Incontinentia pigmenti is an X-linked dominant disorder characterized by distinct skin lesions and involving other ectodermal tissues such as teeth, hair, nails, eyes, and the central nervous system. The most common identifiable abnormalities are the cutaneous lesions, which are described in 4 stages. Neurologic abnormalities are the most common morbidity of this disorder. The IKBKG (inhibitor of kappa B kinase gamma), previously named NEMO, gene located in the short arm of chromosome X is linked with this disorder. The Incontinentia Pigmenti Genetic Biobank project has established a large collection deposit of biological samples, providing clinical information to facilitate research.
| || |
• Cutaneous manifestations are diagnostic, and there are 4 overlapping and variable stages: vesicular, verrucous, hyperpigmented, and atrophic.
| || |
• Genetic inheritance is X-linked dominant, linked to the IKBKG gene.
| || |
• CNS manifestations are common and can include seizures, microcephaly, mental retardation, spasticity, delayed motor development, and ataxia.
| || |
• Patients with incontinentia pigmenti should have ongoing neurologic, ophthalmologic, and dental follow-ups.
Historical note and terminology
The term "incontinentia pigmenti” is a description of the characteristic leakage or "incontinence" of melanin, which appears outside melanocytes in the superficial dermis and basal layer of epidermis. This was first described by Garrod in 1906 but more clearly defined by Bardach in 1925, Block in 1926, Sulzberger in 1928, and Siemens in 1929 (47). However, it was Haber in 1952 who first described the multiphasic and multisystemic nature of this disorder and proposed Bloch-Sulzberger syndrome as its eponym. In 1959 Oldfelt believed this condition to be misnamed because there is no “incontinence of pigmentation,” but rather pigmentation occurring secondary to scarring in the ectoderm (68). He described incontinentia pigmenti as an “ecto-meso-dermal polydysplastic disease” and noted that it “mostly affects the female sex.” In 1961, Lenz first proposed the mode of inheritance of this disorder as X-linked dominant inheritance (50).