Question: What is (are) Sertoli cell-only syndrome ?
Answer: Sertoli cell-only syndrome (SCO syndrome) is a condition of the testes that causes infertility in males due to having only Sertoli cells (cells that nurture immature sperm) lining the seminiferous tubules (tubes inside the testicles where sperm develop). Men typically learn they are affected between ages 20-40 when being evaluated for infertility and are found to have no sperm production (azoospermia). The diagnosis is made based on testicular biopsy findings. Other signs and symptoms are rare, but are secondary to the underlying condition causing SCO syndrome. Most cases are idiopathic (of unknown cause), but causes may include deletions in the azoospermia factor (AZF) region of the Y chromosome, or Y-chromosome microdeletions (referred to as Y chromosome infertility); Klinefelter syndrome; exposure to chemicals and toxins; history of radiation therapy; and history of severe trauma. There is not currently a known effective treatment for the condition. When no germ cells are visible in any seminiferous tubules it is considered SCO type I; if germ cells are present in a minority of tubules is it considered SCO type II.
Source: GARD

Question: What are the symptoms of Sertoli cell-only syndrome ?
Answer: What are the signs and symptoms of Sertoli cell-only syndrome? The Human Phenotype Ontology provides the following list of signs and symptoms for Sertoli cell-only syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of metabolism/homeostasis - Abnormality of the thorax - Gynecomastia - Obesity - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD