Canine Imerslund-Gräsbeck syndrome maps to a region orthologous to HSA14q.
Selective malabsorption of cobalamin (vitamin B(12)) accompanied by proteinuria, known as Imerslund-Gräsbeck syndrome or megaloblastic anemia 1 (I-GS, MGA1; OMIM 261100), is a rare autosomal recessive disorder. In Finnish kindreds, I-GS is caused by mutations in the cubilin gene ( CUBN), located on human Chromosome (Chr) 10. However, not all patients have CUBN mutations, and three distinct mutations in the amnionless gene, AMN, were very recently identified in patients from Norwegian and Israeli families. The present study demonstrates that in a large canine I-GS pedigree, the disease is genetically linked (peak multipoint LOD score 11.74) to a region on dog Chr 8 that exhibits conserved synteny with human Chr 14q. Multipoint analysis indicates that the canine disease gene lies in an interval between the echinoderm microtubule-associated, protein-like 1 ( EML1) gene and the telomere. A single critical recombinant further suggests that the disease gene is between markers in EML1 and the G protein-coupled receptor ( G2A) gene, defining an I-GS interval in the human genome that contains the AMN gene. Thus, these comparative-mapping data provide evidence that canine I-GS is a homologue of one form of the human disease and will provide a useful system for understanding the molecular mechanisms underlying the disease in humans.
He
Qianchuan
Q
Laboratory of Comparative Medical Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48824, USA.
Fyfe
John C
JC
Schäffer
Alejandro A
AA
Kilkenney
Adam
A
Werner
Petra
P
Kirkness
Ewen F
EF
Henthorn
Paula S
PS
D000749:Anemia, Megaloblastic / Q000235:genetics / Q000662:veterinary*; D000818:Animals; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics*; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D017931:DNA Primers; D030541:Databases, Genetic; D004283:Dog Diseases / Q000235:genetics*; D004285:Dogs; D005838:Genotype; D006801:Humans; D008126:Lod Score; D008565:Membrane Proteins; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011506:Proteins; D026801:Synteny
C484714:AMN protein, human; D017931:DNA Primers; D008565:Membrane Proteins; D011506:Proteins