GENETIC-MAPPING OF HPH2, A MUTATION AFFECTING AMINO-ACID-TRANSPORT INTHE MOUSE

We describe the genetic mapping of hyperphenylalaninemia 2 (hph2), a r ecessive mutation in the mouse that causes deficient amino acid transp ort similar to Hartnup Disorder, a human genetic amino acid transport disorder. The hph2 locus was mapped in three separate crosses to ident ify candidate genes for hph2 and a region of homology in the human gen ome where we propose the Hartnup Disorder gene might lie. The mutation maps to mouse Chromosome (Chr) 7 distal of the simple sequence length polymorphism (SSLP) marker D7Mit140 and does not recombine with D7Nds 4, an SSLP marker in the fibroblast growth factor 3 (Fgf3) gene. Unexp ectedly, the mutant chromosome affects recombination frequency in the D7Mit12 to D7Nds4 interval.