11-5226702-G-A
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000518.5(HBB):c.190C>T(p.His64Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H64R) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000518.5 missense
Scores
Clinical Significance
Conservation
Publications
- dominant beta-thalassemiaInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
- hemoglobin M diseaseInheritance: AD Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, ClinGen
- beta thalassemiaInheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
- beta-thalassemia HBB/LCRBInheritance: AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- sickle cell disease and related diseasesInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- erythrocytosis, familial, 6Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- Heinz body anemiaInheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- sickle cell diseaseInheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
- hereditary persistence of fetal hemoglobin-beta-thalassemia syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- beta-thalassemia intermediaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- beta-thalassemia majorInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- delta-beta-thalassemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin C diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin C-beta-thalassemia syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin E diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hemoglobin E-beta-thalassemia syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hereditary persistence of fetal hemoglobin-sickle cell disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-beta-thalassemia disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-hemoglobin c disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-hemoglobin d disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sickle cell-hemoglobin E disease syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| HBB | NM_000518.5 | c.190C>T | p.His64Tyr | missense_variant | Exon 2 of 3 | ENST00000335295.4 | NP_000509.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| HBB | ENST00000335295.4 | c.190C>T | p.His64Tyr | missense_variant | Exon 2 of 3 | 1 | NM_000518.5 | ENSP00000333994.3 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 36
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
beta Thalassemia Pathogenic:2
Variant summary: HBB c.190C>T (p.His64Tyr) results in a conservative amino acid change located in a heme binding site (InterPro) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251426 control chromosomes (gnomAD). The variant (also known as Hb M-Saskatoon) is widely regarded as causing hemoglobin M (HbM) disease, and has been reported in the literature in several affected individuals (e.g. Efremov_1974, Waye_1994, Suryantoro_1995, Kedar_2005, Brunner-Agten_2010, Garcia-Morin_2019). The disorder was observed to be inherited in an autosomal dominant pattern, often occurring as a de novo mutation. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic.
not provided Pathogenic:2
The HBB c.190C>T (p.His64Tyr) variant (also known as Hb M Saskatoon and H63Y) has been reported in the published literature in individuals/families affected with autosomal dominant methemoglobinemia (PMIDs: 34789072 (2021), 30828177 (2019), 4841979 (1974), 13897827 (1961), 20324533 (1950)) or hemoglobinopathy (PMID: 32830468 (2020)) and has been observed to occur de novo (PMIDs: 19727720 (2010), 15929117 (2005), 7713749 (1994)). Functional studies have reported that this variant is damaging to the natural function of beta globin with increased oxygen affinity, increased auto-oxidation, and reduced stability (PMIDs: 30828177 (2019), 15929117 (2005), 4086306 (1985), 7372598 (1980), 6248489 (1980), 4301455 (1968), 5851873 (1965)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as pathogenic and is associated with autosomal dominant methemoglobinemia.
The Hb M-Saskatoon variant (HBB: c.190C>T; p.His64Tyr, also known as His63Tyr when numbered from the mature protein, rs33922873, HbVar ID: 359) is reported in the literature in several individuals with hemoglobin M (HbM) disease (Arbane-Dahmane 1985, Bouatrous 2021, Brunner-Agten 2010, Gottgens 2021, Suryantoro 1995, Waye 1994). HbM disease is an autosomal dominantly inherited congenital form of methemoglobinemia, and pathogenic variants often occur de novo (Bouatrous 2021, Brunner-Agten 2010, Waye 1994). This variant is reported in ClinVar (Variation ID: 15256). It is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. Computational analyses predict that this variant is deleterious (REVEL: 0.942). Based on available information, the Hb M-Saskatoon variant is considered to be pathogenic for HbM disease. References: Link to HbVar database: https://globin.bx.psu.edu/hbvar/menu.html Arbane-Dahmane M et al. Hemoglobin M Saskatoon (alpha 2 beta 2 63(E7) His----Tyr) in an Algerian family. Hemoglobin. 1985;9(5):509-11. PMID: 4086306. Bouatrous E et al. First Observation of HbM-Saskatoon at the Origin of Neonatal Cyanosis in a Tunisian Baby. J Pediatr Hematol Oncol. 2021 Nov 1;43(8):e1055-e1058. PMID: 33625083. Brunner-Agten S et al. Compound heterozygosity of Hb Hamilton and de novo mutated HbM Saskatoon. Ann Hematol. 2010 May;89(5):517-8. PMID: 19727720. Gottgens EL et al. Cyanosis, hemolysis, decreased HbA1c and abnormal co-oximetry in a patient with hemoglobin M Saskatoon (HBB:c.190C?>?T p.His64Tyr). Hematology. 2021 Dec;26(1):914-918. PMID: 34789072. Suryantoro P et al. C to T transition at the first nucleotide of codon 63 of the beta-globin gene corresponding to hemoglobin M-Saskatoon in an Indonesian boy. Jpn J Hum Genet. 1995 Jun;40(2):195-201. PMID: 7663000. Waye JS et al. De novo beta-globin gene mutation (beta 63(E7)His-->Tyr) giving rise to Hb M disease in a Newfoundlander. Hemoglobin. 1994 Nov;18(6):441-3. PMID: 7713749.
Inborn genetic diseases Pathogenic:1
HEMOGLOBIN M (RADOM) METHEMOGLOBINEMIA, BETA TYPE Pathogenic:1
METHEMOGLOBINEMIA, BETA TYPE Pathogenic:1
HEMOGLOBIN M (SASKATOON) Other:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at