Transferrin (TF) polymorphism in Libyans

Summary The genetic polymorphism of transferrin (TF) was investigated in 110 unrelated Libyans, using ultrathin layer polyacrylamide gel isoelectric focusing followed by staining with Coomassie brilliant blue R250. Five common and one rare phenotypes were observed. The estimated allele frequencies were as follow: TF*C1 = 0.7455, TF*C2 = 0.2091, TF*C3 = 0.0409 and TF*D = 0.0045. The theoretical exclusion rate in cases of disputed paternity is 19.2%.     

部分妇幼保健机构遗传咨询现状调查

目的 了解妇幼保健机构中遗传咨询工作的现状。 方法 采用邮寄调查表的方法对参加“中美预防神经管畸形和残疾合作项目”的33个市县的妇幼保健院(所)进行调查。 结果 33张问卷全部收回且均为有效问卷。在33所妇幼保健机构中76%(25/33)提供遗传咨询服务,其中80%(20/25)有遗传咨询或类似科室,8%(2/25)的机构的遗传咨询单独由专职咨询医生承担,8%(2/25)的遗传咨询由专职咨询医生、婚检医生、妇产科医生、儿科医生等共同承担,84%(21/25)由婚检医生单独或与妇儿临床及保健医生共同承担,32%(8/25)机构中的咨询医生没有接受过遗传咨询专业培训,76%(19/25)的机构没有遗传咨询工作指南和考核标准。67%(22/33)的机构没有遗传学实验手段,30%(10/33)的机构不提供新生儿遗传病筛查服务。 结论 妇幼保健机构中遗传咨询开展的不够广泛,从事遗传咨询工作的专业技术人员不足,机构专业设施缺乏。     

Biomarkers, screening and ethics

Rapid scientific advances, such as those in biomarker technology,have made a significant impact on the ethics and practice ofoccupational health. Biomarkers are extensively used in occupationalhealth practice. In the pre-employment stage, preventive orpredictive testing can be performed. Preventive testing aimsto avert accidents that may occur if a medically unfit workerundertakes a job that he is unable to perform. For safety sensitivejobs, routine testing of a worker's functional capacity in theactual job would suffice in most cases. However, a recentlyquotes application of a test is the screening for mutationsof the cardiac myosin-heavy chain and troponin genes among asymptomaticpersons with a family history of sudden death from hypertrophicobstructive cardiomyopathy. Predictive testing hopes to forecastthe risk of a worker developing an illness. The aims may vary.One aim may be to exclude a susceptible worker from workingin a hazardous environment. Another aim may be to avoid employmentof a worker who is likely to develop an illness which couldlead to higher employer health care costs. A pertinent questionto consider is whether the test undertaken is to benefit theindividual or to fulfil some administrative or financial need.Among exposed workers, screening may be conducted for biomarkersof exposure or effect. As the aim is to prevent the onset ofclinical illness, the physician must take responsibility forinitiating requests for screening. The appropriate responseto the effect of technical and societal advances on ethics isthe updating of ethical guidelines by the profession. However,in the context of unvalidated biomarkers being used for screening,it may be necessary to require a regulatory body to ensure thatthe tests are accurate and effective, and that they are notused to discriminate against individuals.     

甲状旁腺激素测定在慢性肾功能衰竭中的临床意义

继发性甲状旁腺功能亢进症(SHPT)是慢性肾功能衰竭(CRF)及终末期肾病(ESRD)患者常见的并发症之一，并随原发病进展而逐渐加重，而且甲状旁腺激素(PTH)是肾病进展的指标之一。作者从PTH的生理意义、在CRF或ESRD时PTH升高的原因及其临床意义、临床测定PTH浓度的方法、PTH升高与基因(CYP2D6、GSTT1及GSTMl)多态性的关系等方面，具体阐述了PTH测定的临床意义。     

精神分裂症高发家系遗传方式分析

目的 分析高发精神分裂症家系的遗传方式。方法 采用分离分析方法和多基因阈值理论对71例高发精神分裂症家系进行遗传方式分析。结果 高发精神分裂症家系遗传方式符合常染色体单基因隐性遗传,分离率P=0.2845(JP>0.05),同时也符合多基因遗传,一级亲属加权平均遗传率为(168.38±3.29％)。结论 本组精神分裂症高发家系是具有一个显性主基因的多基因遗传病,但也存在不同的遗传背景。     

