1/3. Familial gastrointestinal stromal tumor with hyperpigmentation: association with a germline mutation of the c-kit gene.We describe 2 siblings with multiple gastrointestinal stromal tumors (GISTs) and cutaneous hyperpigmentation. Both had a point mutation of the c-kit gene. The patients were sisters who had exhibited cutaneous hyperpigmentation since their late teens, but the diagnosis of multiple gastrointestinal submucosal tumors was not made until they were 41 and 45 years old. Histologic examination showed that these tumors were GISTs expressing CD34 and Kit protein. Both patients died of GISTs. Single-strand conformation polymorphism analysis showed a mutation of c-kit in tumor dna extracted from paraffin-embedded specimens. Direct sequencing analysis showed that the point mutation occurred at codon 559 of exon 11 (Val-->Ala). The same single-point mutation was detected in dna extracted from peripheral leukocytes obtained from the younger sister and her 2 children (who had similar general hyperpigmentation) as well as in dna from a skin biopsy specimen taken from the older sister. The germline mutation at codon 559 of the c-kit gene found in the present familial GISTs differed from that in a previously reported case of familial GISTs. We propose that GISTs caused by a germline mutation of the c-kit gene should be referred to as GIST-cutaneous hyperpigmentation disease.- - - - - - - - - - ranking = 1keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
2/3. Kindler syndrome.Kindler syndrome is a rare genodermatosis characterized by acral bullae and photosensitivity. The photosensitivity improves with advancing age and results in progressive poikiloderma and cutaneous atrophy, and many additional features have also been described. This report describes two male Kindler syndrome patients with classical features of acral blistering and photosensitivity in childhood, and subsequent development of poikiloderma, leukokeratosis of oro-ano-genital mucosae, phimosis and meatal stenosis. The first patient had additional ophthalmic features of chronic simple conjunctivitis caused by persistent irritation, multiple stromal nebular corneal opacities and thickened corneal nerves. The second patient showed skeletal changes, namely a dome-shaped skull (turri-cephaly), bifid fourth rib, missing fifth rib, short fourth and fifth metacarpals and mandibular abnormalities. This is the first report of such ophthalmic and skeletal features of Kindler syndrome.- - - - - - - - - - ranking = 0.0012478022507919keywords = stromal (Clic here for more details about this article) |
3/3. Novel c-KIT germline mutation in a family with gastrointestinal stromal tumors and cutaneous hyperpigmentation.Mutations in the c-KIT gene have been identified in many sporadic and familial cases of gastrointestinal stromal tumor (GIST). We report a familial case of GIST with cutaneous hyperpigmentation associated with a novel germline mutation in the c-KIT gene. Screening for mutations in exon 11 of the c-KIT gene in genomic dna from tumors and peripheral blood of the members of a family with GISTs was undertaken by direct genomic sequencing. Tumors from GIST patients were analyzed histologically and immunohistochemically. Clinical examination of GIST patients was also performed to detect other systemic diseases associated with c-KIT mutations. Histological study showed that the tumors were GISTs expressing CD34 and c-KIT protein. This GIST-hyperpigmentation disease was associated in the family with a germline mutation in the c-KIT gene. The mutation is a duplication of the sequence CAACTT located in exon 11 of the c-KIT gene, which introduces two extra glutamine and leucine residues in the encoding protein between positions 576 and 577. This Spanish family was affected with GISTs and cutaneous hyperpigmentation associated with a novel germline mutation Leu576_Pro577insGlnLeu in the juxtamembrane domain of the c-KIT receptor. These types of mutation in the c-KIT gene activate the tyrosine kinase activity of the c-KIT receptor and induce constitutive signaling leading to GISTs, in some cases associated with cutaneous hyperpigmentation.- - - - - - - - - - ranking = 1keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |