Mutation analysis of HOXD13 gene in a Chinese pedigree with synpolydactyly.

OBJECTIVE: To study the clinical features and to identify homeobox D13 (HOXD13) gene mutation of the affected individuals in a Chinese synpolydactyly (SPD) kindred. METHODS: Clinical data and peripheral blood samples of SPD family members were obtained through field investigation. For every member of this pedigreeìthe fragment containing mutational hot spots of HOXD13 was amplified by PCR for mutation screening. To examine whether there is any other mutation within coding sequence of HOXD13, exon 1 and exon 2 of HOXD13 were also amplified by PCR. All the amplified fragments were electrophoresed on 2% agarose gels and then the mutant fragments were electrophoresed on 5% polyacrylamide gels to be separated. Purified PCR products of normal and selected mutant alleles were directly sequenced. RESULTS: Comparing the HOXD13 coding sequence of the affected individuals with HOXD13 sequence in the GenBank and with that of the unaffected, an inserted segment coding 8 alanine residues within HOXD13 was found segregating with the disorder. This mutation is also termed polyalanine expansion. The 8-alanine expansion can be interpreted as a reduplication of normal alanines 5-12. CONCLUSION: The results suggest that synpolydactyly in this kindred may be caused by polyalanine expansion in HOXD13.

[A case-control study on the risk factor of perinatals' congenital malformations in seven cities of Guangxi].

OBJECTIVE: To investigate the possible risk factors of congenital malformations in cities of Guangxi. METHODS: A case-control study was carried out on 281 cases of congenital malformations and 730 controls. Analysis of simple factor and multiple factors unconditional logistic regression were done. RESULTS: The analysis of simple factor and multiple factors showed that main risk factors of congenital malformations as multiple pregnancies (OR = 2.6), pregnancy complications (OR = 3.2), exposure to chemical substances before or during pregnancy (OR = 3.0), taking sedatives (OR = 10.2), hormone drug (OR = 9.4) or Chinese herbal medicines (OR = 2.5) during the early stage of pregnancy, mothers' blood type as AB (OR = 3.5) or A (OR = 2.2), mothers' emotion being nervous and melancholy (OR = 2.6), mothers' occupation being workers (OR = 3.8) or peasants (OR = 3.0), fathers' exposure to noise (OR = 5.7) or suffering from chronic diseases (OR = 2.8). CONCLUSIONS: Some risk factors were identified as having important effect on perinatal congenital malformations, including taking sedatives, hormone drug or Chinese herbal medicines during the early stage of pregnancy, mothers' emotion being nervous and melancholy, multiple pregnancies, pregnancy complications, exposure to chemical substances before or during pregnancies, mothers' blood type as AB or A, mothers' occupation being workers or peasants, fathers' exposure to noise or suffering from chronic diseases.