Fett Nicole M, Teng Joyce, Longley B Jack
Department of Dermatology, Philadelphia VA Medical Center, Philadelphia, PA, USA.
Am J Dermatopathol. 2013 Feb;35(1):113-6. doi: 10.1097/DAD.0b013e31826330bf.
Cutaneous mastocytosis is a rare clinically heterogeneous disorder characterized by mast cell infiltration. Mastocytosis affects both children and adults and has been reported to occur in families. Recent data suggest that mutations in the c-kit proto-oncogene are causative of mastocytosis not only in adults but in children and familial cases as well; however, mutation analysis other than D816V is not widely available, making detection of causative mutations problematic. We present the case of a 33-year-old man with a 30-year history of persistent urticaria pigmentosa and his 2 affected children. Sequencing of KIT exons 8, 10, 11, and 17 was carried out on a skin biopsy specimen and mucosal swabs of the incident case and was negative for known KIT mutations. Additional work-up was deferred by the family. Presentation of this familial case of urticaria pigmentosa demonstrates the complexity of genetic evaluation in clinical settings. It suggests that mutations other than those reported in exons 8, 10, 11, and 17 may also result in familial mastocytosis. Presentation of this case also allows for review of the mechanism of action of causative KIT mutations and the recent literature supporting KIT mutations in childhood and familial mastocytosis.
皮肤肥大细胞增多症是一种罕见的临床异质性疾病，其特征为肥大细胞浸润。肥大细胞增多症可累及儿童和成人，且有家族发病的报道。近期数据表明，c-kit原癌基因突变不仅是成人肥大细胞增多症的病因，在儿童和家族性病例中也是如此；然而，除D816V外的突变分析方法尚未广泛应用，导致致病突变的检测存在问题。我们报告一例33岁男性患者，有30年持久性色素性荨麻疹病史，以及他的2名患病子女。对该病例的皮肤活检标本和黏膜拭子进行了KIT基因第8、10、11和17外显子的测序，结果显示已知的KIT突变均为阴性。该家族推迟了进一步检查。这例家族性色素性荨麻疹病例的呈现展示了临床环境中基因评估的复杂性。这表明，除第8、10、11和17外显子中报道的突变外，其他突变也可能导致家族性肥大细胞增多症。展示该病例还可以回顾致病KIT突变的作用机制，以及支持儿童和家族性肥大细胞增多症中KIT突变的近期文献。
