The principal result expected is the discovery of inframicroscopic chromosomal rearrangements in regions of the genome not yet known to be involved, or mutations in known candidate genes;

The identification of such a mosaic rearrangement in an affected infant would lead to improved genetic counselling. Indeed, as this mosaicism is a consequence of a genetic event occurring at an early stage of embryogenesis, it would be possible to confirm the sporadic nature of the observed disorder and therefore to predict a very low or even negligible risk of recurrence for the couple concerned. For the affected infant, the risk for his/her own offspring will be assessed according to the nature of the genetic anomaly discovered. For medical practice, investigators hope that this study will lead to a clearer definition of the screening modalities for mosaicism in the disorders concerned. In particular, they hope to determine whether or not it is possible to dispense with a skin biopsy, which is more invasive than a blood sample.

Inclusion Criteria:

• Persons who have provided written informed consent
• Lower age limit: infant born at more than 37 WA
• Sporadic disorder
• Patients presenting at least two skin criteria, or one skin criterion and one non-skin criterion
• Skin criteria: 1- extensive epidermal or sebaceous naevus, 2- Extensive "segmental" haemangioma, 3- Flat angioma or extensive complex vascular malformation, 4-Pigmentary disorders with patterns suggesting mosaicism (Blaschko lines)
• Non-skin criteria: Cerebral, ocular, cardiac or genito-urinary malformation, asymmetric body, segmental hypertrophy of a limb, spinal dysraphism (only when associated with haemangioma)

Exclusion Criteria:

• Persons not covered by the national health insurance scheme
• Mendelian disorders: CM-AVM syndrome, glomangiomatosis, Cowden or Bannayan syndrome, type 1 neurofibromatosis, incontinentia pigmenti, CHILD syndrome, Happle-type chondrodysplasia punctata
• Mendelian mosaic disorders: epidermal or epidermolytic, comedo or dyskeratotic nevus.
• Family history of one of these disorders
• Suspicion or an autosomal dominant disease
• Patient and/or parent under guardianship or ward of court