Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that affects the skin, hair, teeth, nails and central nervous system.

Incontinentia pigmenti is caused by a mutation in the IKBKG gene, which encodes the NEMO protein, which serves to protect cells against TNF-alpha-induced apoptosis.

[2] The skin lesions evolve through characteristic stages:[citation needed] Alopecia, dental anomalies, and dystrophic nails are observed.

The pigmentation involves the trunk and extremities, is slate-grey, blue or brown, and is distributed in irregular marbled or wavy lines.

[citation needed] Neurological problems can include cerebral atrophy, the formation of small cavities in the central white matter of the brain, and the loss of neurons in the cerebellar cortex.

About 20% of children with IP will have slow motor development, muscle weakness in one or both sides of the body, intellectual disability, and seizures.

Skeletal and structural anomalies can occur in approximately 14% of patients, including:[citation needed] IP is inherited in an X-linked dominant manner.

[citation needed] In females, the cells expressing the mutated IKBKG gene due to lyonization selectively die around the time of birth, so the X-inactivation is extremely skewed.

Molecular genetic testing of the NEMO IKBKG gene (chromosomal locus Xq28) reveals disease-causing mutations in about 80% of probands.