A Cytogenomic Approach in a Case of Syndromic XY Gonadal Dysgenesis.

This is the first molecular characterization of a female XY patient with an Xp duplication due to an X;22 translocation. Array CGH detected a copy number gain of ∼36 Mb in the Xp22.33p21.1 region involving 150 genes. Clinical and molecular studies described in the literature have suggested DAX1 duplication as the major cause responsible for a sex reversal phenotype. Additionally, the interaction between genes and their possible role in clinical features are presented to support the discussion on genotype-phenotype correlation in cases of syndromic XY gonadal dysgenesis.

46,XY and 45,X/46,XY testicular dysgenesis: similar gonadal and genital phenotype, different prognosis.

The objective of this study was to describe the change in diagnosis and prognosis of a child with testicular dysgenesis and 46,XY karyotype after detection of a 45,X cell line and to discuss the difficulties caused by the terms mixed gonadal dysgenesis (MGD) and XY partial gonadal dysgenesis (XYPGD). One case was reported including clinical and laboratory findings of a child of 41-day-old infant with 1.3-cm phallus, penoscrotal hypospadias and left prepubertal testis. Karyotype 46,XY (16 cells), normal hormone levels. Right streak gonad, epididymis and müllerian remnants were removed; initial diagnosis was XYPGD. Persistent growth retardation led to further cytogenetic analysis (50 cells) and detection of a 45,X cell line. Detection of a 45,X lineage changed both the diagnosis to MGD and also the prognosis.The number of cells analyzed in karyotyping is critical. Use of MGD and XYPGD to designate both a histological picture and a syndromic diagnosis, results in lack of emphasis on clinical differences between 46,XY and 45,X/46,XY subjects.

46,XY DSD due to impaired androgen production.

Disorders of androgen production can occur in all steps of testosterone biosynthesis and secretion carried out by the foetal Leydig cells as well as in the conversion of testosterone into dihydrotestosterone (DHT). The differentiation of Leydig cells from mesenchymal cells is the first walk for testosterone production. In 46,XY disorders of sex development (DSDs) due to Leydig cell hypoplasia, there is a failure in intrauterine and postnatal virilisation due to the paucity of interstitial Leydig cells to secrete testosterone. Enzymatic defects which impair the normal synthesis of testosterone from cholesterol and the conversion of testosterone to its active metabolite DHT are other causes of DSD due to impaired androgen production. Mutations in the genes that codify the enzymes acting in the steps from cholesterol to DHT have been identified in affected patients. Patients with 46,XY DSD secondary to defects in androgen production show a variable phenotype, strongly depending of the specific mutated gene. Often, these conditions are detected at birth due to the ambiguity of external genitalia but, in several patients, the extremely undervirilised genitalia postpone the diagnosis until late childhood or even adulthood. These patients should receive long-term care provided by multidisciplinary teams with experience in this clinical management.

Incomplete regression of müllerian ducts in the androgen insensitivity syndrome.

The biochemical and histological features of two related patients with the complete form of the androgen insensitivity syndrome (AIS) coexisting with incomplete regression of the Müllerian ducts are described. Both patients presented unilateral Müllerian derivatives (fallopian tube) identified by microscopic examination of surgically excised internal genital tissue. Biochemical studies performed in genital skin-derived fibroblasts from one of the affected subjects showed the existence of a specific and saturable 8.2 to 8.4 S cytosolic and 3.4 S nuclear androgen receptor exhibiting a Kd of 1.32 nmol/L. These mutant cells, however, clearly presented a significantly low maximal nuclear [3H]-5 alpha-dihydrotestosterone uptake (71.0 fmol/mg of deoxyribonucleic acid [DNA]; control strain, 284 fmol/mg DNA). Thus, an impaired uptake of the androgen receptor complex at the nuclear level was probably the cause of the complete absence of phenotypic expression of androgen action in this family. The overall findings are on line with the well-demonstrated genetic and molecular heterogeneity of the AIS.

A new familial syndrome of 46,XY gonadal dysgenesis with anomalies of ectodermal and mesodermal structures.

Two 46,XY phenotypic female siblings, aged 1 1/2 and 8 1/2 years, have peculiar facies, cardiac, renal, musculoskeletal, and ectodermal anomalies, short stature, streak gonads, and mild developmental delay. Previous reported cases of 46,XY gonadal dysgenesis have not had major associated malformations. These children present a new constellation of anomalies unlike those seen in other types of gonadal dysgenesis and represent a new familial syndrome of 46,XY gonadal dysgenesis.

Embryonic testicular regression syndrome: variable phenotypic expression in siblings.

Two 46,XY agonadal siblings with variable degrees of sexual ambiguity are described. The eldest child is a phenotypic male with micropenis. The younger patient, a phenotypic female with slight fusion of the genital folds and absent müllerian ducts, conforms to the criteria usually accepted for the diagnosis of true agonadism. Coexistence of anorchia and true agonadism in the same sibship supports the hypothesis, suggested by others, that both disorders are related and are due to the regression of the embryonic testes.