Sons conceived by assisted reproduction techniques inherit deletions in the azoospermia factor (AZF) region of the Y chromosome and the DAZ gene copy number

• Published in: Human reproduction (Oxford) Vol. 23; no. 7; pp. 1669 - 1678
• Main Authors: Mau Kai, C., Juul, A., McElreavey, K., Ottesen, A.M., Garn, I.D., Main, K.M., Loft, A., Jørgensen, N., Skakkebæk, N.E., Andersen, A. Nyboe, Rajpert-De Meyts, E.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-07-2008; Oxford Publishing Limited (England)
• Subjects: Adult; AZFc; b2–b3 deletion; Biological and medical sciences; Chromosomes, Human, Y - genetics; Follicle Stimulating Hormone - blood; Gene Deletion; Gene Dosage; Gene Rearrangement; Genetic Loci; Genotype; gr–gr deletion; Gynecology. Andrology. Obstetrics; Humans; Infertility, Male - genetics; Luteinizing Hormone - blood; Male; Medical sciences; Middle Aged; Reproductive Techniques, Assisted; Risk Factors; Seminal Plasma Proteins - genetics; Testosterone - blood; Y chromosome; gr-gr deletion; b2-b3 deletion; AZFc; ART; Y chromosome; Art; Assisted procreation; Y-Chromosome; Azoospermia factor; Hereditary; Vertebrata; Mammalia; Gene; Number; Deletion; Technique
• ISSN: 0268-1161; 1460-2350
• DOI: 10.1093/humrep/den124

BACKGROUND Deletions in the azoospermia factor (AZF) region of the Y chromosome are frequent in infertile men. The clinical consequences and the mode of inheritance of these deletions are not yet clear. METHODS Y chromosome deletion mapping and quantitative PCR analysis of the DAZ-gene copy number, supplemented with haplogroup typing in deleted patients, were performed, in combination with clinical assessments in 264 fathers and their sons conceived by assisted reproduction techniques (ART), and in 168 fertile men with normal sperm concentration. RESULTS In the ART fathers group, a complete AZFc deletion was detected in 0.4% (1/264). AZFc rearrangements/polymorphisms were found in 6.8% (18/264; 95% CI: 4.4–10.5), which was significantly more frequent (P = 0.021) than in the controls (3/168; 1.8%, 95% CI: 0.6–5.1). All deletions were transmitted to the sons, without any clinical symptoms in early childhood. In the fathers, there was no significant correlation between the DAZ copy number and the severity of spermatogenic failure. CONCLUSIONS AZFc rearrangements/polymorphisms are transmitted to sons and may represent a risk factor for decreased testis function and male subfertility, which needs confirmation in further studies in larger cohorts. However, deletions of two DAZ gene copies are compatible with normal spermatogenesis and fertility.