DAX1 and X-linked adrenal hypoplasia congenita: clinical and molecular analysis in five patients.
OBJECTIVE
Mutations in the gene coding for the orphan nuclear receptor DAX1 cause X-linked adrenal hypoplasia congenita (AHC). Affected boys usually present with primary adrenal failure in early infancy or childhood. Impaired sexual development due to hypogonadotropic hypogonadism becomes manifest at the time of puberty. Moreover, evidence from Dax1 knockout mice and a limited number of patients with AHC, suggests that mutations in DAX1 may directly cause abnormalities in spermatogenesis. The aim of this study was to characterize clinically and genetically five patients with AHC.


METHODS
DNA sequencing analysis, endocrine testing, testicular ultrasound and semen analysis with 1-year follow-up after gonadotropin treatment.


METHODS
We report on five men with classic AHC manifestations. Genomic DNA was extracted from patients' peripheral blood leukocytes and the coding region, splice sites, and promoter (-240 bp) region of DAX1 were directly sequenced.


RESULTS
Three known and two novel mutations were detected in the DAX1 coding sequence in these patients. Semen analysis was performed in four of the five patients and showed azoospermia. Twelve-month treatment with gonadotropins did not restore fertility in these patients. All patients showed a normal testicular Doppler ultrasound, in contrast with that observed in Dax1-deficient mice, which display abnormalities in the rete testis.


CONCLUSIONS
These cases further expand the number of DAX1 mutations reported in the literature, as well as our clinical knowledge of this rare disease.
Mantovani
Giovanna
G
Institute of Endocrine Sciences, University of Milan, Padiglione Granelli, Ospedale Maggiore IRCCS, Via F. Sforza 35, 20122 Milan, Italy. giovanna.mantovani@unimi.it
De Menis
Ernesto
E
Borretta
Giorgio
G
Radetti
Giorgio
G
Bondioni
Sara
S
Spada
Anna
A
Persani
Luca
L
Beck-Peccoz
Paolo
P
D000293:Adolescent; D000309:Adrenal Insufficiency / Q000000981:diagnostic imaging* / Q000235:genetics*; D000328:Adult; D041321:Chromosomes, Human, X; D057137:DAX-1 Orphan Nuclear Receptor; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D016368:Frameshift Mutation; D017353:Gene Deletion; D006801:Humans; D007006:Hypogonadism / Q000000981:diagnostic imaging / Q000235:genetics; D008297:Male; D011401:Promoter Regions, Genetic / Q000235:genetics; D022821:RNA Splice Sites / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D013737:Testis / Q000000981:diagnostic imaging; D014463:Ultrasonography
D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; C539965:NR0B1 protein, human; C539966:Nr0b1 protein, mouse; D022821:RNA Splice Sites; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins