Gonadotropin dynamics in XX males

The genetic basis of male infertility

Defective spermatogenesis can be the end result of a multitude of causes, such as systemic disease, malnutrition, endocrinologic disorder, genetic defects, anatomic obstruction of the passage of spermatozoa, infections, and environmental toxins. A genetic basis of infertility is thought to exist in a majority of infertile men currently classified as having idiopathic infertility. Despite advances in molecular technology, the pathophysiology of spermatogenic failure in a majority of infertile men remains unknown. Although a large number of genes and loci in experimental animals are associated with sterility, the human homologues of most of these genes have not been cloned yet. Infertility is a heterogeneous syndrome in men; therefore, it is likely that a multitude of genes and loci will be implicated in different infertility subsets.

Phenotypical expression in XX males correlates with testicular response to exogenous choriogonadotropin in early infancy: does a variable degree of testicular failure determine the degree of genital ambiguity?

The 46,XX male syndrome is characterized by the presence of testicular development in subjects who lack a Y chromosome. The majority of patients have male external genitalia without ambiguity; however, 10-15% show diverse degrees of hypospadias. Testicular function is normal at birth but deteriorates thereafter. However, it has not been clarified why some cases exhibit genital ambiguity. This study examined 10 affected patients, including 4 prepubertal (< 1 year old) with hypospadias (1 glandular, 1 penile, and 2 penoscrotal). In all subjects, testicular function was evaluated by performing a stimulation with choriogonadotropin. In the postpubertal individuals, basal and poststimuli testosterone were below the reference values. Prepubertal patients had age-appropriate basal test-osterone concentrations. All responded to the choriogonadotropin challenge; however, the most significant response was observed in the patient with the glandular hypospadias, the second highest response was presented by the patient with the penile hypospadias, while both patients with the penoscrotal hypospadias had the poorest responses. These results suggest that the degree of genital ambiguity is correlated with the impairment in testosterone response to choriogonadotropin in early infancy, indicating a defect in testosterone production in XX males with genital ambiguity.

Endocrinological evaluation in a case of XX male syndrome

A case of a phenotype male with 44 XX karyotype is presented. Clinical, endocrinological and anatomical findings are recorded. Serum level of FSH was elevated, LH level was normal and testosterone level was low. A subnormal response by testicular Leydig cells to hCG was observed. A dexamethasone suppression test and an ACTH test were normal. A B scan ultrasonographic examination did not show female internal genitalia, nor a hyperplasia of adrenal tissue. A review is made of the literature with theories of etiology.