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UniProtKB/Swiss-Prot P29033: Variant p.Asp50Asn

Gap junction beta-2 protein
Gene: GJB2
Variant information

Variant position:  50
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 Aspartate (D) to Asparagine (N) at position 50 (D50N, p.Asp50Asn).
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:  Change from medium size and acidic (D) to medium size and polar (N)
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 KIDAD and HID syndrome.
Any additional useful information about the variant.

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

Sequence information

Variant position:  50
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  226
The length of the canonical sequence.

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.








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.

Chain 1 – 226 Gap junction beta-2 protein
Topological domain 41 – 73 Extracellular
Metal binding 42 – 42 Calcium; shared with neighboring subunit
Metal binding 45 – 45 Calcium; via carbonyl oxygen
Metal binding 47 – 47 Calcium
Mutagenesis 34 – 34 M -> A. Loss of gap junction ion conductance, probably due to very low open probability of the channels. Can form functional channels with wild-type, but with strongly reduced channel conductance. No visible effect on channel assembly and membrane insertion.
Turn 47 – 50

Literature citations

Missense mutations in GJB2 encoding connexin-26 cause the ectodermal dysplasia keratitis-ichthyosis-deafness syndrome.
Richard G.; Rouan F.; Willoughby C.E.; Brown N.; Chung P.; Ryynanen M.; Jabs E.W.; Bale S.J.; DiGiovanna J.J.; Uitto J.; Russell L.;
Am. J. Hum. Genet. 70:1341-1348(2002)
Cited for: VARIANTS KIDAD ARG-12; PHE-17 AND ASN-50;

HID and KID syndromes are associated with the same connexin 26 mutation.
van Geel M.; van Steensel M.A.M.; Kuester W.; Hennies H.C.; Happle R.; Steijlen P.M.; Koenig A.;
Br. J. Dermatol. 146:938-942(2002)

De novo mutation in the gene encoding connexin-26 (GJB2) in a sporadic case of keratitis-ichthyosis-deafness (KID) syndrome.
Alvarez A.; Del Castillo I.; Pera A.; Villamar M.; Moreno-Pelayo M.A.; Moreno F.; Moreno R.; Tapia M.C.;
Am. J. Med. Genet. A 117:89-91(2003)
Cited for: VARIANT KIDAD ASN-50;

Novel mutations in GJB2 encoding connexin-26 in Japanese patients with keratitis-ichthyosis-deafness syndrome.
Yotsumoto S.; Hashiguchi T.; Chen X.; Ohtake N.; Tomitaka A.; Akamatsu H.; Matsunaga K.; Shiraishi S.; Miura H.; Adachi J.; Kanzaki T.;
Br. J. Dermatol. 148:649-653(2003)

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.