Segmental Vitiligo and Somatic Mosaicism: From Pathogenesis to Therapeutics

Area of Science:

• Dermatology
• Developmental Biology
• Genetics

Background:

• Segmental vitiligo (SV) presents as unilateral depigmentation, differing from non-segmental vitiligo (NSV) in its clinical course and autoimmune association.
• SV is increasingly recognized as a mosaic disorder, originating from post-zygotic genetic or epigenetic alterations during embryogenesis.

Purpose of the Study:

• To explore the pathogenic mechanisms and developmental origins of segmental vitiligo.
• To highlight the clinical implications of understanding SV as a mosaic disorder.

Main Methods:

• Review of clinical, epidemiological, and mechanistic evidence.
• Analysis of embryologic studies on melanoblast migration and proliferation.
• Consideration of potential neurocutaneous involvement.

Main Results:

• Evidence supports SV arising from somatic mosaicism, leading to clonally distinct melanocyte populations.
• The segmental distribution aligns with embryonic patterning, such as Blaschko's lines.
• Potential for broader neurocutaneous mosaicism exists, though its primary nature is debated.

Conclusions:

• Segmental vitiligo is best understood as a mosaic disorder with implications for patient management.
• Future research requires multi-omics approaches and long-term registries for precision management.