Keratinocyte cytogenetics in 10 patients with pigmentary mosaicism: identification of one case of trisomy 20 mosaicism confined to keratinocytes

Abstract

In patients with clinically suspected PM but normal blood cytogenetics, keratinocytes may be more sensitive than skin fibroblasts in identifying cytogenetic mosaicism in selected patients. However, the additional diagnostic yield appears to be insufficient to justify routine keratinocyte cytogenetic investigation. Our findings indirectly support the hypothesis that Blaschko's lines delineate the embryonal migration paths taken by ectodermal cells including keratinocytes and melanocytes.

“Mosaic trachea” in a child with trisomy 9 mosaicism

“…Studies of large populations of patients with idiopathic mental retardation and normal karyotype by conventional testing have found chromosome abnormalities in up to 17% of cases when genome-wide microarray platforms are used [12]. More graphic examples of human tissue mosaicism can be found in two disorders of cutaneous pigmentation: hypomelanosis of Ito and linear and whorled hypermelanosis [13]. The pigmentary patterns in these disorders follow Blaschko's lines which are believed to trace the migration of embryonic cells.…”

Pigmentary mosaicism with left hemihypertrophy and syndactyly: Case report with review of literature

“…Some studies have demonstrated cytogenetic abnormalities in keratinocyte and melanocytes cultures. [12] Management of pigment mosaicism is multidisciplinary and mainly depends on the underlying systemic abnormalities.…”

Pigmentary mosaicism with trisomy 7

“…Such discordance between karyotypes of blood and skin is rare but has been reported. 4 Skin pigmentation is closely related to epidermal-dermal interaction. Although pigmentation is primarily related to the melanocytes, the surrounding keratinocytes and extracellular matrix proteins and fibroblasts in the underlying dermal compartments actively contribute to cutaneous homeostasis.…”