Wiland Ewa, Midro Alina T, Panasiuk Barbara, Kurpisz Maciej
Institute of Human Genetics, Polish Academy of Sciences, ul. Strzeszyńska 32, 60-479 Poznań, Poland.
J Androl. 2007 Mar-Apr;28(2):262-72. doi: 10.2164/jandrol.106.000919. Epub 2006 Oct 4.
Reciprocal chromosomal translocations (RCT) have long been recognized as important etiological factors in reproductive failure. In the present study, the meiotic segregation patterns of the spermatozoa of two related t(4;5)(p15.1;p12) carriers (proband and his father) were compared to the empirical data from a three-generation pedigree for risk assessment. Cytogenetic analysis of the metaphase chromosomes was performed, and triple color fluorescence in situ hybridization (FISH) was applied to the sperm heads. Similar patterns of meiotic segregation were observed for both carriers, despite the finding of teratozoospermia in the proband but not in his father. In addition, an increase of aneuploidy in chromosome 15 in the proband and aneuploidy of chromosomes X and Y in the father were observed. The high rate of miscarriages (6/10 pregnancies and 4/7 pregnancies after ascertainment correction) in this family could be explained by the genetically unbalanced karyotype and fertilization mediated by the unbalanced spermatozoa observed for both men at a frequency of more than 60%. The risk assessment for unfavorable pregnancy outcomes was predicted as 1.6% for unbalanced progeny at birth and about 30% for miscarriage. These figures may be used as guidelines for the genetic counseling of families with similar RCT.
相互染色体易位（RCT）长期以来一直被认为是导致生殖失败的重要病因。在本研究中，将两名相关的t(4;5)(p15.1;p12)携带者（先证者及其父亲）精子的减数分裂分离模式与一个三代家系的经验数据进行比较，以进行风险评估。对中期染色体进行了细胞遗传学分析，并将三色荧光原位杂交（FISH）应用于精子头部。尽管先证者存在畸形精子症而其父亲没有，但两名携带者观察到相似的减数分裂分离模式。此外，还观察到先证者中15号染色体非整倍体增加，以及父亲中X和Y染色体非整倍体增加。该家族中高流产率（确诊校正后10次妊娠中有6次，7次妊娠中有4次）可由遗传不平衡核型以及在两名男性中观察到的频率超过60%的不平衡精子介导的受精来解释。预测出生时不平衡后代不良妊娠结局的风险评估为1.6%，流产风险约为30%。这些数据可作为类似RCT家系遗传咨询的指导原则。
