Men with non obstructive infertility have been shown to carry microdeletions of AZF (Azoospermia Factor) sequences in their DNA. Three non overlapping regions have been designated as AZFa, AZFb, and AZFc, and are directly implicated in the spermatogenesis.
(Mol. Hum. Reprod. 4:739-744)
The molecular test for the Y microdeletion is based on a multiplex DNA amplification by polymerase chain reaction (PCR) of the three regions as well as other control regions STS (Sequence Tag Sites) ZFX/ZFY.
Cytogenetics is the study of an individual’s chromosomes in order to detect abnormalities. Analysis can be performed on various types of cells, such as lymphocytes and amniocytes.
Indications for Chromosome Analysis are wide-ranging:
In the Fetus:
• Abnormal prenatal screening test
• Advanced maternal age (AMA)
• Abnormal ultrasound results
In the Newborn:
• Dysmorphic syndrome, congenital malformation, psychomotor delay
• During Childhood or Adolescence:
• Mental retardation or delayed development
• Congenital malformation
During Childhood or Adolescence:
• Developmental delay or mental retardation
• Infertility workup, premature menopause, primary amenorrhea (absence of menstruation) or spermatogenesis problem
• Repeated miscarriages
• Family history of chromosome abnormalities