Linear and whorled nevoid hypermelanosis with bilateral giant cerebral aneurysms

A large X-chromosomal deletion is associated with microphthalmia with linear skin defects (MLS) and amelogenesis imperfecta (XAI)

A female patient is described with clinical symptoms of both microphthalmia with linear skin defects (MLS or MIDAS) and dental enamel defects, having an appearance compatible with X-linked amelogenesis imperfecta (XAI). Genomic DNA was purified from the patient's blood and semiquantitative multiplex PCR revealed a deletion encompassing the amelogenin gene (AMELX). Because MLS is also localized to Xp22, genomic DNA was subjected to array comparative genomic hybridization, and a large heterozygous deletion was identified. Histopathology of one primary and one permanent molar tooth showed abnormalities in the dental enamel layer, and a third tooth had unusually high microhardness measurements, possibly due to its ultrastructural anomalies as seen by scanning electron microscopy. This is the first report of a patient with both of these rare conditions, and the first description of the phenotype resulting from a deletion encompassing the entire AMELX gene. More than 50 additional genes were monosomic in this patient.

Linear and whorled nevoid hypermelanosis complicated with inflammatory linear verrucous epidermal nevus and ichthyosis vulgaris

We report a 17-year-old girl who presented with linear and whorled melanosis following Blaschko lines mainly on her trunk. Ichthyosiform lesions and linear scaling erythemas were observed respectively on her lower limbs and the dorsa of her hands, left knee, ankle and foot. No abnormality was found in systemic examination and blood tests. A biopsy specimen of pigmentation of her back showed there was increased pigmentation within the basal keratinocytes, with focal incontinentia pigmenti. Notable lymphangiectasis could also be seen in the mid part of dermis, which had never previously been described. The biopsy of scaling erythemas of her hand showed dominant hyperkeratosis with focal parakeratosis, acanthosis and papillomatous hyperplasia in the epidermis. The diagnosis of linear and whorled nevoid hypermelanosis (LWNH) complicated with inflammatory linear verrucous epidermal nevus and ichthyosis vulgaris was made in accordance with clinical and pathological manifestations. LWNH ought to be differentiated from incontinentia pigmenti and hypomelanosis of Ito.

Pigmentary disorders in the Mediterranean area

The Mediterranean area represents the area of land that borders the Mediterranean basin. It is composed of several countries that share many geographic and racial characteristics. Although Mediterraneans seem to share common skin type and are subjected to similar enviromental factors, they still represent a genetic and socioeconomic diversity. True prevalence of pigmentary disorders in this area depends on large epidemiologic studies, including countries that are not available. This article, however, highlights and classifies the most important developmental (heritable-genetic) and acquired pigmentary disorders seen and reported in this important area of the world.

Linear and whorled hypermelanosis

Linear and whorled nevoid hypermelanosis is a sporadic pigmentary anomaly occurring within the first weeks of life, characterized clinically by swirls and streaks of macular hyperpigmentation following the lines of Blaschko. Histologically it shows only epidermal melanosis. Underlying chromosomal mosaicism has been demonstrated in only a few published cases. Progressive cribriform and zosteriform hyperpigmentation is considered to be the localized variant of linear and whorled nevoid hypermelanosis. We report a retrospective study on 16 children referred consecutively over a 10-year period for evaluation of segmental, linear or swirled hyperpigmentation distributed along the lines of Blashko, consistent with a diagnosis of linear and whorled nevoid hypermelanosis. Associated abnormalities were found only in one out of six patients with the diffuse form (linear and whorled nevoid hypermelanosis-type) and in none of the remaining 10 children presenting the unilateral form (progressive cribriform and zosteriform hyperpigmentation-type). A long-term follow-up did not disclose further abnormalities. The authors discuss the nosologic position of this entity with respect to hypomelanosis of Ito. Linear and whorled nevoid hypermelanosis and hypomelanosis of Ito should be not considered single entities, but be rather grouped as a heterogeneous collection of nonspecific pigmentary disorders caused by genetic mosaicism. Skin findings in these diseases can differ according to the pigmentation in the normal cell line and whether the second line contains more or less melanosomes than the normal skin of the individual exhibiting mosaicism.

The clinical profile of children in India with pigmentary anomalies along the lines of Blaschko and central nervous system manifestations

The aim of this study was to describe the clinical profile of children with congenital pigmentary anomalies along Blaschko lines and the associated manifestations in the central nervous system. Twenty-six children aged 12 years or less (14 boys and 12 girls), with hypopigmentation and hyperpigmentation along Blaschko lines and central nervous system manifestations were included during the period June 2001 to December 2003. Detailed physical, cutaneous, and systemic examinations were carried out. Relevant investigations included histopathology, karyotyping, electroencephalogram, computerized tomography scans, and magnetic resonance imaging of the brain whenever possible. Twenty children had hyperpigmentation along the lines of Blaschko, four had hypopigmentation, and two had a combination of the two. Eight children had diffuse involvement. Of these, two each had hypomelanosis of Ito, incontinentia pigmenti and linear and whorled nevoid hypermelanosis. The remaining 20 patients could not be categorized as any of the described entities. The majority (92.3%) of patients manifested skin and central nervous system disorders before the age of 2 years. Hyperpigmentation along Blaschko lines was significantly higher in patients with central nervous system manifestations (p = 0.01). Developmental delay was the most frequent central nervous system presentation. Multiple systems were affected, including the eyes. Histology was useful to distinguish incontinentia pigmenti from other types of nevoid hyperpigmentation.