Objective: To map and eventually identify the gene responsible for Smith-Fineman-Myers syndrome.
Methods: The short tandem repeat markers(STRs) distributed on X chromosome at 8-10cM interval were used in the initial mapping to look for the candidate region for Smith-Fineman-Myers syndrome locus and the linked marker. The additional STRs flanking the linked marker were tested to confirm the candidate region and decide the interval of disease gene.
Results: Thirteen DNA samples from a Chinese family with Smith-Fineman-Myers syndrome were genotyped using 20 polymorphic STRs which cover the whole X chromosome. Of 20 STRs, DXS1001 on Xq25 suggested linkage and yielded a lod score of 3.01 at straight theta = 0 additional STRs flanking DXS1001 were tested. Fourteen polymorphic STRs out of 27 confirmed that Smith-Fineman-Myers syndrome locus is linked to several markers on Xq25. Haplotype analysis placed the disease locus within a 14.6cM interval bounded by DXS8064 and DXS8050.
Conclusion: The gene responsible for Smith-Fineman-Myers syndrome is mapped to a 14.6cM interval between DXS8064 and DXS8050 on Xq25. This result will be helpful for the identification of disease gene.