Abstract: 【Abstract】 Objective To identify gene mutations in a family with incontinentia pigmenti, in order to confirm pathogenic mutations. Methods Clinical data were collected from all patients in a family with incontinentia pigmenti. DNA was extracted from peripheral blood samples obtained from the patients, healthy members in the family, and 100 unrelated healthy controls, and Sanger sequencing was performed for all exons and their flanking sequences of the NEMO gene. Results Totally, there were 4 patients in the 4-generation family, who all presented with typical skin lesions and different symptoms. Genetic testing indicated that the proband and the other 3 patients all carried a heterozygous nonsense mutation c.1153C>T （p.Gln385X） at position 1153 in exon 8 of the NEMO gene, which led to the substitution of the glutamine codon （CAG） by the termination codon （TAG） at amino acid position 385. The mutation was not identified in the 14 healthy relatives or 100 unrelated healthy controls. The mutation cosegregated with incontinentia pigmenti in the family. Database searching confirmed the mutation to be a novel nonsense mutation, and it was considered as a very strong pathogenic locus according to the American College of Medical Genetic and Genomics guidelines. Conclusion The mutation c.1153C>T in the NEMO gene is associated with the occurrence of incontinentia pigmenti in this family.

Key words: Genetic testing, DNA mutational analysis, Incontinentia pigmenti, NEMO gene