Service de Biologie de la Reproduction, Centre Hospitalier Universitaire, Strasbourg, France.
Am J Hum Genet. 2011 Mar 11;88(3):344-50. doi: 10.1016/j.ajhg.2011.01.018.
Globozoospermia, characterized by round-headed spermatozoa, is a rare (< 0.1% in male infertile patients) and severe teratozoospermia consisting primarily of spermatozoa lacking an acrosome. Studying a Jordanian consanguineous family in which five brothers were diagnosed with complete globozoospermia, we showed that the four out of five analyzed infertile brothers carried a homozygous deletion of 200 kb on chromosome 12 encompassing only DPY19L2. Very similar deletions were found in three additional unrelated patients, suggesting that DPY19L2 deletion is a major cause of globozoospermia, given that 19% (4 of 21) of the analyzed patients had such deletion. The deletion is most probably due to a nonallelic homologous recombination (NAHR), because the gene is surrounded by two low copy repeats (LCRs). We found DPY19L2 deletion in patients from three different origins and two different breakpoints, strongly suggesting that the deletion results from recurrent events linked to the specific architectural feature of this locus rather than from a founder effect, without fully excluding a recent founder effect. DPY19L2 is associated with a complete form of globozoospermia, as is the case for the first two genes found to be associated with globozoospermia, SPATA16 or PICK1. However, in contrast to SPATA16, for which no pregnancy was reported, pregnancies were achieved, via intracytoplasmic sperm injection, for two patients with DPY19L2 deletion, who then fathered three children.
圆头精子症的特征是精子头部呈圆形,是一种罕见的(在男性不育患者中<0.1%)严重的畸形精子症,主要由缺乏顶体的精子组成。我们研究了一个约旦近亲家族,其中 5 个兄弟被诊断为完全圆头精子症,结果表明,5 个分析的不育兄弟中有 4 个携带染色体 12 上仅包含 DPY19L2 的 200 kb 纯合缺失。在另外 3 个无关的患者中也发现了非常相似的缺失,这表明 DPY19L2 缺失是圆头精子症的主要原因,因为在分析的 21 名患者中有 19%(4 名)存在这种缺失。缺失最有可能是由于非等位基因同源重组(NAHR)引起的,因为该基因被两个低拷贝重复序列(LCRs)包围。我们在来自三个不同来源和两个不同断点的患者中发现了 DPY19L2 缺失,这强烈表明缺失是由与该基因座特定结构特征相关的反复事件引起的,而不是由奠基者效应引起的,但尚未完全排除近期的奠基者效应。DPY19L2 与完全型圆头精子症有关,就像前两个与圆头精子症相关的基因 SPATA16 或 PICK1 一样。然而,与 SPATA16 不同,后者没有报道怀孕,通过胞浆内精子注射,两名 DPY19L2 缺失患者实现了妊娠,随后他们生育了三个孩子。