describe how deletions in the Y chromosome could lead to male infertility?

Answer 1

A deletion of the Y chromosome would be an XO female.

Answer 2

There are two ways in which y chromosome deletions could cause male infertility, the first is that an incomplete set of chromosomes are being passed on to the fetus triggering abortion, and the second is that the potential father lacks the genes responsible for sperm production.

Minor deletions in the Y chromosome are unlikely to lead to infertility, the loss of particular loci may however produce a phenotypic effect in any offspring (loss of SRY for example). Although nulisomy Y is not classically considered overly pathogenic larger deletions or complete loss of the Y chromosome in gametes (through mosaicism in the father, or non-disjunction) can lead to spontaneous abortion of a fetus.

There are three regions on the Y chromosome named azoospermia factor (AZF) regions a, b, and c. If the chromosome loss in the Y gene of the potential father removes one or more of these AZF regions responsible for sperm production then the individual will be infertile. Currently there is a lot of literature regarding AZFa whilst the larger regions AZFb and AZFc are less well researched.

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