USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Primary hypogonadism due to Leydig cell dysfunction may result from which of the following conditions?

1. Mullerian Duct Abnormalities

2. Primary hypogonadism due to Leydig cell + seminiferous tubule dysfunction

3. Secondary hypogonadism

4. Pseudopseudohypoparathyroidism

The correct answer is: Primary hypogonadism due to Leydig cell + seminiferous tubule dysfunction

Primary hypogonadism due to Leydig cell dysfunction specifically refers to conditions in which the Leydig cells, which are responsible for testosterone production, are impaired. When Leydig cells are dysfunctional, there is a direct impact on testosterone levels, leading to primary hypogonadism. Option B accurately reflects a scenario where there is a combination of Leydig cell dysfunction along with seminiferous tubule dysfunction. This combination would result in inadequate testosterone production due to the impaired Leydig cells, as well as reduced spermatogenesis due to seminiferous tubule dysfunction. Therefore, this condition encompasses primary hypogonadism resulting from the failure of both cell types essential for normal male reproductive function. In this context, other options do not lead to Leydig cell dysfunction directly. Mullerian Duct Abnormalities primarily result in structural abnormalities of the reproductive system and are not directly related to the function of Leydig cells. Secondary hypogonadism indicates a problem at the hypothalamic or pituitary level, which is not directly related to Leydig cell dysfunction. Pseudopseudohypoparathyroidism is a genetic disorder associated with a lack of response to parathyroid hormone but does not involve Leydig cell malfunction. Therefore, the assessment