and beta (HBB) loci determine the structure of the 2 types of polypeptide chains in adult hemoglobin, Hb A. The normal adult hemoglobin tetramer consists of two alpha chains and two beta chains. Mutant beta globin causes sickle cell anemia. Absence of beta chain causes beta-zero-thalassemia. Reduced amounts of detectable beta globin causes beta-plus-thalassemia. The order of the genes in the beta-globin cluster is 5'-epsilon -- gamma-G -- gamma-A -- delta -- beta--3'. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 15 uncertain in NM_000518.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HBB	NM_000518.5	c.315G>T	p.Arg105Ser	missense_variant, splice_region_variant	2/3	ENST00000335295.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HBB	ENST00000335295.4	c.315G>T	p.Arg105Ser	missense_variant, splice_region_variant	2/3	1	NM_000518.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461736 Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1 AN XY: 727198

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Nov 15, 2016

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.40
Cadd	Pathogenic	26
Dann	Uncertain	0.99
DEOGEN2	Benign	0.052	T;T;.
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.92	D
M_CAP	Pathogenic	0.48	D
MetaRNN	Pathogenic	0.90	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.5	H;H;.
MutationTaster	Benign	1.0	D
PrimateAI	Benign	0.34	T
PROVEAN	Uncertain	-3.5	D;.;.
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D;.;.
Sift4G	Uncertain	0.0020	D;.;.
Polyphen		0.20	B;B;.
Vest4		0.68
MutPred		0.73		Loss of methylation at R105 (P = 0.0754);Loss of methylation at R105 (P = 0.0754);Loss of methylation at R105 (P = 0.0754);
MVP		0.97
MPC		0.20
ClinPred		0.99	D
GERP RS		3.8
Varity_R		0.77
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.040		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: rs33914944; hg19: chr11-5247807;