rs34264694

Positions:

• chr11-5254408-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 8P and 3B. PM1 PM2 PP3_Strong BP6_Moderate BS2_Supporting

The ENST00000336906.6(HBG2):​c.199A>C​(p.Lys67Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,892 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 Likely benign (★). Another nucleotide change resulting in same amino acid change has been previously reported as Likely benignin UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K67R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: HBG2 ENST00000336906.6 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1 O:1
• Conservation: PhyloP100: 3.00

Genes affected

HBG2 (HGNC:4832): (hemoglobin subunit gamma 2) The gamma globin genes (HBG1 and HBG2) are normally expressed in the fetal liver, spleen and bone marrow. Two gamma chains together with two alpha chains constitute fetal hemoglobin (HbF) which is normally replaced by adult hemoglobin (HbA) at birth. In some beta-thalassemias and related conditions, gamma chain production continues into adulthood. The two types of gamma chains differ at residue 136 where glycine is found in the G-gamma product (HBG2) and alanine is found in the A-gamma product (HBG1). The former is predominant at birth. 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 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in ENST00000336906.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.964
• BP6: Variant 11-5254408-T-G is Benign according to our data. Variant chr11-5254408-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 14987.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAdExome4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HBG2	NM_000184.3	c.199A>C	p.Lys67Gln	missense_variant	2/3	ENST00000336906.6	NP_000175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HBG2	ENST00000336906.6	c.199A>C	p.Lys67Gln	missense_variant	2/3	1	NM_000184.3	ENSP00000338082	P1
HBG2	ENST00000380252.6	c.34A>C	p.Lys12Gln	missense_variant	2/3	3		ENSP00000369602
HBG2	ENST00000444587.1	c.*68A>C		3_prime_UTR_variant	2/3	2		ENSP00000488218

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461892 Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely benign

Submissions summary: Benign:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Jul 02, 2021

- -

HEMOGLOBIN F (BROOKLYN) Other:1

other, no assertion criteria provided

literature only

OMIM

Aug 05, 2011

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Benign	0.0018	T
BayesDel_noAF	Uncertain	-0.040
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.12	.;.;T;.
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.98	D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.96	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	.;.;H;.
MutationTaster	Benign	0.93	D;D;D
PROVEAN	Uncertain	-3.6	.;.;D;.
REVEL	Uncertain	0.60
Sift	Pathogenic	0.0	.;.;D;.
Sift4G	Uncertain	0.0080	.;.;D;.
Polyphen		1.0	.;.;D;.
Vest4		0.60
MutPred		0.92		Gain of catalytic residue at K67 (P = 0.0412);Gain of catalytic residue at K67 (P = 0.0412);Gain of catalytic residue at K67 (P = 0.0412);.;
MVP		0.97
ClinPred		0.98	D
GERP RS		4.0
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		3.0
Varity_R		0.95
gMVP		0.61

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: rs34264694; hg19: chr11-5275638;