SERTOLI CELL ONLY SYNDROME AND GENETICS

Genetic work up of all males with azoopsermia and severe oligospermia is necessary. Severe male factor infertility may have a presently identifiable genetic basis. Y chromosomal microdeletions (e.g., an AZFc microdeletion), karyotypic anomalies (e.g., Klinefelter Syndrome), and mutations in both alleles of the cystic fibrosis transmembrane conductance regulator (CFTR) gene may be found, depending upon the etiology of the reproductive compromise.A genetic abnormality is identified in 1/4 th of the men with extreme oligozoospermia and azoospermia. Application of ICSI in these couples can result in offspring with an enhanced risk of unbalanced chromosome complement, male infertility due to the transmission of a Y-chromosomal microdeletion, and cystic fibrosis if both partners are CFTR gene mutation carriers. Genetic testing and counselling is clearly indicated for these couples before ICSI is considered.

We get many patients with non obstructive azoospermia. In all cases of non obstructive azoospermia , Sertoli Cell Only Syndrome is an important entity as the sperm harvesting is a real challenge during TESA/Microdissection TESE. The Sertoli cell only syndrome (SCOS) also known as germinal cell aplasia is a histological diagnosis which reveals seminiferous tubules with a complete absence of all germ cells and the presence of only, as the name suggests, sertoli cells .

The cause is likely multifactorial: congenital absence of germ cell, chemicals and gonadotoxins, klienfelters syndrome are some known causes of SCOS. Y microdeletions have also been identified as the causative factors for SCOS. In the West upto 34.5% of SCOS patients were found to have associated Y chromosome microdeletion .This association has been seen with deletions of DBY (dead box on Y) gene in AZFa (azzoospermia factor a) region, microdeletions in AZFb region and DAZ (deleted in azoospermia) microdeletion in AZFc regions of the Y chromosome.Patients normally present with small to normal sized testis and azoospermic semen specimens. Phenotypically these patients are normally virilized males without gynaecomastia. Plasma FSH and LH levels are often but not invariably elevated because of the absence of germ cells, whereas plasma testosterone are normal.

Despite an apparent absence of germ cells on histologic examination, spermatozoa may be recorded in upto 50% of patients undergoing attempts at testicular sperm extraction (TESE).

MICRODISSECTION TESE CAN IMPROVE THE YIELD OF SPERM RETRIVEAL.wE ROUTINELY DO THSI PROCEDURE IN OUR HOSPITAL

This statistic is important as these patients could be candidates for In Vitro Fertilization (IVF) with Intra Cytoplasmic Sperm Injection (ICSI). Study of Y chromosome microdeletions has gained importance in this group of patients since artificial reproduction techniques (ART) can be used for them. ART bypasses the critical natural selection barriers that normally prevent genetic disease transmission. One of the major causes of concern with the use of ICSI in male infertility and nonobstructive azoospermia is the vertical transmission of genetic abnormalities to the male offspring. In the genetic abnormalities the Y microdeletions have been found in 1 -55 % cases.