Segmental Pigmentation Disorder: Clinical Manifestations and Epidemiological Features in 144 patients, a Retrospective Case-control Study.

Segmental pigmentation disorder (SPD) is characterized by hypo- or hyper-pigmented patches segmentally distributed, present in infancy, more prominently in darker-skinned children. The aim of this study was to define the demographic and clinical characteristics of SPD in a large series of patients. This was a retrospective case-control study at 2 paediatric dermatology centres in Israel. Data were collected through a telephone questionnaire and medical records. The study group consisted of 144 individuals with SPD and 144 individuals visiting the same institutions matched for age and sex. Median age of onset of SPD was near birth; 51% of patients were Sephardic Jews, and patients were followed up for a median period of 27 years. The patches were located on the torso (43%), mostly hypopigmented (52%), and remained of the same intensity and size in 55% and 41% of cases, accordingly. No differences in extracutaneous morbidities were found between SPD and control patients. This study delineates the demographic and clinical characteristics of SPD, confirms that cutaneous findings in SPD are more prominent in darker skin, tends not to expand in size or accentuate throughout the years, nor to be associated with extracutaneous morbidities.

Pediatric cutaneous mastocytosis: a review of 180 patients.

BACKGROUND: Mastocytosis is a heterogeneous group of diseases characterized by the abnormal infiltration of mast cells in the skin and, sometimes, other organs. Some patients may experience symptoms related to mast cell mediator release. OBJECTIVE: To analyze the clinical features of cutaneous mastocytosis in a large series of children. METHODS: We conducted a file review of all children clinically diagnosed with cutaneous mastocytosis in our department over the last 20 years. We evaluated gender, age at onset, character and distribution of the lesions, associated symptoms, and course of the disease. RESULTS: Altogether, 180 patients with cutaneous mastocytosis were identified. The male to female ratio was 1.5:1. About one-third of patients had a mastocytoma, which was present at birth in over 40% and appeared during the first year of life in most of the remainder. Urticaria pigmentosa was noted in 65% of the patients, presenting at birth in 20% and during the first year in most of the remainder. The majority of lesions was distributed over the trunk and limbs. Different kinds of associated symptoms were noted. Prognosis in general was good. Only 11% of the cases, all urticaria pigmentosa, were familial. CONCLUSIONS: Most cases of pediatric mastocytosis are sporadic and appear during the first 2 years of life, especially on the trunk. Urticaria pigmentosa is the most frequent variant. The prognosis of pediatric mastocytosis, in general, is good.

A deleterious mutation in SAMD9 causes normophosphatemic familial tumoral calcinosis.

Familial tumoral calcinosis (FTC) is a rare autosomal recessive disorder characterized by the progressive deposition of calcified masses in cutaneous and subcutaneous tissues, which results in painful ulcerative lesions and severe skin and bone infections. Two major types of FTC have been recognized: hyperphosphatemic FTC (HFTC) and normophosphatemic FTC (NFTC). HFTC was recently shown to result from mutations in two different genes: GALNT3, which codes for a glycosyltransferase, and FGF23, which codes for a potent phosphaturic protein. To determine the molecular cause of NFTC, we performed homozygosity mapping in five affected families of Jewish Yemenite origin and mapped NFTC to 7q21-7q21.3. Mutation analysis revealed a homozygous mutation in the SAMD9 gene (K1495E), which was found to segregate with the disease in all families and to interfere with the protein expression. Our data suggest that SAMD9 is involved in the regulation of extraosseous calcification, a process of considerable importance in a wide range of diseases as common as atherosclerosis and autoimmune disorders.