11-5226954-T-C
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2PM5BP6
The NM_000518.5(HBB):āc.68A>Gā(p.Glu23Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,524 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E23K) has been classified as Likely benign.
Frequency
Consequence
NM_000518.5 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Uncertain_significance. Variant got 3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461524Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1AN XY: 727106
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
not provided Uncertain:1Benign:1
It has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). In the published literature, the variant is associated with normal clinical presentation when in heterozygosity (PMIDs: 3623978 (1987) and 23806067 (2013)). It has also been identified as a common variant in China, seen in a subject with reduced mean corpuscular volume levels from a routine blood analysis, and among subjects with hemoglobin disorders (PMIDs: 29626415 (2018), 26950205 (2016), and 25849334 (2015)). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
The Hb G-Taipei variant (HBB: c.68A>G; p.Glu23Gly, also known as Glu22Gly when numbered from the mature protein, rs33936254, HbVar ID: 265) is reported in the heterozygous state in asymptomatic individuals with normal hematological parameters (Lin 2013, Zhang 2015, Zhang 2017, HbVar and references therein). This variant has not been reported with a pathogenic variant on the opposite chromosome, although, other variants at this codon (Glu22Ala, Glu22Gln) exhibit no clinical symptoms when found with a beta0 pathogenic variant in trans (Agrawal 2007, Koseler 2013, Rohe 1973). The Hb G-Taipei variant is listed in ClinVar (Variation ID: 15178). It is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. Computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.59). Based on available information, the Hb G-Taipei variant is considered to be likely benign. References: HbVar database link: https://globin.bx.psu.edu/hbvar/menu.html Agrawal M et al. Compound heterozygosity of Hb D(Iran) (beta(22) Glu-->Gln) and beta(0)-thalassemia (619 bp-deletion) in India. Eur J Haematol. 2007 Sep;79(3):248-50. PMID: 17655708. Koseler A et al. Molecular studies on the origin of the Hb G-Coushatta mutation in Denizli province of Turkey. Biochem Genet. 2013; 51(1-2):71-5. PMID: 23001606. Lin M et al. Molecular epidemiological survey of hemoglobinopathies in the Wuxi region of Jiangsu Province, eastern China. Hemoglobin. 2013;37(5):454-66. PMID: 23806067. Rohe R et al. Hemoglobin D Iran alpha A2 beta 22 2-Glu leads to Gln in association with thalassemia. Blood. 1973 Sep;42(3):455-62. PMID: 4725603. Zhang J et al. Genetic heterogeneity of the B-globin gene in various geographic populations of Yunnan in southwestern China. PLoS One. 2015 Apr 7;10(4):e0122956. PMID: 25849334. Zhang XM et al. Effects of hemoglobin variants HbJ Bangkok, HbE, HbG Taipei, and HbH on analysis of glycated hemoglobin via ion-exchange high-performance liquid chromatography. J Clin Lab Anal. 2017 Apr 13. PMID: 28407371. -
HEMOGLOBIN G (TAIPEI) Other:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at