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UniProtKB/Swiss-Prot P69892: Variant p.Val68Met

Hemoglobin subunit gamma-2
Gene: HBG2
Variant information

Variant position:  68
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  LP/P [Disclaimer]
The variants are classified into three categories: LP/P, LB/B and US.
  • LP/P: likely pathogenic or pathogenic.
  • LB/B: likely benign or benign.
  • US: uncertain significance

Residue change:  From Valine (V) to Methionine (M) at position 68 (V68M, p.Val68Met).
Indicates the amino acid change of the variant. The one-letter and three-letter codes for amino acids used in UniProtKB/Swiss-Prot are those adopted by the commission on Biochemical Nomenclature of the IUPAC-IUB.

Physico-chemical properties:  Similar physico-chemical property. Both residues are medium size and hydrophobic.
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  1
The score within a Blosum matrix for the corresponding wild-type to variant amino acid change. The log-odds score measures the logarithm for the ratio of the likelihood of two amino acids appearing by chance. The Blosum62 substitution matrix is used. This substitution matrix contains scores for all possible exchanges of one amino acid with another:
  • Lowest score: -4 (low probability of substitution).
  • Highest score: 11 (high probability of substitution).
More information can be found on the following page

Variant description:  In TNCY; hemoglobin Toms River; the side chain of methionine decreases both the affinity of oxygen for binding to the mutant hemoglobin subunit via steric hindrance and the rate at which it does so; the mutant methionine is converted to aspartic acid post-translationally.
Any additional useful information about the variant.

Other resources:  
Links to websites of interest for the variant.



Sequence information

Variant position:  68
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  147
The length of the canonical sequence.

Location on the sequence:   NLSSASAIMGNPKVKAHGKK  V LTSLGDAIKHLDDLKGTFAQ
The residue change on the sequence. Unless the variant is located at the beginning or at the end of the protein sequence, both residues upstream (20) and downstream (20) of the variant will be shown.

Sequence annotation in neighborhood:  
The regions or sites of interest surrounding the variant. In general the features listed are posttranslational modifications, binding sites, enzyme active sites, local secondary structure or other characteristics reported in the cited references. The "Sequence annotation in neighborhood" lines have a fixed format:
  • Type: the type of sequence feature.
  • Positions: endpoints of the sequence feature.
  • Description: contains additional information about the feature.

TypePositionsDescription
Chain 2 – 147 Hemoglobin subunit gamma-2
Metal binding 64 – 64 Iron (heme distal ligand)
Modified residue 51 – 51 Phosphoserine
Modified residue 53 – 53 Phosphoserine
Modified residue 60 – 60 N6-acetyllysine
Modified residue 83 – 83 N6-acetyllysine
Helix 59 – 76


Literature citations

A hemoglobin variant associated with neonatal cyanosis and anemia.
Crowley M.A.; Mollan T.L.; Abdulmalik O.Y.; Butler A.D.; Goodwin E.F.; Sarkar A.; Stolle C.A.; Gow A.J.; Olson J.S.; Weiss M.J.;
N. Engl. J. Med. 364:1837-1843(2011)
Cited for: VARIANT TNCY MET-68; CHARACTERIZATION OF VARIANT TNCY MET-68;

Disclaimer: Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. They are not in any way intended to be used as a substitute for professional medical advice, diagnostic, treatment or care.