Trisomía 9p: Una breve descripción clínica, diagnóstica y terapéutica / Trisomy 9p: A brief clinical, diagnostic and therapeutic description

La trisomía del 9p se caracteriza por la duplicación de todo o de algún segmento del brazo corto del cromosoma 9. Es una de las anomalías autosómicas estructurales más frecuentes en recién nacidos. Esta región es relativamente pobre en genes, por lo que puede ser más compatible con la supervivencia. Se caracteriza por presentar retraso del crecimiento, psicomotor y mental, dismorfias cráneo-faciales, alteraciones esqueléticas, así como anomalías en el sistema nervioso central, cardiopatías congénitas y alteraciones renales en menor frecuencia. Para realizar el diagnóstico, debe desarrollarse el estudio citogenético mediante la técnica de banda G, y, si está disponible, se recomienda la hibridación por fluorescencia in situ, complementada por la hibridación genómica comparativa, para la mejor comprensión de la correlación genotipo-fenotipo. La evaluación debe ser interdisciplinaria, en la que se incluya un oportuno asesoramiento genético familiar y, con ello, las opciones terapéuticas disponibles y de forma precoz.

Trisomy 9p is characterized by the partial or complete duplication of the short arm of chromosome 9. It is one of the most common autosomal structural abnormalities in newborn infants. This is a relatively poor gene region, so it may be more compatible with survival. It is characterized by delayed mental and psychomotor growth, craniofacial dysmorphisms, skeletal alterations, central nervous system abnormalities, congenital heart disease, and, to a lesser extent, kidney disorders. To establish a diagnosis, it is necessary to perform a cytogenetic study with G bands and, if available, fluorescence in situ hybridization complemented with comparative genomic hybridization for a better understanding of the genotype-phenotype correlation. Assessment should be interdisciplinary and encompassing a timely family genetic counseling, together with available therapeutic options in an early manner.

Manifestaciones fenotípicas de un caso con sospecha clínica de trisomía parcial del cromosoma 9p / Phenotypical manifestations of a case with clinical suspicious of partial trisomy of chromosome 9p

Fundamento: Las anomalías cromosómicas pueden ser numéricas o estructurales, esta última puede producirse por duplicación parcial o total de un cromosoma, como se describe en la trisomía parcial 9p. Los afectados por esta cromosopatía, se caracterizan por hipotonía, discapacidad intelectual, retraso sicomotor, malformaciones craneofaciales distintivas, anomalías de manos y pies Objetivo: Ilustrar debido a su rareza un caso de cromosopatía. Presentación de caso: Se describen las manifestaciones fenotípicas de un niño de dos años, con diagnóstico clínico, de una trisomía parcial 9p, con un cariotipo no balanceado definido por la siguiente fórmula: 47,XY+(mar). Conclusiones: Se concluyen con los estudios realizados que este paciente presenta una trisomía de novo en línea pura; aún sin diagnóstico confirmado por estudio molecular por hibridación in situ fluorescente (FISH), fue necesario el diagnóstico clínico precoz para intervención temprana y brindar asesoramiento genético a la familia.

Background: Chromosome anomalies can be either numeric or structural; this last one can be reproduced by partial or total duplication of a chromosome, as described in the trisomy of chromosome 9p. The ones affected by this chromosopathy are characterized by hypotonia, intellectual incapacity, psychomotor retardation, distinctive craniofacial malformations and foot and hands anomalies. Objective: To illustrate, due to it’s a case of chromosopathy. Case presentation: There are described the phenotypical manifestations of a two-year-old child with clinical diagnosis of partial trisomy 9p with a non balanced karyotype defined by the formula: 47,XY+(mar). Conclusion: This patient is suffering from a novo trisomy in pure line; having non confirmed diagnosis by molecular study by fluorescent hybridation in situ (FISH), it was necessary the early clinical diagnosis for early intervention and for giving genetic upgrading to the family.

