Incontinentia pigmenti
Incontinentia pigmenti | |
---|---|
Other names | Bloch–Siemens syndrome, Bloch–Sulzberger disease, Bloch–Sulzberger syndrome, nelanoblastosis cutis, nevus pigmentosus systematicus X-linked dominant manner. |
Specialty | Medical genetics |
Incontinentia pigmenti (IP) is a rare
The disease is characterized by skin abnormalities that begin in childhood, usually a blistering rash which heals, followed by the development of harder skin growths. The skin may develop grey or brown patches which fade with time. Other symptoms can include hair loss, dental abnormalities, eye abnormalities that can lead to vision loss and lined or pitted fingernails and toenails. Associated problems can include delayed development, intellectual disability, seizures and other neurological problems. Most males with the disease do not survive to childbirth.
Incontinentia pigmenti is caused by a mutation in the
There is no specific treatment; individual conditions must be managed by specialists.[2]
Presentation
The
- blistering (from birth to about four months of age),
- a wart-like rash (for several months),
- swirling macular hyperpigmentation (from about six months of age into adulthood), followed by
- linear hypopigmentation.
The discolored skin is caused by excessive deposits of melanin (normal skin pigment). Most newborns with IP will develop discolored skin within the first two weeks. The pigmentation involves the trunk and extremities, is slate-grey, blue or brown, and is distributed in irregular marbled or wavy lines. The discoloration sometimes fades with age.[citation needed]
Neurological problems can include
Breast anomalies can occur in 1% of patients and can include hypoplasia or supernumerary nipples.
Skeletal and structural anomalies can occur in approximately 14% of patients, including:[citation needed]
- Somatic asymmetry
- Hemivertebrae
- Scoliosis
- Spina bifida
- Syndactyly
- congenitalabsence of the hands—note: other limbs may be affected)
- Ear anomalies
- Extra ribs
- Skull deformities
Genetics
IP is inherited in an X-linked dominant manner.
In females, the cells expressing the mutated IKBKG gene due to
IP is caused by mutations in a gene called NEMO (NF-κB essential modulator).[citation needed]
Diagnosis
The diagnosis of IP is established by clinical findings and occasionally by corroborative skin biopsy. Molecular genetic testing of the NEMO IKBKG gene (chromosomal locus Xq28) reveals disease-causing mutations in about 80% of probands. Such testing is available clinically. In addition, females with IP have skewed X-chromosome inactivation; testing for this can be used to support the diagnosis. Many people in the past were misdiagnosed with a second type of IP, formerly known as IP1. This has now been given its own name: 'Hypomelanosis of Ito' (incontinentia pigmenti achromians). This has a slightly different presentation: swirls or streaks of hypopigmentation and depigmentation. It is not inherited and does not involve skin stages 1 or 2. Some 33–50% of patients have multisystem involvement—eye, skeletal, and neurological abnormalities. Its chromosomal locus is at Xp11, rather than Xq28.[citation needed]
Treatment
There does not yet exist a specific treatment for IP. Treatment can only address the individual symptoms.[7]
History
This disorder was first reported by Swiss dermatologist Bruno Bloch in 1926 and American dermatologist Marion Sulzberger in 1928.[8][9][2]
See also
- List of cutaneous conditions
- List of radiographic findings associated with cutaneous conditions
- List of dental abnormalities associated with cutaneous conditions
References
- ^ ISBN 978-1-4160-2999-1.[page needed]
- ^ S2CID 40446256.
- S2CID 73197872.
- PMID 11098039.
- ^ "Incontinentia pigmenti. DermNet NZ".
- S2CID 186243924.
- ^ "Incontinentia pigmenti". Medline Plus. Retrieved 26 December 2017.
- Who Named It?
- ^ Bloch, B. (1926). "Eigentümliche, bisher nicht beschriebene Pigmentaffektion (incontinentia pigmenti)" [Peculiar, as yet unexplained pigment affection (incontinentia pigmenti)]. Schweizerische medizinische Wochenschrift (in German). 56. Basel: 404–5.