Mapping of hereditary trichilemmal cyst(TRICY1)to chromosome 3p24-p21.2 and exclusion of β-CATENINandMLH1

Abstract

Trichilemmal cysts (also named pilar cyst) derived from the outer root sheath of the deeper parts of the hair follicle can segregate dominantly, and are caused by a yet unknown gene. In order to identify candidate genes for this trait we have ascertained a Danish family with 38 persons (11 affected), and carried out a genome wide scan with 580 DNA micro-satellite markers to identify the locus for a gene, which we termed TRICY1 (for trichilemmal cysts). We found tight linkage to D3S1277 (Z = 4.63; theta(M = F) = 0.00), with flanking markers D3S2432 (Z = 1.59; theta(M = F) = 0.08), and D3S3685 (Z = 2.69; theta(M = F) = 0.08) spanning 10.3 Mb on chromosome 3p24-p21.2. We sequenced two candidate genes previously reported in inherited hair defects, CTNNB1 and MLH1 but failed to detect mutations in exons and intron-exon bounders.

Trichilemmal cyst nevus: A new complex organoid epidermal nevus

“…Multiple nonsegmental trichilemmal cysts are inherited as an autosomal dominant trait, and the underlying gene TRICY1 has been mapped to chromosome 3p24-p21.2. 29 We could postulate that a pronounced linear manifestation of trichilemmal cysts may occur as a segmental type 2 involvement reflecting loss of the corresponding wild-type allele of TRICY1. 30 According to present knowledge, however, this concept appears too simplistic to explain nevus trichilemmocysticus because it cannot account for the various additional cutaneous features of this disorder, and because nonsegmental trichilemmal cysts have so far not been noted in affected individuals and their relatives.…”

Numerous Recurrent Trichilemmal Cysts of the Scalp

“…3 It is commonly accepted that if a premalignant lesion is detected early and properly treated, it may not progress to oral cancer. 1 Delays in proper diagnosis may have an impact on the prognosis for serious oral pathologies and negatively affect the patients' quality of life.…”

“…1 Delays in proper diagnosis may have an impact on the prognosis for serious oral pathologies and negatively affect the patients' quality of life. 3 Clinical tools may assist clinicians in visualizing suspected oral lesions that are not readily detectable during the conventional oral examination. 3 Epstein et al 2 evaluated lesions clinically suggestive of being premalignant with ViziLite and toluidine blue stain before biopsy.…”

“…3 Clinical tools may assist clinicians in visualizing suspected oral lesions that are not readily detectable during the conventional oral examination. 3 Epstein et al 2 evaluated lesions clinically suggestive of being premalignant with ViziLite and toluidine blue stain before biopsy. The results of their study indicate that chemiluminescent light improves the brightness and/or sharpness of oral lesions.…”

“…2Y8,18 A trichilemmal cyst is a keratinous or semisolid keratin-filled cyst, of which lining cells show trichilemmal keratinization and a wall resembling the external root sheath of the deeper parts of a hair follicle. 2,3,10,18,34 Historically, and even nowadays, this tumor is still commonly mistaken with epidermoid cyst by many clinicians, and they are all included under the same nomenclature as sebaceous cysts. 13,25 To make it clearer, these tumors were all originally called ''common wen'' or ''sebaceous cysts.''…”