Incontinentia pigmenti in adults

Incontinentia Pigmenti (IP; MIM 308300) is an X-linked dominant genodermatosis caused by pathogenic variant in IKBKG. The phenotype in adults is poorly described compared to that in children. Questionnaire survey of 99 affected women showed an age at diagnosis from newborn to 41 years, with 53 diagnosed by 6 months of age and 30 as adults. Stage I, II, and III lesions persisted in 16%, 17%, and 71%, respectively, of those who had ever had them. IP is allelic to two forms of ectodermal dysplasia. Many survey respondents reported hypohidrosis and/or heat intolerance and most had Stage IV findings. This suggests that “Stage IV” may be congenitally dysplastic skin that becomes more noticeable with maturity. Fifty-one had dentures or implants with 26 having more invasive jaw or dental surgery. Half had wiry or uncombable hair. Seventy-three reported abnormal nails with 27 having long-term problems. Cataracts and retinal detachment were the reported causes of vision loss. Four had microphthalmia. Respondents without genetic confirmation of IP volunteered information suggesting more involved phenotype or possibly misassigned diagnosis. Ascertainment bias likely accounts for the low prevalence of neurocognitive problems in the respondents.