A highly polymorphic dinucleotide repeat on the proximal short arm of the human X chromosome: linkage mapping of the synapsin I/A-raf-1 genes.
A compound (AC)n repeat located 1,000 bp downstream from the human synapsin I gene and within the last intron of the A-raf-1 gene has been identified. DNA data-base comparisons of the sequences surrounding the repeat indicate that the synapsin I gene and the A-raf-1 gene lie immediately adjacent to each other, in opposite orientation. PCR amplification of this synapsin I/A-raf-1 associated repeat by using total genomic DNA from members of the 40 reference pedigree families of the Centre d'Etude du Polymorphisme Humaine showed it to be highly polymorphic, with a PIC value of .84 and a minimum of eight alleles. Because the synapsin I gene has been mapped previously to the short arm of the human X chromosome at Xp11.2, linkage analysis was performed with markers on the proximal short arm of the X chromosome. The most likely gene order is DXS7SYN/ARAF1TIMPDXS255DXS146, with a relative probability of 5 x 10(8) as compared with the next most likely order. This highly informative repeat should serve as a valuable marker for disease loci mapped to the Xp11 region.
Kirchgessner
C U
CU
Department of Neurology, University of Massachusetts Medical School, Worcester 01655.
Trofatter
J A
JA
Mahtani
M M
MM
Willard
H F
HF
DeGennaro
L J
LJ
D000595:Amino Acid Sequence; D002871:Chromosome Banding; D002874:Chromosome Mapping; D005784:Gene Amplification; D008040:Genetic Linkage; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid; D016704:Synapsins; D014960:X Chromosome / Q000737:chemistry*
D009419:Nerve Tissue Proteins; D016704:Synapsins