- 期刊
Differentiation of Fanconi Anemia from Aplastic Anemia by Chromosomal Breakage Test
以染色體斷裂試驗鑑別診斷Fanconi氏貧血及再生不良性貧血
摘要
導致再生不良性貧血(aplastic anemia)的原因相當多，Fanconi氏貧血是其中需作鑑別診斷的一種常染色體隱性(autosomal recessive)遺傳病。它亦有泛血球減少(pancytopenia)的表現，但常合併其它先天畸形及不穩定染色體等特征。吾等利用細胞遺傳學的方法來區別Fanconi氏貧血及所謂的“原發性”再生不良貧血。它的原理是利用mitomycin C及diepoxybutane兩種烴基化藥物(alkylating agent)對培養中的白血球或羊水細胞之作用。共有三十三名原因不明的骨髓衰竭病患接受檢查，其中有三名男孩確定是Fanconi氏貧血症。産前檢查並排除了一名胎兒得病的可能。本研究中診斷Fanconi氏貧血的mitomycin C最適合濃度是20ng/ml，但diepoxybutane卻無法分別這兩種貧血症。原因可能是個人遺傳體質的歧異，或是方法敏感度不夠，有待進一步評估。初步研究認爲在沒有更好的分子遺傳學方法可以使用前，mitomycin C是鑑別Fanconi氏貧血很好的一種方法。
並列摘要
Aplastic anemia (AA) is a disorder of heterogeneous pathogenesis caused by diverse etiologies. Fanconi anemia (FA) has the similar features of pancytopenia but is characterized by spontaneous or induced chromosomal instability and a variety of congenital anomalies. A cytogenetic breakage study is used to enable the diagnostic differentiation between FA and the so-called “idiopathic”AA. This method is based on the effect of the bifunctional alkylating agent mitomycin C (MMC) and alkylating mutagen diepoxybutane (DEB) on the chromosomes of peripheral lymphocytes in culture. Among thirty-three new cases of bone marrow failure with unknown etiologies, three young male patients were confirmed as victims of FA. The methodology and clinical manifestations were discussed. A prenatal screening was also performed to exclude the possibility of homozygous FA in one fetus at risk. The adequate dose of MMC used in our tests for diagnosis of FA were 20 ng/mL, while DEB did not work. These findings may suggest genetic diversity or other contributing factors in the pathogenesis of FA.