6 research outputs found
Phenotypic and genotypic characteristics of mastocytosis according to the age of onset.
International audienceAdult's mastocytosis is usually associated with persistent systemic involvement and c-kit 816 mutation, while pediatrics disease is mostly limited to the skin and often resolves spontaneously. We prospectively included 142 adult patients with histologically proven mastocytosis. We compared phenotypic and genotypic features of adults patients whose disease started during childhood (Group 1, n = 28) with those of patients whose disease started at adult's age (Group 2, n = 114). Genotypic analysis was performed on skin biopsy by sequencing of c-kit exons 17 and 8 to 13. According to WHO classification, the percentage of systemic disease was similar (75 vs. 73%) in 2 groups. C-kit 816 mutation was found in 42% and 77% of patients in groups 1 and 2, respectively (p<0.001). 816 c-kit mutation was associated with systemic mastocytosis in group 2 (87% of patients with systemic mastocytosis vs. 45% with cutaneous mastocytosis, p = 0.0001). Other c-kit activating mutations were found in 23% of patients with mastocytosis' onset before the age of 5, 0% between 6 and 15 years and 2% at adults' age (p<0.001). In conclusion, pathogenesis of mastocytosis significantly differs according to the age of disease's onset. Our data may have major therapeutic relevance when considering c-kit-targeted therapy
Relationship between phenotype and genotype in patients with mastocytosis according to their age of onset.
<p>Data are expressed in number (percentage).</p
Exons 8 through 13 and 17 mutations according to mastocytosis age of onset.
<p>Data are expressed in number (percentage), 816: substitution of valine in 816 codon of <i>c-kit</i>, Other mutations: mutation in exons 8 through 13. WT: absence of mutation in exons 8 through 13 and 17. Complete genotype was not available for 4 816 WT patients; 1 patient in group 1A, 1 in group 1B and 2 in group 2.</p
Primer positions are indicated from the c-Kit sequence published through the NCBI accession number X06182.
<p>Primer positions are indicated from the c-Kit sequence published through the NCBI accession number X06182.</p
Description of 5 adult patients with mastocytosis not related to 816 c-kit mutation.
<p>Description of 5 adult patients with mastocytosis not related to 816 c-kit mutation.</p