Clinical manifestations of Jacobsen syndrome (JBS) depend on the size of the 11qter deletion, which usually varies between approximately 7 and 20 Mb. Typical JBS features include developmental delay/mental retardation, short stature, congenital heart defects, thrombocytopenia, and characteristic dysmorphic facial features. We report on a family in which a 4-year-old girl as well as her mother and maternal uncle present with subtle features of JBS. Notably, neither thrombocytopenia nor congenital anomalies were detected in this family. Cytogenetic analyses revealed normal karyotypes. Using fluorescence in situ hybridization (FISH) and whole-genome oligonucleotide array CGH analyses, we identified an approximately 5 Mb deletion of the terminal part of chromosome 11q in all the three affected family members. The deletion breakpoint was mapped between 129,511,419 and 129,519,794 bp. This is the smallest deletion reported in a JBS patient. Interestingly, the FLI1 (friend leukemia virus integration 1) hematopoiesis factor gene located approximately 6.5 Mb from 11qter and usually deleted in patients with JBS, is intact. Our data support previous hypotheses that FLI1 haploinsufficiency is responsible for thrombocytopenia in patients with JBS.

Basal cell carcinoma (BCC) of the skin is considered to be the most common malignancy in people of European ancestry. It is often not clinically aggressive and has been regarded as genetically stable. However, histopathologic subtypes of BCC differ in their ability to invade surrounding tissues and recur. The aim of this work was to present a comprehensive study of chromosomal imbalances of cutaneous BCC and to correlate the findings with their histopathologic and clinical features. In all, 101 tumor samples were classified according to the current microscopic classification of BCC and then analyzed by comparative genomic hybridization (CGH). Over 60% of BCC were found to carry chromosomal imbalances - partial or whole chromosome gains and losses. Different subtypes of BCC presented common chromosomal alterations. No single chromosomal imbalance was found to be characteristic of a particular subtype of BCC, although the frequency of some chromosomal changes differed from one group to the other. The significance of chromosome 2 gains as a phenomenon that does not coexist with the losses in 9q is discussed.

The Pallister-Killian syndrome is a clinically recognizable syndrome, usually due to a tissue-specific mosaicism for a 12p isochromosome [i(12p)]. We report a rare case of Pallister-Killian syndrome with 12p mosaicism, tetrasomy/trisomy/disomy in fibroblasts and trisomy/disomy in lymphocytes. Marker chromosomes were investigated with conventional cytogenetic techniques and fluorescent in situ hybridisation (FISH). The karyotype was established as: mos47,XX,+12p/47,XX,+i(12p)/46,XX. The cytogenetic result of the extra mosaic 12p presented in lymphocytes suggested the diagnosis of trisomy 12p, although, in combination with clinical manifestations, the Pallister-Killian syndrome was considered and confirmed by the cytogenetic analysis of fibroblasts.

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PTPN13 rs989902 is significantly associated with the risk of CRC in the Polish population. Given that this report provides the first evidence of an association of PTPN13 rs989902 with the risk of CRC in a Caucasian population, further large scale studies are necessary to confirm this finding.