Kidd Blood Group System

dadamowiki

A wikipedia of Dr. D'Adamo's research

Kidd Blood Group System JK Gene locus - SLC14A1 Alleles

C O N T E N T S

Am J Hum Genet. 1983 Nov;35(6):1190-5. Kivlin JD, Lovrien EW, Bishop DT, Maumenee IH.

A kindred of German descent was studied for dominant optic atrophy, type Kjer (McKusick catalog no. 16540). One hundred twenty-three family members were examined clinically, and 36 affected, 81 normal, and six uncertain members were ascertained. Twenty-seven markers were analyzed for 121 members. The maximum lod score obtained was 2.0 at theta = .18 for linkage between the Kidd locus and dominant optic atrophy. Twenty-eight offspring were informative with 2-generation data. There was insufficient information for the acid phosphatase locus to aid gene localization. These data suggest that the locus for dominant optic atrophy is on chromosome 2.

Nephrologie. 1996;17(7):383-8. Ripoche P, Rousselet G.

Water and urea use different pathways to cross biological membranes: channels and carriers. Numerous water channels were cloned (aquaporins); only two urea transporters are characterized in mammalians (UT2 and UT11) with sequence homologies suggesting two different carriers. This was confirmed by different localizations: UT2 was only found in renal medulla and probably was the AVP-sensitive urea carrier while UT11 was found in testis, spleen, brain and kidney and represents the constitutive urea carrier described in red blood cell. UT2 hybridized two transcripts, 4.1 kb and 2.9 kb. The large transcript expression was regulated by low protein diet whereas the short transcript was regulated by hydratation conditions. The heterologous expression into Xenopus oocytes showed a large increase of the urea uptake (UT2 > UT11), inhibitable by phloretin for UT11 and UT2 and by pCMBS only for UT11. A saturable transport of thiourea was only observed into oocytes expressing UT11. Moreover, hUT11 is encoded by the kidd locus, but, Jk (a-b-) individuals, in the absence of this urea transporter did not present related pathology. Other carriers still have to be identified and characterized in different renal segments and other tissues.

Br J Haematol. 2002 Feb;116(2):445-53.

Irshaid NM, Eicher NI, Hustinx H, Poole J, Olsson ML.

The Kidd (JK) blood group system is of importance in transfusion medicine. The Jk(null) phenotype is associated with absence of the urea transporter in erythrocytes and moderately reduced ability to concentrate urine. We and others recently reported different molecular alterations in the silenced Jkb-like alleles of Polynesians and Finns, populations with higher Jk(null) frequencies. Here we report novel molecular bases of this phenotype in Caucasians. Blood samples from a Swiss and an English family were investigated by serological methods, urea haemolysis test and JK genotyping. Genomic DNA and JK mRNA were sequenced. Genotyping showed homozygosity for Jka-like alleles. The Swiss Jk(null) alleles deviated from wild-type Jka sequence by a nonsense mutation in exon 7 causing an immediate stop codon (Tyr194stop). The English Jk(null) alleles revealed a genomic 1.6 kilobase pair deletion including exons 4 and 5, the former of which includes the translation start codon. Multiple mRNA splicing variants were detected in reticulocytes but exons 3-5 were absent in all transcripts analysed. Screening for these alleles was negative in random donors. Two novel molecular alterations at the JK locus were defined and a multiplex polymerase chain reaction method for detection of the five known silent Jk alleles was developed to complement JK genotyping in clinical transfusion medicine.