HLA-DQβ遗传多态与重症肌无力的易患性

目的探讨ＨＬＡＤＱβ对重症肌无力（ＭＧ）的遗传易患性。方法采用聚合酶链反应限制片段长度多态性（ＰＣＲＲＦＬＰ）法对３５例ＭＧ患者及５０名健康对照ＨＬＡＤＱβ链对应的ＨＬＡＤＱＢ１基因进行分型，并对患者组和健康对照组的ＤＱＢ１各等位基因频率和ＤＱβ氨基酸序列进行比较分析。结果ＤＱＢ１０２０１和ＤＱＢ１０３０２的频率在患者组中升高，其中两组的ＤＱＢ１０３０２的频率差异具有显著性意义（ＲＲ＝４．４１，Ｐ＜０．０５）；ＨＬＡＤＱβ氨基端５７位的丙氨酸在患者组中显著升高（ＲＲ＝５．１０，Ｐ＜０．００５），在伴有胸腺瘤的ＭＧ患者中差异更显著（ＲＲ＝５７．８８，Ｐ＜０．００１）。结论ＨＬＡＤＱβ５７位的丙氨酸表现对中国人ＭＧ的易患性，特别是在伴有胸腺瘤的ＭＧ患者。这种易患性的遗传基础为非极性的疏水氨基酸丙氨酸替换了带负电荷的极性氨基酸天冬氨酸。     

接触低浓度苯系混合物作业工人细胞微核率及染色体断裂率的观察

目的：探讨混合苯对作业工人遗传物质是否有损害。方法：采用微核技术对混合苯作业工人４１人进行微核及染色体断裂率观察。结果：工人的微核率、微核细胞率及染色体断裂三项指标分别为１４．４９‰、１２．９７‰、１．７５％均明显高于对照组（Ｐ＜０．０１）。在岗年限６年以上组三项指标均高于在岗年限５年以下组（Ｐ＜０．０１）。结论：混合苯对作业工人遗传物质具有损害作用。其损害程度随着接触时间呈递增趋势。     

原发性失眠的5-羟色胺转运体基因遗传多态性研究

目的　探讨原发性失眠与羟色胺转运体( 5 -HTT)基因遗传多态性的关系。方法　对85例病例组和54名对照组提取外周血基因组DNA ,进行PCR扩增,分析相应的基因型,并比较两组不同基因型患者的焦虑和抑郁评分有无差异。结果　两组的5 -HTTLPR和5 -HTTVNTR的基因型、等位基因频率及不同基因型频率的两两比较均无显著性差异(P >0 .0 5) ;病例组5- HTTLPR的S/S(S组)和S/L +L/L(L组)两组之间及5- HTTVNTR的1 0 / 1 0 + 1 0 / 1 2 ( 1 0组)和1 2 / 1 2 ( 1 2组)两组之间的焦虑、抑郁量表评分比较均无显著性差异(P >0 . 0 5)。结论　5- HTTLPR和5 -HTTVNTR两种基因遗传多态性与原发性失眠的关系尚需进一步探讨。     

杂合突变型COL4A5基因表达与Alport综合征女性表型关系分析

目的 探讨编码基因COL4A5 mRNA的表达与X连锁Alport综合征(XLAS)女性临床表型之间的关系。方法 以已确诊其COL4A5为缺失突变的女性为研究对象，以其皮肤成纤维细胞中α5(Ⅳ)链的突变mRNA表达量占总mRNA表达量(即突变mRNA表达量与正常mRNA表达量之和)的50％为界分组，并结合临床资料分析。结果 各患者均有持续性镜下血尿，突变mRNA表达多于正常mRNA表达的患者还常有肉眼血尿，而且伴有程度较重的蛋白尿：而突变mRNA表达少于或等于正常mRNA表达的患者常无肉眼血尿。而且不伴有蛋白尿或者蛋白尿的程度轻微。各患者的蛋白尿程度与其α5(Ⅳ)链的突变mRNA与总mRNA之比呈直线相关，有显著统计学意义。结论 突变COL4A5基因mRNA表达量的差异可能是影响XLAS女性临床表型的因素之一，突变等位基因mRNA的表达量居多的XLAS女性临床症状相对重。     

Medulloblastoma in a child with Duchenne muscular dystrophy

Materials and methods A 7-year-old boy diagnosed with Duchenne muscular dystrophy (DMD) presented with clinical features of raised intracranial tension. A CT scan revealed an enhancing vermian mass extending on to the fourth ventricle, which was excised and reported to be medulloblastoma. The patient was treated with craniospinal radiotherapy but progressed after 6 months. Discussion Neoplasms associated with DMD are rare and the present case may well be the first one with medulloblastoma. Interestingly, all neoplasms associated with DMD reported so far have been round cell tumors, which may lead to insights into their possible molecular associations.