|Blood Group Antigen Gene Mutation Database|
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Kidd Blood Group System
Gene locus - SLC14A1
The protein carrying the antigen for the Kidd blood group is a product of a single gene, SLC14A1 (Solute carrier family 14, member 1; previously known as JK,HUT11) of the urea-transporter gene family. It is an integral membrane glycoprotein with 10 membrane-spanning domains. As a urea transporter it may play a role in preserving the osmotic stability and deformability of the erythrocyte. The erythroid transporter gene bears 61% sequence identity to the human kidney urea transporter.
The gene is organized in 11 exons distributed over 30 kb. The mature 45-kd protein is encoded by exons 4-11. Chromosomal location of the SLC14A1 gene is 18q12-q21.
Function of proteins
erythocytes, white blood cells(?), kidney medulla (information still incomplete due to the existence of homologs)
Individuals lacking the expression of the Kidd blood antigen show a lack or reduced carrier-mediated urea transport and decreased ability for urine concentration (Sands et al. PMID 1498276)
So far, the molecular basis has been documented for only a few alleles; among them many specify the JK null phenotype and fail to express the protein on the red cells. This phenotype is rare, and has been observed in Asia, Polynesia and Finland.Red cells of Jk(a-b-) individuals are resistant to lysis by 2M urea, and that finding can be used as a screening test for this phenotype. The two alleles that encode the common antigens JKA and JKB ( also known as JK 01 and JK 02, respectively) differ at nucleotide 838 ( JKA , GAC=D , JKB, AAC=N); because of some discrepancies in the reference sequences used in different publications the numbering of nucleotides may also differ; here the JKB sequence acc. no. NM_015865.5 (version5; as of June 12 2013, version 6 is used) is used as reference.Note that for a number of alleles, the publication record does not always include sequencing results of the epitopic region (JKAvsJKB)
When searching for a particular allele, use "name" if DNA alteration is known or, if you wish to search by phenotype or the designation used by author, use "alias" (see "Details").
Other database IDs and links
Marion E. Reid
New York Blood Center
310 East 67 St
New York, N.Y.10021
Contributors for specific alleles are listed with the alleles.
Updated 2013-06-12 16:27:40.650