Diagnosis of an uncertain karyotype and mentally retarded child using the whole genome microarray scanning technique / 临床儿科杂志

Objective To investigate the possibility and feasibility of the whole genome microarray scanning technique in clinical cytogenetic diagnosis of an uncertain karyotype and mentally retarded child. Methods The karyotype analysis of the mental development delayed child was 47, XY+mar. Genomic DNA was extracted from the peripheral blood and the whole genome microarray scanning technique was used to analyze the derivative chromosome. Results The whole genome microar-ray scanning technique indicated the derivative chromosome fragment had originated from 9p13.1-p24.3. Conclusions Com-paring to conventional cytogenetic analysis methods, the whole genome microarray scanning technique is of high resolution, high-throughput and high accuracy, which can detect the submicroscopic chromosomal aberrations and replace the conven-tional karyotype analysis.

A Case of Partial Trisomy 9pter --> q13 due to Paternal Balanced Translocation t (9;21) (q13;q21) / 대한진단검사의학회지

Trisomy 9p is one of the most frequent autosomal anomalies compatible with a long survival rate. Clinical characteristics are craniofacial dysmorphisms including hypertelorism, prominent nose, deepset eyes, and down-slanting palpebral fissures. The degree of clinical severity in trisomy 9 roughly correlates with the extent of trisomic chromosomal material. If the trisomic segments include the long arm of chromosome 9, clinical findings may not fit into the trisomy 9p but rather resemble trisomy 9 mosaic syndrome and are associated with muscular and cardiac anomalies. Therefore, breakpoints as well as clinical findings need to be precisely defined for differential diagnosis. Cases with trisomy 9p, especially involving proximal 9q, are very rare in Korea. The patient was a 1,920 g male infant born at 36 weeks 3 days of gestation to a 27-yr-old mother and 32-yr-old father after Cesarian section. The patient showed specific craniofacial anomalies, cardiac defects, and hand anomalies. Routine cytogenetic analysis, performed on peripheral blood using GTG banding, showed 46,XY,+der(9)t (9;21)(q13;q21),-21pat. Furthermore, FISH (Vysis Inc., USA) analysis with whole chromosome painting probes confirmed the derivative chromosome 9.

Dandy-Walker malformations in a case of partial trisomy 9p (p12.1→pter) due to maternal translocation t(9;12)(p12.1;p13.3).

We describe a five-year-old proband presented with Dandy-Walker malformations, right microopthalmia, hamstring contractures, undescended testis with absence of testis in right scrotum in addition to typical trisomy 9p clinical features. Routine cytogenetic studies with GTG - banding showed 46,XY,der(12)t(9;12) (p12;q13.3),mat karyotype (trisomy 9p). Chromosomal analysis of the father was normal and phenotypically normal mother had 46,XX,t(9;12)(p12;q13) karyotype. Fluorescence in situ hybridization analysis with single copy probes bA5OIA2 (9p11.2), bA562M8 (12p12.1) and centromere probes (9) showed break point at 9p12.1 region. The gene dosage effect of Chromosome 9p along with environmental factors might be associated with Dandy- Walker malformations in the patient.

A Case of Partial Trisomy 9p Syndrome with 3-Ketothiolase Deficiency / 대한소아신경학회지

Trisomy 9p syndrome was first described by Rethore et al in 1970 and about 150 cases have been reported. The characteristic features of the partial trisomy 9p syndrome is clearly recognizable faces, which include microcephaly, facial deformities, skeletal and dermatoglyphic anomalies with variable degrees of mental retardation. The 3-ketothiolase deficiency was first described in 1971 and about 30 cases have been reported. The 3-ketothiolase deficeiency is an inborn error of isoleucine and ketone body catabolism that shows autosomal recessive traits, caused by a deficiency of mitochondrial acetoacetyl-coenzyme A thiolase(T2). We report a case of partial trisomy 9p syndrome with 3-ketothiolase deficeiency in a 4-years-old female. The karyotype of the patient was confirmed as 46,XY, add(9)(p23) mat. In the urine organic acid test, 3-ketothiolase deficiency was reported.