Improved molecular diagnosis of the common recurrent intragenic deletion mutation in IKBKG in a Filipino family with incontinentia pigmenti.

Incontinentia pigmenti is a rare, multisystem X-linked dominant genetic disorder caused by mutations in IKBKG, the encoding inhibitor of kappa light polypeptide gene enhancer in B-cells. Almost 80% of all cases result from a recurrent intragenic deletion mutation that removes exon 4-10. At present, this mutation can be detected by a multi-primer polymerase chain reaction (PCR) technique although current protocols may preferentially amplify the wild-type allele and miss the deletion. Here, we report a female infant with incontinentia pigmenti that also affected her mother and sister, and two spontaneously aborted male siblings. We developed a modified PCR amplification method that provides more robust detection of the exon 4-10 deletion mutation, which was demonstrated in all affected females in this pedigree.