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Male sex determination in humans is controlled by the SRY gene, which encodes a transcriptional regulator containing a conserved high mobility group box domain (HMG-box) required for DNA binding. Mutations in the SRY HMG-box affect protein function, causing sex reversal phenotypes. In the present study, we describe a 19-year-old female presenting 46,XY karyotype with hypogonadism and primary amenorrhea that led to the diagnosis of 46,XY complete gonadal dysgenesis. The novel p.E89K missense mutation in the SRY HMG-box was identified as a de novo mutation. Electrophoretic mobility shift assays showed that p.E89K almost completely abolished SRY DNA-binding activity, suggesting that it is the cause of SRY function impairment. In addition, we report the occurrence of the p.G95R mutation in a 46,XY female with complete gonadal dysgenesis. According to the three-dimensional structure of the human SRY HMG-box, the substitution of the conserved glutamic acid residue by the basic lysine at position 89 introduces an extra positive charge adjacent to and between the positively charged residues R86 and K92, important for stabilizing the HMG-box helix 2 with DNA. Thus, we propose that an electrostatic repulsion caused by the proximity of these positive charges could destabilize the tip of helix 2, abrogating DNA interaction.

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A 14 year old girl having 10-days lumbar pain, polaquiuria and moderate pain to palpation is reported. Blood and urine analysis were normal. Abdominal ultrasound scan showed cavity free and solid, rounded, heterogeneous, intrapelvic mass compressing bladder and uterus. Magnetic resonance image was performed showing right gonad compromise with extensive liver and sacro-lumbar spine invasion. Tumoral markers were ruled out. During surgery, primary tumor mass localizad in the right gonad was completely excised. Melanotic peritoneal and hepatic disemination were observed. The patient had left streak gonad and infantile uterus (2 x 3 cm). As gonad dysgenesia was suspected, high resolution cromosomic study was performed and resulted in cariotype 46 XY. Microscopy of the resected gonad showed primary gonad melanoma. Chemotherapy was instituted with no tumor response and the patient died two month later.

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Presentamos el caso de una mujer de 26 años que tuvo su menarquia a los 16 seguida de dos ciclos menstruales espontáneos y luego amenorrea. Su examen físico mostró una estatura normal, proporciones corporales eunucoides, desarrollo mamario adulto, distribución pilosa normal, genitales externos femeninos normales sin virilización, útero hipoplásico y anexos no palpables, lo que fue confirmado por ecografía. Su cariotipo fue 46, XY. Tenía niveles plasmáticos elevados de FSH y normales de testosterona. Con el diagnóstico de disgenesia gonadal pura XY en su forma completa, se realizó gonadectomía bilateral. El estudio microscópico, demostró presencia de tejido fibroso tipo estroma ovárico con múltiples calcificaciones nodulares, sin estructuras foliculares, ni células de Leydig. Sertoli o carácter maligno. El cariotipo de ambas gónadas fue 46, XY. El estudio molecular de su ADN genoma mostró ser SRY positivo. Se discuten las bases del diagnóstico de disgenesia gonadal completa XY en este caso y los posibles mecanismos etiopatogénicos involucrados

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We tested a female patient with 46,XY karyotype and pure gonadal dysgenesis for the presence of the SRY gene and for mutations within the SRY conserved domain. A point mutation was identified at nucleotide position 209 with respect to the first ATG. The base substitution is a G-->A transition in the first nucleotide of codon 70 which changes a tryptophan (TGG) to a stop codon (TAG). Even though the father was not available for investigation we assumed that it is a de novo mutation, since it probably generates a nonfunctional truncated protein.

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Os autores apresentam um caso de paciente com fenótipo feminino, agenesia de vagina, cariótipo 46, XY e presença de gônada rudimentar, calssificam como disgenesia gonadal pura e utilizam a técnica de neovaginoplastia com âmnio, tendo sucesso.

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Os autores relatam um caso de disgenesia gonadal 46,XY, forma incompleta, exporádica, que aos 20 anos de idade näo apresentavam tumor gonadal. Descrevem o tratamento cirurgico e hormonal e chamam a atençäo para o diagnóstico diferencial entre disgenesia gonadal pura e mista

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