Genetic causes of male infertility

Analysis of microdeletions of the AZF locus of the Y chromosome (8 loci)

Deletions of the AZF locus are the #2 most common among all genetic causes of male infertility (after karyotypic disorders).

what is a deletion?

Deletions are a type of chromosomal mutations characterized by the loss (loss) of a section of a chromosome.

What is AZF?

The AZF (Azoospermia Factor) locus or region is a section of the Y chromosome that contains genes responsible for the control and development of male germ cells (spermatogenesis).

The AZF locus is in the long arm of the Y chromosome (Yq11).

Genes located at this locus play an important role in the process of spermatogenesis.

The AZF locus is divided into 3 sites: AZFa, AZFb, and AZFc .

Deletions at the AZF locus can be complete, i.e. completely deleting one of the AZF regions or more, and partial, when they do not completely take over any of its three regions. The prognosis for the possibility of obtaining spermatozoa depends on this.

ANALYSIS ALLOWS:

establish the genetic cause of spermatogenesis disorders.
choose an appropriate treatment tactic for the patient.
to decide if assisted reproductive technology is needed.
to predict the possibility of obtaining spermatozoa for ICSI, IVF, and testicular biopsy.
to predict for male offspring the possibility of inheriting the father's reproductive problems.

ANALYSIS IS RECOMMENDED

all patients involved in infertility treatment by ICSI, IVF

in the nonobstructive form of azoospermia

when the concentration of spermatozoa in the ejaculate is less than 10 million/ml (WHO)

WHAT'S THE RESULT?

AZFa sY84, sY86 deletion

negative prognosis with respect to sperm production

AZFb sY127, sY134 deletion

negative prognosis with respect to sperm production

AZFc sY254, sY255 deletion

high probability of obtaining sperm, in 50-70% of cases it is possible to obtain sperm suitable for artificial insemination.

SRY Deletion

Gonad differentiation disorder (reproductive glands) of the male type, female phenotype.

Absence of the entire AZF locus

Indicates the impossibility of obtaining sperm.

SAMPLE RESULT

FREQUENCY OF OCCURRENCE

DELETIONS AZFa, AZFb, AZFc

IN KAZAKHSTAN

The highest number of deletions was found in the AZFc subregion (53.5%), whereas the frequency of deletions in AZFa, AZFb, or combined deletions of two and three subregions was 5.0%, 15.0%, and 26.5%, respectively.

( According to JSC "Scientific Center of Urology named after academician B.U. Dzharbusynov", Almaty, Republic of Kazakhstan, 2019)

AS AZF MICRODELETIONS

WILL AFFECT THE UNBORN CHILD?

All male children will inherit changes in the Y chromosome from the father. Boys born after ICSI to fathers with microdeletions in the Y chromosome must be monitored to assess their fertility status.

Violations will not be passed on to girls.

SCIENTIFIC ARTICLES

on the topic of microdeletions of the Y chromosome

AZF Y-CHROMOSOME GENE MICRODELETIONS AND CFTR GENE POLYMORPHISM IN PATIENTS WITH AZOOSPERMIA AND SEVERE OLIGOZOOSPERMIA. JSC "Scientific Center of Urology named after academician B.U. Dzharbusynov", Almaty, Republic of Kazakhstan

MOLECULAR GENETIC DIAGNOSIS IN MALE INFERTILITY. Molecular genetic laboratory TreeGene. Kazakhstan, Almaty - 2016. -№ 1(16).-С.30-33.

Molecular genetic studies in male infertility available in Kazakhstan. Degemerzanova N.K., Solomadin M.V. AZF-microdeletions of Y-chromosome. KMJ (Kazakhstan Medical Journal). - 2012. -№6 (30). - С. 86-89.

AZF deletions as a frequent genetic cause of infertility in males: current state of research. V.B. CHERNY. Medical Genetics Research Center, Russian Academy of Medical Sciences; Moscow State University of Medicine and Dentistry

MALE INFERTILITY. G.R. Dohle, T. Diemer, A. Giwercman, A. Jungwirth, Z. Kopa, C. Krausz Translation: K.A. Shiranov Scientific editing: A.S. Akopyan

FREQUENCY AND SPECTRUM OF AZF-MICRODELETIONS IN MEN WITH INFERTILITY. "Kemerovo State Medical University, Ministry of Health of the Russian Federation, Kemerovo, Russia