Deleción 9p-. Disgenesia gonadal asociada a retraso mental e hipoplasia del cuerpo calloso. ¿Síndrome de genes contiguos? / Chromosome 9P deletion: Gonadal dysgenesis associated with mental retardation and hypoplasia of the corpus callosum: a contiguous gene syndrome

Antecedentes: Son muchos los genes que se han implicado en la diferenciación testicular, cuyas alteraciones dan cuadros de trastornos de la diferenciación sexual y cariotipo 46XY. Caso clínico: Recién nacido con hipospadias interescrotal, gónadas palpables y pene hipoplásico. Cariotipo 46XY. Ecografía abdominal: testes y sin restos müllerianos. Buena respuesta al test corto de gonadotropinas. Al año presenta retraso psicomotor, hipotonía. Resonancia magnética con atrofia de sustancia blanca frontotemporal y disminución del cuerpo calloso. Biopsia testicular compatible con disgenesia gonadal. Dada la situación intersexual al nacimiento, el retraso psicomotor y la presencia de dismorfias faciales se solicita cariotipo de alta resolución: deleción 46, XY, del(9p)(p23-pter).ish tel (9p-). Comentarios: Son muchos los genes implicados en la diferenciación testicular, algunos de ellos también influyen sobre el desarrollo de otros tejidos. En el brazo corto del cromosoma 9 se encuentran dos genes, DMRT1 y DMRT2, implicados en la diferenciación sexual, cuyas alteraciones también han sido descritas como causantes de retraso mental. En la evaluación de los trastornos de la diferenciación sexual son muy importantes los signos acompañantes para poder orientar el estudio genético (AU)

Background: Many genes are involved in testicular differentiation. The alterations of these genes are responsible for sexual differentiation disorders with 46 XY karyotype. Case: We report the case of a newborn who had an interscrotal hypospadias, palpable gonads and hypoplastic penis. Karyotype 46 XY. Abdominal ultrasound revealed testes and absence of Müllerian remnants. There was a good response to the short gonadotrophin test. At one year he had signs of psychomotor retardation and hypotonia. The magnetic resonance revealed frontal-temporal atrophy and a decrease in the corpus callosum. Testicular biopsy was compatible with gonadal dysgenesis. A preoperative cystography showed a vaginal remnant. Due to the presence of a sexual differentiation disorder, psychomotor retardation and facial dysmorphism, we requested a high-resolution karyotype: deletion 46, XY, del (9p) (p23-pter). Ish tel (9p-). Discussion: Many genes are involved in testicular differentiation, some of which also affect the development of other tissues. In the short arm of chromosome 9, two genes, DMRT1 and DMRT2, are involved in sexual differentiation. Their alterations have also been described as causing mental retardation. In the evaluation of 46,XY disorders of sex differentiation, the accompanying signs are very important for guiding the genetic study (AU)

[Chromosome 9P deletion: Gonadal dysgenesis associated with mental retardation and hypoplasia of the corpus callosum: A contiguous gene syndrome?]. / Deleción 9p-. Disgenesia gonadal asociada a retraso mental e hipoplasia del cuerpo calloso. ¿Síndrome de genes contiguos?

BACKGROUND: Many genes are involved in testicular differentiation. The alterations of these genes are responsible for sexual differentiation disorders with 46 XY karyotype. CASE: We report the case of a newborn who had an interscrotal hypospadias, palpable gonads and hypoplastic penis. Karyotype 46 XY. Abdominal ultrasound revealed testes and absence of Müllerian remnants. There was a good response to the short gonadotrophin test. At one year he had signs of psychomotor retardation and hypotonia. The magnetic resonance revealed frontal-temporal atrophy and a decrease in the corpus callosum. Testicular biopsy was compatible with gonadal dysgenesis. A preoperative cystography showed a vaginal remnant. Due to the presence of a sexual differentiation disorder, psychomotor retardation and facial dysmorphism, we requested a high-resolution karyotype: deletion 46, XY, del (9p) (p23-pter). Ish tel (9p-). DISCUSSION: Many genes are involved in testicular differentiation, some of which also affect the development of other tissues. In the short arm of chromosome 9, two genes, DMRT1 and DMRT2, are involved in sexual differentiation. Their alterations have also been described as causing mental retardation. In the evaluation of 46,XY disorders of sex differentiation, the accompanying signs are very important for guiding the genetic study.