The clinical and (dermato) pathological signifcance of neural crest cells. Blaschko lines and dermatoses. Neurocristopathies

In the course of their migration the neural crest cells reach all parts of the developing embryo. The frst wave of the derivatives of these cells the melanoblasts and melanocytes harbour in the epidermis and hair follicles during the dorsolateral migration. A number of signal molecules and proteases play an important role in the course of melanocyte migration through the extracellular matrix. The Mongolian spots appear as a consequence of the transient inhibition of melanocyte migration and in the case of fnal obstruction the Ota-, or. Ito nevuses. The Blaschko lines based on cutaneous mosaicism are of great diagnostic importance and on the ground of these lines the blaschkitises can appear under the exogenous factors. The blaschkolinear acquired infammatory skin eruption (BLAISE) is an acquired infammatory process. One of its variants is the lichen striatus and the other is the blaschkitis. The blaschkolinear dermatoses can appear usually as a nevoid disease. The pathological development of the neural crest cells can induce pathological processes in other tissues of the body as well, which may appear in the form of the so-called neurocristopathies including approximately ffty manifestations. The knowledge of the diferent pigmentation forms as well as the pathological symptoms of neurocristopathies is of great importance for the clinican from a diagnostic point of view.

Acne Syndromes and Mosaicism

Abnormal mosaicism is the coexistence of cells with at least two genotypes, by the time of birth, in an individual derived from a single zygote, which leads to a disease phenotype. Somatic mosaicism can be further categorized into segmental mosaicism and nonsegmental somatic mosaicism. Acne is a chronic illness characterized by inflammatory changes around and in the pilosebaceous units, commonly due to hormone- and inflammatory signaling-mediated factors. Several systemic disorders, such as congenital adrenal hyperplasia, polycystic ovarian syndrome, and seborrhoea-acne-hirsutism-androgenetic alopecia syndrome have classically been associated with acne. Autoinflammatory syndromes, including PAPA, PASH, PAPASH, PsAPASH, PsaPSASH, PASS, and SAPHO syndromes include acneiform lesions as a key manifestation. Mosaic germline mutations in the FGFR2 gene have been associated with Apert syndrome and nevus comedonicus, two illnesses that are accompanied by acneiform lesions. In this review, we summarize the concept of cutaneous mosaicism and elaborate on acne syndromes, as well as acneiform mosaicism.

Mosaic trisomy 8 detected by fibroblasts cultured of skin

Introduction: Mosaic trisomy 8 or "Warkany's Syndrome" is a chromosomopathy with an estimated prevalance of 1:25,000 to 1:50,000, whose clinical presentation has a wide phenotypic variability. Case Description: Patient aged 14 years old with antecedents of global retardation of development, moderate cognitive deficit and hypothyroidism of possible congenital origin. Clinical Findings: Physical examination revealed palpebral ptosis, small corneas and corectopia, hypoplasia of the upper maxilla and prognathism, dental crowding, high-arched palate, anomalies of the extremities such as digitalization of the thumbs, clinodactyly and bilateral shortening of the fifth finger, shortening of the right femur, columnar deviation and linear brown blotches that followed Blaschko's lines. Cerebral nuclear magnetic resonance revealed type 1 Chiari's malformation and ventriculomegaly. Although the karyotype was normal in peripheral blood (46,XY), based on the finding of cutaneous mosaicism the lesions were biopsied and cytogenetic analysis demonstrated mosaic trisomy 8: mos 47,XY,+8[7]/46,XY[93]. Clinical Relevance: Trisomy 8 is clinically presented as a mosaic, universal cases being unfailingly lethal. In this particular case, cutaneous lesions identified the mosaic in tissue, although the karyotype was normal in peripheral blood. The cutaneous mosaicism represented by brown linear blotches which follow Blaschko's lines is a clinical finding that has not previously been described in Warkany's syndrome.