女性性早熟患儿雌激素受体突变的检测

目的：本研究为探讨女孩性早熟患者雌激素受体基因编码的可能完善。方法：收集了16例未见血液雌激素水平升高的临床女孩性早熟患者的外周血样本，抽提血液DNA，以PCR—SSCP方法筛查雌激素受体基因编码区的可能突变。结果：在l例患者的雌激素受体基因8号外显子发现单链构象变化。测序结果证明单链构象变化是由1个单核苷酸突变引起，此突变发生于编码548位精氨酸密码子，1个C—T转换导致精氨酸残基被半胱氨酸所替代。这一突变使DNA序列中产生1个BtsL酶切位点，可通过P(R-RFLP对突变进行快速甄别，实验证明此患者为Arg548／Cys548杂合体。结论：由于这一残基在不同动物ER中的保守性质、以及突变所造成的疏水性的急剧加大，推测此突变将强烈改变雌激素受体的性质。

SCREENING OF ESTROGEN RECEPTOR GENE MUTATION IN PRECOCIOUS PUBERTY GIRLS WITHOUT CIRCULATING ESTROGEN LEVEL ELEVATION

For the purpose of screening possible mutations in estrogen receptor gene, leukocyte genomic DNA samples were collected in 16 girls with precocious puberty without elevation of estrogen level, and analyzed using PCR-SSCP method. One sample showed single strand conformation change in exon 8. Sequencing of this fragment proved that this change was caused by a C-T transition in one of the patients, which results in the replacement of arginine by cystine at position 548 of ESR1 protein. This mutation created an extra BtsI digest site in exon 8 and made it can be identified by PCR-PFLP method. And the patient was proved to be Arg548/Cys548 heterozagous. This mutation increased hydrophobility dramatically. The position and the conservative of this residue in vertebrates suggest this mutation might alter ESR1 function. It is proposed that this mutation may greatly alter the function of estrogen receptor.