Positional candidate genes for congenital chloride diarrhea suggested by high-resolution physical mapping in chromosome region 7q31.
Congenital chloride diarrhea affects intestinal transportation of electrolytes, resulting in potentially fatal diarrhea. Linkage disequilibrium analyses have suggested the congenital chloride diarrhea gene (CLD) to lie within 0.37 cM from D7S496 in human chromosome 7q31. To clone the CLD gene, we have constructed and refined a physical map based on a 2.7-Mb YAC contig around D7S496 and identified two candidate genes. The physical positions of 4 known genes (DRA, PRKAR2B, LAMB1, DLD), 7 polymorphic repeat markers, and 13 CpG islands were established. DRA (down-regulated in adenoma) is expressed in the gut and encodes a protein with sequence homology to anion transporters, whereas PRKAR2B encodes a regulatory subunit for protein kinase A. Both genes map within 450 kb from D7S496, making them functionally and positionally relevant candidates for CLD.
Höglund
P
P
Department of Medical Genetics, University of Helsinki, Finland. pia.hoglund@helsinki.fi
Haila
S
S
Scherer
S W
SW
Tsui
L C
LC
Green
E D
ED
Weissenbach
J
J
Holmberg
C
C
de la Chapelle
A
A
Kere
J
J
D001483:Base Sequence; D002712:Chlorides / Q000378:metabolism*; D002874:Chromosome Mapping; D018244:Chromosomes, Artificial, Yeast / Q000737:chemistry; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D000013:Congenital Abnormalities / Q000235:genetics*; D015342:DNA Probes; D003967:Diarrhea / Q000151:congenital / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping
D002712:Chlorides; D015342:DNA Probes; D005819:Genetic Markers