[Gene mapping of developmental dysplasia of the hip in chromosome 17q21 region].

OBJECTIVE

To map the susceptibility gene of developmental dysplasia of the hip(DDH) in chromosome 17q21 region.

METHODS

According to the number of alleles (≥ 5), heterozygosity (≥ 0.70) and polymorphic information content (PIC≥ 0.5), 11 STR markers in the 17q21 region were chosen for transmission disequilibrium test (TDT). STR markers were amplified by PCR and genotypes were analyzed by capillary electrophoresis in 103 trio families. TDT was used to locate the susceptibility gene in 17q21 region.

RESULTS

Because of a low genetic polymorphism, D17S810 and D17S931 loci were removed from the TDT. Transmission disequilibrium was detected at D17S855, D17S858, D17S806, D17S1877, D17S941, D17S752 and D17S790, which overlapped 11.7 cM in 17q21. However, no transmission disequilibrium was found at D17S1787 and D17S787. Thus, the susceptibility gene for DDH was located in the chromosome region between D17S855 and D17S790.

CONCLUSION

The susceptibility gene for DDH is narrowed to an 11.7 cM region of 17q21.31-17q22, between STR loci D17S855 and D17S790.