Analysis Of Gene Mutations In A Family With Monilethrix

Objective: To investigate the gene mutation of type II human basic hair keratin in a pedigree with monilethrix and the correlation between the genotype and phenotype of monilethrix and accumulate information for further study on pathogenic mechanism of monilethrix.Methods: Light microscopy was used to observe the structure of hair shafts. All extrons of hHb1, hHb3 and hHb6 were amplified by polymerase chain reaction(PCR). Mutation screening of the PCR products was detected by direct sequencing analysis.Results: The hair shafts showed a regular periodicity of nodes and narrow internodes, like a pearl necknace. A missense mutation (E402K) was found in extron7 of hHb6. Unaffected relatives did not have the hHb6 mutation and this codon was found no alteration in the unrelated 100 individuals.Conclusion: The mutation of extron7 of hHb6 identified may be play a major role in the pathogenic mechanism of this pedigree with monilethrix. The point mutation of hHb6, E402K, may be the most frequent mutation point of Chinese Han population with monilethrix. Further information may be used in prenatal diagnosis.