Sequence variants in the proximal promoter and +5.8-kb site of ABO in Koreans with weak B phenotypes.

BACKGROUND AND OBJECTIVES: Several studies on Chinese and Japanese populations have revealed that a substantial proportion of weak B subgroups are caused by variants in the major regulatory regions of ABO, the proximal promoter, CCAAT-binding factor/NF-Y binding site and +5.8-kb site. We performed molecular analyses of these regions in Koreans with weak B phenotypes. MATERIALS AND METHODS: This study included 16 samples with weak B phenotypes (4 B3 , 1 Bw , 5 A1 B3 and 6 A1 Bw ) harbouring no subgroup-causing variants in ABO exons 6 and 7. These samples were subjected to sequencing analysis of exons 1-5 and the major regulatory regions of ABO. RESULTS: Of the 16 samples, 14 were found to carry a sequence variant either in the proximal promoter (g.4991_5008del [n = 3]) or the +5.8-kb site (g.10893G>A [n = 4] and g.10925C>T [n = 7]). The remaining two samples were found to contain no subgroup-causing variants. CONCLUSION: Our study demonstrates that sequence variants in the proximal promoter and +5.8-kb site account for a substantial proportion of weak B subgroups in Koreans, suggesting that molecular analysis of these regions is essential for the accurate determination of ABO genotypes in Koreans with weak B phenotypes.

Clinical outcome of squamous cell carcinoma of the tongue in young patients: a stage-matched comparative analysis.

OBJECTIVES: The reported incidence of tongue cancer in young patients has recently increased. The aim of this study was to analyze the clinical characteristics of tongue cancer in a young group of patients, and to compare them with those of an older group of tongue cancer patients. METHODS: We retrospectively reviewed the records of 85 patients who were diagnosed with squamous cell carcinoma of the tongue. They were divided into two age groups: over 45 years of age and under 45 years. To compare the prognosis of similarly staged patients in the group, each age group was divided into the early (stage I, II) and advanced stage groups (stage III, IV), and then they were compared. The young group consisted of 23 patients and the older group had 62 patients. RESULTS: At the early stage, the clinical prognosis of the patients in both age groups was good, and no significant difference was observed. However, at the advanced stage, the overall and regional recurrence rates were significantly higher in the younger age group as compared to that in the old age group (P=0.007, P=0.001, respectively). The disease-specific survival rate of the patients in the young group was significantly lower than that in the old age group (P=0.025). CONCLUSION: Tongue cancer in young subjects has significantly different clinical outcomes according to the stage. The clinical outcome of the advanced-stage tongue cancer in young subjects was poorer than that in the older subjects. Regional recurrence seemed to be the main cause of the poor prognosis.