Incontinentia pigmenti inherited from a father with a low level atypical IKBKG deletion mosaicism: a case report

Background Incontinentia pigmenti (IP) is an X-liked dominant genodermatosis caused by mutations of the IKBKG/NEMO gene. IP is mostly lethal in males in utero, and only very rare male cases with a somatic mosaic mutation or a 47,XXY karyotype have been reported. Case presentation We here report a case of an IKBKG gene deletion in a female infant presenting with a few blisters and erythema in her upper arms at birth. MLPA analysis revealed a rare 94 kb deletion in this patient, encompassing the IKBKG gene and IKBKGP pseudogene. PCR analysis indicated the presence of Alu elements at both ends of the deletion, suggesting non-allelic homologous recombination as an underlying mechanism. Notably, a low-level mosaic deletion was identified in her father's peripheral blood leukocytes by PCR, suggesting a rare father-to-daughter transmission of IP. Conclusion In family studies for an apparently sporadic IP case, parental analysis that includes the father is recommended due to the possibility of male mosaicism.

Automated summary

Incontinentia pigmenti (IP) is a skin disorder caused by mutations of the IKBKG/NEMO gene, which is mostly lethal in males in utero. A rare case of a female infant with an IKBKG gene deletion was reported, and a low-level mosaic deletion was also identified in the father's peripheral blood, indicating a rare mode of father-to-daughter transmission of IP.