Isocromosomas X: diagnóstico tardío de síndrome de Turner / X Isochromosomes: Delayed diagnosis of Turner's syndrome

El síndrome de Turner se diagnostica mediante la combinación de ciertas características fenotípicas con la ausencia de un cromosoma X. Esta ausencia puede ser total o parcial, como la que tiene lugar en los isocromosomas X. Las consecuencias fenotípicas de estos dependen de 2 factores: la naturaleza de los genes que se han perdido y el porcentaje de células 45, X en los mosaicismos. La clínica cambia en función del patrón citogenético, prevaleciendo la talla baja como manifestación fenotípica, ya que radica en la haploinsuficiencia del gen SHOX en el brazo corto del cromosoma X. Así, cuando existen isocromosomas de los brazos largos, la talla baja siempre está presente. Sin embargo, los rasgos típicos pueden estar ausentes, conllevando retraso diagnóstico. Este hecho se da en nuestras pacientes, y a causa de ello se beneficiarán en menor medida del tratamiento con GH

Turner syndrome is diagnosed by the combination of certain phenotypic characteristics with the absence of one of the X chromosome. This absence may be total or partial, as occurs in isochromosomes Xq. The phenotypic consequences of these depend on two factors: the characteristics of the lost genes and the percentage of cells 45, X in mosaicisms. The clinical features also change with the cytogenetic pattern. Short stature is the most common phenotypic manifestation, as it is due to the haploinsufficiency of the SHOX gene on the short arm of X chromosomes. Thus, when there is isochromosomes on the long arms, short stature is always present. However, the typical features of this syndrome could be absent, and the diagnosis can be delayed. This occurred in our patients, who will not be able to obtain optimum benefits with growth hormone treatment

[X isochromosomes: delayed diagnosis of Turner's syndrome]. / Isocromosomas X: diagnóstico tardío de síndrome de Turner.

Turner syndrome is diagnosed by the combination of certain phenotypic characteristics with the absence of one of the X chromosome. This absence may be total or partial, as occurs in isochromosomes Xq. The phenotypic consequences of these depend on two factors: the characteristics of the lost genes and the percentage of cells 45, X in mosaicisms. The clinical features also change with the cytogenetic pattern. Short stature is the most common phenotypic manifestation, as it is due to the haploinsufficiency of the SHOX gene on the short arm of X chromosomes. Thus, when there is isochromosomes on the long arms, short stature is always present. However, the typical features of this syndrome could be absent, and the diagnosis can be delayed. This occurred in our patients, who will not be able to obtain optimum benefits with growth hormone treatment.