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UniProtKB/Swiss-Prot P09848: Variant p.Val219Ile

Lactase-phlorizin hydrolase
Gene: LCT
Variant information

Variant position:  219
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Polymorphism
The variants are classified into three categories: Disease, Polymorphism and Unclassified.
  • Disease: Variants implicated in disease according to literature reports.
  • Polymorphism: Variants not reported to be implicated in disease.
  • Unclassified: Variants with uncertain implication in disease according to literature reports. Evidence against or in favor of a pathogenic role is limited and/or conflicting.

Residue change:  From Valine (V) to Isoleucine (I) at position 219 (V219I, p.Val219Ile).
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:  3
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

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



Sequence information

Variant position:  219
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  1927
The length of the canonical sequence.

Location on the sequence:   HRKAYEIYHESYAFQGGKLS  V VLRAEDIPELLLEPPISALA
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.

Residue conservation: 
The multiple alignment of the region surrounding the variant against various orthologous sequences.

Human                         HRKAYEIYHESYAFQGGKLSVVLRAEDIPELLLEPPISALA

Rat                           HRRAFEIYHRKFSSQGGKLSVVLKAEDIPELLPDPALAALV

Rabbit                        HRKAYEIYHQKYAAQGGKVSVVLQAEEISELLLESSTSALA

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
Propeptide 20 – 868 Beta-glucosidase
Topological domain 20 – 1882 Extracellular
Region 87 – 1841 4 X approximate repeats


Literature citations

Structure of the chromosomal gene and cDNAs coding for lactase-phlorizin hydrolase in humans with adult-type hypolactasia or persistence of lactase.
Boll W.; Wagner P.; Mantei N.;
Am. J. Hum. Genet. 48:889-902(1991)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]; VARIANTS ILE-219; VAL-362 AND SER-1639;

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.