- Incontinentia pigmenti
- A genetic disease that begins soon after birth with the development of blisters on the trunk and limbs. These blisters then heal, but leave dark hyperpigmented streaks and marble-like whorls on the skin. Other key features include dental and nail abnormalities, bald patches and, in about one-third of cases, mental retardation. Incontinentia pigmenti (IP) is inherited as an X-linked dominant trait. The gene for IP is called IKBKG. A girl with IP has inherited the IKBKG mutation from a parent or has a new IKBKG mutation. IP is lethal in most, but not all, males. Mothers with IP have an equal chance of having a normal son, a normal daughter, and an IP daughter. Females with IP have nonrandom X-chromosome inactivation. Normally, one X chromosome in each cell of a female is randomly inactivated. In females with certain X-linked conditions, including IP, the X chromosome with the mutant allele is preferentially inactivated. This phenomenon is termed non-random (or skewed) X-chromosome inactivation. IP is also known as Bloch-Sulzberger syndrome.
* * *an X-linked dominant syndrome, usually lethal in utero to males, caused by mutation in the IKBKG gene (locus: Xq28), resulting in a mosaic pattern in which cells expressing the mutant chromosome die and are replaced by cells expressing the normal chromosome. In surviving infants, onset is at birth or shortly thereafter and proceeds through four phases, which may overlap. The first is characterized by erythematous linear streaks and vesiculation; in the second phase, the vesicles become dry and hyperkeratotic and form verrucous plaques. The third phase is characterized by hyperpigmented cutaneous lesions such as brown or gray-brown bands, whorls, swirls, or splatterlike patterns, which generally disappear by age 20. The fourth phase is marked by the appearance of hairless, anhidrotic, hypopigmented patches or streaks. It is often associated with developmental anomalies involving other structures such as the hair, eyes, skeletal system, and central nervous system. Called also Bloch-Sulzberger i. pigmenti and Bloch-Sulzberger syndrome.
Whorled pattern of vesicles in incontinentia pigmenti.
Medical dictionary. 2011.