Gastrointestinal stromal tumor in an XYY/XY male

Constitutional duplication of a region of chromosome Yp encoding AMELY, PRKY, and TBL1Y: implications for sex chromosome analysis and bone marrow engraftment analysis

Amelogenin has chromosome X (AMELX) and Y (AMELY) homologs that can be differentiated based on the length of polymerase chain reaction (PCR) amplification products. In addition to being useful for gender identification, analysis of amelogenin has utility for monitoring bone marrow engraftment in patients after a sex-mismatched bone marrow transplant, characterizing sex chromosome abnormalities, and for forensic purposes for analyzing mixtures of male and female DNA. Here, we describe two brothers in which PCR analysis demonstrated twofold greater AMELY products compared with AMELX products. Karyotype and X/Y fluorescence in situ hybridization analysis demonstrated a single copy of the X and Y chromosomes without any identifiable abnormalities. Oligonucleotide comparative genomic hybridization array analysis demonstrated a duplication of a portion of chromosome Yp that encompassed a region of at least 2.6 Mb but not greater than 4.0 Mb. The amplified region contains the genes AMELY, transducin (beta)-like 1 protein Y (TBL1Y), and protein kinase Y (PRKY). To our knowledge, duplication of this region has not previously been reported. The family history is unremarkable, and the brothers are without ap-parent dysmorphic features. Although this and other genetic variants involving AMELY are uncommon, one should use caution when using amelogenin for sex chromosome analysis and bone marrow engraftment analysis.

Mortality and cancer incidence in males with Y polysomy in Britain: a cohort study

The mortality and cancer incidence risks among males with Y polysomy are unknown because there have been no large long-term cohort studies carried out of such men. We conducted a cohort study of 667 men diagnosed with the abnormality in Britain since 1959 to compare their mortality and cancer incidence rates with those of the general population. Sixty deaths occurred during follow-up to December 2005, twice the number expected from general population rates (standardised mortality ratio (SMR) = 2.0 (95% confidence interval (CI) 1.5-2.6)). Significantly raised mortality was observed for diseases of the nervous system (SMR = 7.0, 95% CI: 2.3-16.4), circulatory system (SMR = 2.1, 95% CI: 1.3-3.2), respiratory system (SMR = 4.0, 95% CI: 1.8-7.5), genitourinary system (SMR = 10.2, 95% CI: 1.2-36.9), and congenital anomalies (SMR = 11.9, 95% CI: 3.2-30.5). Four of the five nervous system deaths were from epilepsy, the risk of death from this condition being more than 20-fold raised. The rates of cancer incidence and mortality among these men was not significantly different from those in the general population. This study provides evidence that mortality rates from several specific causes are raised among men with Y polysomy. The use of these data in genetic counselling should be cautious particularly for cases of Y polysomy that are detected prenatally. Further investigations are required to confirm these findings and to elucidate the possible role of genes on the Y chromosome in the aetiology of these causes of death.

Population-based study of renal cell carcinoma in children in Germany, 1980-2005: more frequently localized tumors and underlying disorders compared with adult counterparts

BACKGROUND

Childhood renal cell carcinomas (RCCs) differ histologically and biologically from their adult counterparts. The characteristics of RCC-affected children and their tumors, the influence of treatment, and outcome have so far not been studied in a nonselected, population-based cohort.

METHODS

A retrospective analysis was undertaken of RCC patients less than 16 years old reported to the German Childhood Cancer Registry and to the Kiel Paediatric Tumor Registry from 1980 to 2005.

RESULTS

Forty-nine RCC in children (24 boys, 25 girls) with a median age of 10.6 years were identified. In about every third child possibly RCC-related underlying disorders (tuberous sclerosis, neuroblastoma, teratoma with chemotherapy, Saethre-Chotzen syndrome, chronic renal failure) or related diseases in their family were found. The pathologic subtypes were papillary in 16 (33%), translocation type in 11 (22%), unclassified in 8 (16%), and rarely clear-cell (n = 3) or others. Thirty-four (69%) patients had localized RCC, 8 (16%) patients regional lymph node metastases, and 4 (8%) patients distant metastases. Event-free survival and overall survival rates at 5 years were 96% for localized RCC, 69% and 75% for regional lymph node-positive, 25% and 33% for distant metastatic RCC, respectively. Two of 4 patients with distant metastases received immunotherapy combined with chemotherapy and surgery, both are alive, 1 of them disease-free for 6.9 years.

CONCLUSIONS

Pediatric RCCs are predominantly localized diseases. Children with RCC frequently suffer underlying disorders. Survival rates in localized and regional lymph node-positive cases are favorable. Because of the rarity of RCC in childhood, an international study is necessary.