Phylloid Hypomelanosis Research Articles

A CASE SERIES OF PHYLLOID HYPOMELANOSIS

THE PHYLLOID HYPOMELANOSIS is a defined as a distinct syndrome consisting of achromic phylloid skin lesions in combination with extracutaneous anomalies such as mental retardation , agenesis of corpus callosum , conductive hearing loss ,coloboma and various skeletal defects[1].

G29 A Case of Phylloid Hypomelanosis – a Rare But Specific Presentation of Chromosomal Mosaicism

This 18 month old boy presented with a history of hypopigmented macular lesions, mild neurodevelopmental delay and recurrent episodes of acrocyanosis with tachycardia and increased tone. The cutaneous lesions developed...

Phylloid Hypermelanosis: A Cutaneous Marker of Several Different Disorders?

Phylloid hypermelanosis is a less clearly defined pigmentary disturbance than its hypopigmented counterpart, phylloid hypomelanosis. We report the case of a 32-month-old boy who had multiple melanotic macules arranged in a typical phylloid pattern since birth. He also had an abnormal facial appearance, with macrocephaly, frontal bossing, hypertelorism, internal strabismus, and auricular deformities. Psychomotor delay, multiple cystic brain lesions, and bilateral sensorineural hearing loss were also found. A review of associated anomalies as described in this and five previously reported patients with phylloid hypermelanosis shows some vague and inconsistent similarities, such as unusual facial appearance, malformed ears, hearing loss, and mental deficiency, but it is likely that phylloid hypermelanosis represents a class of heterogeneous phenotypes. Future clinical and genetic research may show how many distinct entities can be placed in this group of disorders.

Phylloid Hypermelanosis in a Child with Psychomotor Delay, Cicatricial Alopecia, Hearing Loss and Polythelia

Phylloid hypermelanosis is a rare form of pigmentary mosaicism that has been reported only a few times in the literature (1–6). While phylloid hypomelanosis is linked to trisomy 13, the cause of phylloid hypermelanosis is more obscure (5, 7–13). We describe here a case of phyl-loid hypermelanosis associated with mild developmental delay, cicatricial alopecia, hearing loss and polythelia. CASE REPORT

Naevus Lentiginosus Linearis: A Distinct Skin Disorder

© 2010 The Authors. doi: 10.2340/00015555-0810 Journal Compilation © 2010 Acta Dermato-Venereologica. ISSN 0001-5555 Sir, Congenital naevi of the melanocytic system include numerous types, which differ in their clinical appearance, pattern of distribution, and histopathological features (1). Examples are large congenital melanocytic naevus, macular naevus spilus, papular naevus spilus, cafe-aulait macules of neurofibromatosis 1, cafe-au-lait macules arranged in broad bands as noted in McCune-Albright syndrome, partial unilateral lentiginosis, naevus achromicus (naevus depigmentosus), phylloid hypermelanosis, and phylloid hypomelanosis (1–3). We describe here two patients with a systematized pigmentary naevus that differed from all naevi reported so far.

Phylloid Hypomelanosis and Mosaic Partial Trisomy 13

Phylloid hypomelanosis is a rare neurocutaneous syndrome characterized by a pattern of hypopigmentation consisting of leaflike or oblong macules reminiscent of floral ornaments. Associated extracutaneous anomalies include cerebral, ocular, and skeletal defects. Recently it has been suggested that this phenotype originates from mosaic partial or complete trisomy 13. We report clinical and cytogenetic data for 2 cases. A bizarre pattern of multiple leaflike macules was noted in 2 girls with mental deficiency. In patient 1, additional anomalies included syndactyly, clinodactyly, trichomegaly of the eyelashes, low frontal hairline, and several pale pink telangiectatic macules. In patient 2, epileptic seizures, dental malposition, oligodontia, preauricular fistulas, scoliosis, tethered cord, and syringomyelia were noted. A diagnosis of phylloid hypomelanosis was made in both patients. In both patients, blood lymphocytes showed a normal karyotype 46,XX; however, fibroblasts derived from lesional skin demonstrated tetrasomy of chromosome 13q21-qter in patient 1 and trisomy of 13q22-qter in patient 2. These 2 cases lend further support to the concept that phylloid hypomelanosis is a distinct clinicogenetic entity that should no longer be confused with pigmentary mosaicism of the Ito type. From a comparison of our cytogenetic findings with those documented in previous articles, we infer that phylloid hypomelanosis is most likely related to the 13q region.

Tetrasomy 13q mosaicism associated with phylloid hypomelanosis and precocious puberty

Various forms of pigmentary dysplasias have been known to be associated with chromosomal mosaicism. One of these disorders, known as phylloid hypomelanosis, has been found to be predominantly associated with abnormalities in chromosome 13. Most of the reported literature involves mosaic trisomy 13 with clinical evidence of abnormal pigmentation in the form of leaf-like or oblong achromic macules following Blaschko's lines. Here, we report on an 8-year-old girl with phylloid hypomelanosis and precocious puberty who was found to have mosaicism for tetrasomy 13q in the form of inverted dup(13)(q21) on her skin fibroblasts as well as peripheral blood karyotype. A higher resolution (244K) chromosomal microarray was done on DNA from skin fibroblasts confirming the breakpoint and gain of distal 13q, which made her tetrasomic for 13q21-qter. This is the first-ever reported association of tetrasomy 13q with phylloid hypomelanosis and precocious puberty. Our report further emphasizes the need to exclude any type of abnormalities of chromosome 13 in patients with phylloid hypopigmentation.

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Dohi Memorial Lecture. New aspects of cutaneous mosaicism.

The concept of cutaneous mosaicism has today been proven at the cellular level in at least fifteen different skin disorders. We can distinguish five different patterns of mosaicism, including the phylloid pattern and the lateralization pattern. Etiologically, cutaneous mosaics can be divided into two large categories, epigenetic mosaicism and genomic mosaicism. All forms of epigenetic mosaicism known so far, including the various patterns of X-inactivation, appear to be caused by the action of retrotransposons. A new concept is functional autosomal mosaicism transmittable through the action of retrotransposons, which has been described in mice and dogs and may explain, for example, the familial occurrence of pigmentary mosaicism along the Blaschko lines in human skin. Among the examples of mosaicism of autosomal lethal mutations, phylloid hypomelanosis is a recently recognized neurocutaneous entity caused by mosaic trisomy 13. Possible examples of a type 2 segmental manifestation now include at least fifteen different autosomally dominant skin disorders. This phenomenon is most frequently found in glomangiomatosis, cutaneous leiomyomatosis, and disseminated superficial actinic porokeratosis. Recently proposed examples of didymosis (twin spotting) include cutis tricolor, paired patches of excessive or absent involvement in Darier disease, and didymosis aplasticosebacea characterized by coexistent aplasia cutis congenita and nevus sebaceus. To the list of possible examples of paradominant inheritance, cutis marmorata telangiectatica congenita and speckled lentiginous nevus syndrome have now been added. Revertant mosaicism giving rise to unaffected skin areas in autosomally recessive cutaneous traits will certainly likewise be recognized more often when clinicians are bearing this concept in mind. Such cases can be taken as examples of "natural gene therapy".