[Mosaic trisomy 9: report of a new case with a long-term survival]. / Mosaicismo de trisomía 9: caso de larga supervivencia.

INTRODUCTION: Trisomy 9 is an uncommon chromosome abnormality that may be seen in a mosaic or non-mosaic state. OBJECTIVE: To better define the phenotype and prognosis of this disorder we report a new case of mosaic trisomy 9 with a long-term survival. CLINICAL REPORT: We present the case of a female patient, born from the first pregnancy of a healthy couple. Fetal ultrasounds disclosed intrauterine growth retardation and oligohydramnios. Cesarean section was performed in the 34th week. Birth weight was 1,478 g. Neonatal examination showed: dolichocephaly; hypotelorism, microphthalmia, short palpebral fissures; broad-based nose with bulbous tip; micrognathia; low-set malformed ears; abnormal hands and feet; no other malformations. The initial karyotype determination was normal (46,XX). At 17 months of age, a second karyotype was requested because the patient developed severe psychomotor retardation. Chromosome analysis showed mosaic trisomy 9 (46,XX/47,XX, + 9). Six months later, a single upper central incisor was noted. To our knowledge, this feature has not been reported previously in the trisomy 9. The patient is now 4 years old. She shows severe psychomotor retardation, but no other complications. COMMENTS: It is important to be aware of the possibility that mosaicism may exist in a patient with normal blood karyotype and abnormal phenotype. We conclude that a great number of cells is needed in order to obtain a correct karyotype diagnosis. Correct diagnosis is essential to define the prognosis and provide accurate genetic counselling.

Mosaicismo de trisomía 9: caso de larga supervivencia / Mosaic trisomy 9: report of a new case with a long-term survival

Introducción: La trisomía 9 es una aneuploidía infrecuente y, por tanto, difícil de sospechar. Objetivo: Comunicar un nuevo caso de mosaicismo de trisomía 9, de larga supervivencia, para contribuir al mejor conocimiento de sus características clínicas y pronóstico. Caso clínico: Primera hija de padres sanos. Retraso de crecimiento intrauterino asimétrico y oligohidramnios. Nace a las 34 semanas con 1.478 g de peso, depresión respiratoria y fenotipo anómalo: dolicocefalia; hipotelorismo, microftalmia, hendiduras palpebrales pequeñas; nariz de base ancha y punta en bulbo; micrognatia; orejas de implantación baja, y anomalías en las manos y los pies. Ausencia de malformaciones en los órganos internos. Cariotipo: normal (46,XX). A los 17 meses, ante el retraso psicomotor evidente y las alteraciones descritas se realiza un segundo cariotipo convencional insistiendo en el análisis de un mayor número de células. Se halla un mosaicismo de trisomía 9 (46,XX/47,XX, 1 9). Como dato fenotípico curioso, a los 24 meses aparece un incisivo único superior medial, no descrito antes en otros casos de trisomía 9. Actualmente, tiene 4 años, un retraso mental profundo y ninguna otra complicación. Comentarios: Destaca la mayor dificultad diagnóstica de los mosaicismos; por lo que se debe insistir en el análisis de un número suficiente de células al estudiar el cariotipo. Además, es importante su diagnóstico en sujetos con anomalías fenotípicas, para dar información correcta a los padres en orden a su pronóstico y a la futura descendencia (AU)

Introduction: Trisomy 9 is an uncommon chromosome abnormality that may be seen in a mosaic or non-mosaic state. Objective: To better define the phenotype and prognosis of this disorder we report a new case of mosaic trisomy 9 with a long-term survival. Clinical report: We present the case of a female patient, born from the first pregnancy of a healthy couple. Fetal ultrasounds disclosed intrauterine growth retardation and oligohydramnios. Cesarean section was performed in the 34th week. Birth weight was 1,478 g. Neonatal examination showed: dolichocephaly; hypotelorism, microphthalmia, short palpebral fissures; broad-based nose with bulbous tip; micrognathia; low-set malformed ears; abnormal hands and feet; no other malformations. The initial karyotype determination was normal (46,XX). At 17 months of age, a second karyotype was requested because the patient developed severe psychomotor retardation. Chromosome analysis showed mosaic trisomy 9 (46,XX/47,XX, 1 9). Six months later, a single upper central incisor was noted. To our knowledge, this feature has not been reported previously in the trisomy 9. The patient is now 4 years old. She shows severe psychomotor retardation, but no other complications. Comments: It is important to be aware of the possibility that mosaicism may exist in a patient with normal blood karyotype and abnormal phenotype. We conclude that a great number of cells is needed in order to obtain a correct karyotype diagnosis. Correct diagnosis is essential to define the prognosis and provide accurate genetic counseling (AU)