Meiotic arrest at the midpachytene stage in a patient with complete azoospermia factor b deletion of the Y chromosome.

OBJECTIVE

To study the meiosis of a patient with complete azoospermia factor (AZF)b deletion of the Y chromosome.

DESIGN

Case report.

SETTING

La Conception University Hospital, Marseille, France.

PATIENT(S): One azoospermic patient.

INTERVENTION(S): Yq deletion testing, testicular sperm extraction, and meiotic study with immunocytochemistry.

MAIN OUTCOME MEASURE(S): Abnormal synapsis rates in spermatocytes.

RESULT(S): We found that most spermatocytes were at an early stage of meiosis. Half of the meiotic germ cells analyzed showed asynapsis, which was mostly extended or total. Discontinuity in the synaptonemal complex was seen in one third of the meiotic cells analyzed. An unusually small number of normal pachytene nuclei were found, all at early pachytene substages.

CONCLUSION(S): This is the first demonstration that the synaptic process is impaired in a man with complete deletion of the AZFb interval. Our findings provide evidence that the pachytene checkpoint is situated at the midpachytene substage in humans.