很多独特的临床综合征(DS)都非随机地出现7号染色体缺失或长臂部分缺失,涉及的有关基因尚不清楚,但很可能位于7号染色体的长臂。因为不管是出现部分缺失(7q~-)还是7号单体,其临床特征相同,即预后很差,最后发展为明显的非淋巴细胞性白血病或死于血小板减少或感染。Down 综合征患儿的白血病前期报道甚少,本文报道三例 DS 和白血病前期患儿伴7号染色体缺失或部分缺失。例1:DS 男孩,出生30个月后于1987年7月发病。表现为贫血,血小板减少和肝 Many of the unique clinical syndromes (DSs) do not randomly show chromosome 7 deletion or long-arm deletion, and the genes involved are not yet known, but are probably located on the long arm of chromosome 7. Because either the partial deletion (7q ~ -) or the number 7 monomer, the same clinical features, that is, the prognosis is poor, and finally developed into obvious non-lymphocytic leukemia or died of thrombocytopenia or infection. Down syndrome children with pre-leukemia rarely reported in this article reported three cases of DS and pre-leukemia with chromosome 7 missing or partial deletion. Example 1: DS boy, born 30 months after onset in July 1987. Manifested as anemia, thrombocytopenia and liver