rs33929415
Variant summary
Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PM2BP6_Very_Strong
The NM_000518.5(HBB):c.430C>T(p.His144Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,613,976 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H144D) has been classified as Likely benign.
Frequency
Consequence
NM_000518.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152142Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251382Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135864
GnomAD4 exome AF: 0.00000821 AC: 12AN: 1461834Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7AN XY: 727234
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152142Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1AN XY: 74330
ClinVar
Submissions by phenotype
not specified Benign:2
Variant summary: HBB c.430C>T [p.His144Tyr; also known as Hb Old Dominion/Burton-upon-Trent (OD/BuT) and as legacy name p.His143Tyr] results in a conservative amino acid change located in the Globin domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251382 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.430C>T has been reported in the literature in multiple individuals with diabetes mellitus who were identified as having an abnormal hemoglobin that co-elutes with hemoglobinA1c, but had no other evidence of hemoglobinopathy (e.g. Elder_1998, Gilbert_2000, Plaseska-Karanfilska_2000). These findings indicate that the variant is unlikely to be associated with hemoglobin-related disease. The only potential clinical consequence that has been observed for this variant is that it co-elutes with HbAlc on ion exchange chromatography and thereby causes a spurious increase in HbAlc, compromising the utility of this test to monitor the treatment of diabetes mellitus in individuals with the variant. At least one publication reports experimental evidence evaluating an impact on protein function, indicating that the variant had a slight increase in oxygen affinity that did not appear to result in a clinical impact (e.g. Elder_1998). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as likely benign. -
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not provided Benign:1
The Hb Old Dominion/Burton-upon-Trent variant (HBB: c.430C>T; p.His144Tyr, also known as His143Tyr when numbered from the mature protein, HbVar ID: 566, rs33929415) is reported in the literature in multiple heterozygous individuals with normal hematology (Elder 1998, HbVar and references therein). This variant is only observed on one allele in the Genome Aggregation Database, indicating it is not a common polymorphism. The histidine at codon 144 is highly conserved, but computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.653). Functional analyses indicate only a slightly increased oxygen affinity that does not correlate with clinical or hematological symptoms (Elder 1998). However, this variant has been reported to interfere with measurement of HbA1c by some methodologies (Elder 1998). Based on available information, including its presence in multiple clinically unaffected individuals, this variant is considered to be likely benign. REFERENCES Link to HbVar database: https://globin.bx.psu.edu/hbvar/menu.html Elder GE et al. Hemoglobin Old Dominion/Burton-upon-Trent, beta 143 (H21) His-->Tyr, codon 143 CAC-->TAC--a variant with altered oxygen affinity that compromises measurement of glycated hemoglobin in diabetes mellitus: structure, function, and DNA sequence. Mayo Clin Proc. 1998 Apr;73(4):321-8. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at