Other
Epidemiology
- Rare
Pathogenesis
- Mosaic mutations in various genes depending on clinical phenotype involving keratins, RAS and AKT pathway, FGFRs, etc.
Clinical features
- Clinical presentation resembles that of the original disease, but follows the lines of Blashko. The chance of extracutaneous disease is higher when extensive skin lesions are seen (earlier mutation).
Diagnosis/pathology
- Pathology is variable
Epidemiology
- Rare
Pathogenesis
- Multiple underlying mosaic mutations, often same mutations as above but more severe phenotypes.
Clinical features
- Overgrowth syndromes:
- Proteus (AKT1 gene)
- SOLAMEN (type 2 mosaicism)
- CLOVE (PIK3CA)
- Neavus sebaeceous syndrome (Schimmelpenning) (HRAS)
- Comedonal (FGFR2)
Pathogenesis
- NSDHL mutation: 3β-hydroxysteroid dehydrogenase (cholesterol biosynthesis)
- XLD enopamil binding protein (EBP) gene mutation
Clinical features
- Unilateral skeletal hypoplasia
- Unilaterally distributed erythematous, thickened skin and yellowish scale
Treatment:
- Topical lovastatin or simvastatin plus cholesterol
Pathogenesis
- HCCS mutation: mitochondrial holocytochrome c synthase (oxidative phosphorylation and apoptosis)
- XLD enopamil binding protein (EBP) gene mutation
Clinical features
- Microphthalmia, dermal aplasia, sclerocornea ± cardiac arrhythmias
Pathogenesis
- OFD1 (CXORF5) mutation: centrosomal protein at the base of primary (non-motile) cilia (signaling pathways)
- XLD enopamil binding protein (EBP) gene mutation
Clinical features
- Cleft (or pseudocleft) lip/palate, tongue lobulations/hamartomas, hypertrophic oral frenula, digital malformations, CNS abnormalities, facial milia, patchy alopecia
Pathogenesis
- GNAS: increased signaling in pathways where cyclic AMP acts as a “second messenger”
Clinical features
- Increased pigmentation due to stimulation of tyrosinase
- Large blocks of café-au-lait + polyostotic fibrous dysplasia + endocrine hyperfunction (precocious puberty)