Investigation Of The Polymorphism Of The Type II Hair Keratin Genes In A HAN Family Of Congenital Monilethrix

Objective: To investigate the polymorphism of type II human basic hair keratin (hHb/KRTHB) gene in a HAN family of congenital monilethrix and accumulate information for further study on pathogenic mechanism of monilethrix.Methods: Informed consent for the study was obtained from the proband and her family members. Their peripheral blood samples were drawn for their genomic DNA. Exon 1 and exon 7 of hHb1, hHb3 and hHb6 were amplified by polymerase chain reaction (PCR). All PCR products were sequenced directly using ABI3730 automated sequencer. These sequences were compared with sequences in GenBank with BLAST software. At last, digestion with restriction endonuclease and restriction fragment length polymorphism (RFLP) was used to confirm a novel single nucleotide polymorphisms(SNPs).Results: A series of specific PCR products were gained from all specimens. The 10 missense mutations in hHb which had been reported were not identified in our study pedigree. A SNPs (348 G/A, R116R) was identified in exon 1 of hHb1 gene from this family members. It is a novel coding SNPs (cSNPs) confirmed with restriction endonuclease and RFLP.Conclusion: There might be a pathogenic gene in our study family, which is different from the 10 reported pathogenic mutations in hHb gene; there is a novel cSNPs identified in the exon 1 of hHb1 gene in this family.