ABSTRACT
Chromosome 5p13 duplication syndrome represents a contiguous gene syndrome involving duplication of several genes on chromosome 5p13. Some clinical phenotypes are related to it, such as: obsessive-compulsive behavior, small palpebral fissures, intellectual disability, global development delay and ocular hypertelorism. The exact mechanism behind these changes has not well known and further studies are needed for this purpose. Since it is a rare and uncommon clinical situation, the case report contributes to the knowledge of the disease and early diagnosis. This condition mainly affects the cognitive neuromuscular system. We describe an 8-year-old Brazilian patient with the duplication of chromosome 5p13.2, karyotype, whose neurodevelopmental evaluation presented cognitive impairment, severe language delay and atypical physical examination, with ocular hypertelorism, right auricular tags, congenital heart defect and long fingers. The patient was diagnosed by comparative genomic hybridization (CGH)-array revealing a 204Kb of DNA duplication. The exact mechanism behind these structural disorders is still unclear and further studies are needed for this purpose. Nevertheless, the diagnostic suspicion of this genetic alteration that, in general, presents late diagnosis, should be considered to enable better clinical support to the patients and family genetic counseling.
A síndrome da duplicação do cromossomo 5p13 representa uma síndrome genética contígua envolvendo a duplicação de vários genes contidos nesta região. Alguns fenótipos clínicos estão relacionados com ela, tais como: comportamento obsessivo compulsivo, fissuras palpebrais pequenas, déficit intelectual, atraso no desenvolvimento global e hipertelorismo ocular. Por ser uma situação clínica rara, o relato do caso contribui para a disseminação do conhecimento acerca da condição, assim como para seu diagnóstico precoce. Descrevemos uma paciente brasileira de oito anos com a duplicação do cromossomo 5p13.2, que na avaliação do neurodesenvolvimento apresentou comprometimento cognitivo, grave atraso da linguagem e dismorfismos como hipertelorismo ocular, apêndice auricular direito, sopro cardíaco, relacionado a defeito do septo ventricular, e dedos alongados. A paciente foi diagnosticada por meio da pesquisa molecular (CGH)-array com ganho de 204Kb de DNA. O mecanismo exato por trás dessas alterações estruturais ainda não está claro e são necessários mais estudos para este fim. Não obstante, a suspeita diagnóstica dessa alteração genética que, em geral, apresenta diagnóstico tardio, deve ser aventada para viabilizar melhor suporte clínico aos pacientes e aconselhamento genético familiar.
Subject(s)
Humans , Female , Child , Segmental Duplications, Genomic , Chromosome Duplication/genetics , Genetic Testing/methods , Cognition Disorders/diagnosis , Failure to Thrive , Comparative Genomic Hybridization , Language Development Disorders/diagnosisABSTRACT
OBJECTIVE@#To explore the origin and mechanism of small supernumerary marker chromosomes (sSMC) in three fetuses.@*METHODS@#The three fetuses were predicted to have carried chromosomal abnormalities by non-invasive prenatal testing (NIPT). G-banding chromosomal karyotyping analysis were carried out on amniotic fluid samples of the fetuses and peripheral blood samples from their parents. Single nucleotide polymorphism array (SNP-array) was used to determine the origin, size and genetic effect of sSMCs.@*RESULTS@#In fetus 1, SNP array has detected two microduplications respectively at 4p16.3p15.2 (24.7 Mb) and 18p11.32q11.2 (20.5 Mb) which, as verified by fluorescence in situ hybridization (FISH), have derived from a balanced 46,XY,t(4;18)(p15.2q11.2) translocation carried by its father. Fetus 2 has carried a de novo microduplication of 15q11.2-q13.3 (9.7 Mb). The sequence of SMC in fetus 3 has derived from 21q11.2-q21.1 (8.3 Mb), which was inherited from its mother.@*CONCLUSION@#Both NIPT and SNP-array are highly accurate for the detection of sSMC. SNP-array can delineate the origin and size of abnormal chromosomes, which in turn can help with clarification of sSMC-related genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.
Subject(s)
Female , Humans , Male , Pregnancy , Chromosome Duplication/genetics , Fetus , In Situ Hybridization, Fluorescence , Polymorphism, Single Nucleotide , Prenatal Diagnosis , Translocation, Genetic/geneticsABSTRACT
Background: Congenital heart defects (CHD) are the most prevalent group of structural abnormalities at birth and one of the main causes of infant morbidity and mortality. Studies have shown a contribution of the copy number variation in the genesis of cardiac malformations. Objectives: Investigate gene copy number variation (CNV) in children with conotruncal heart defect. Methods: Multiplex ligation-dependent probe amplification (MLPA) was performed in 39 patients with conotruncal heart defect. Clinical and laboratory assessments were conducted in all patients. The parents of the probands who presented abnormal findings were also investigated. Results: Gene copy number variation was detected in 7/39 patients: 22q11.2 deletion, 22q11.2 duplication, 15q11.2 duplication, 20p12.2 duplication, 19p deletion, 15q and 8p23.2 duplication with 10p12.31 duplication. The clinical characteristics were consistent with those reported in the literature associated with the encountered microdeletion/microduplication. None of these changes was inherited from the parents. Conclusions: Our results demonstrate that the technique of MLPA is useful in the investigation of microdeletions and microduplications in conotruncal congenital heart defects. Early diagnosis of the copy number variation in patients with congenital heart defect assists in the prevention of morbidity and decreased mortality in these patients. .
Fundamento: Os defeitos cardíacos congênitos são o grupo de anormalidades estruturais mais prevalentes ao nascimento e uma das principais causas de morbidade e mortalidade infantil. Estudos têm mostrado a contribuição da variação no número de cópias na gênese das malformações cardíacas. Objetivos: Investigar a variação no número de cópias gênicas em crianças com defeito cardíaco conotruncal. Métodos: Multiplex Ligation-dependent Probe Amplification (MLPA) foi realizado em 39 pacientes com defeito cardíaco conotruncal. Avaliação clínica e laboratorial foi realizada em todos os pacientes. Os pais dos probandos que apresentaram alterações também foram investigados. Resultados: Variação no número de cópias foi detectada em 7/39 pacientes: deleção 22q11.2, duplicação 22q11.2, duplicação 15q11.2, duplicação 20p12.2, deleção 19p, duplicação 15q e 8p23.2 com duplicação 10p12.31. As características clínicas foram compatíveis com o relatado na literatura associadas com microdeleção/microduplicação encontrada. Nenhuma dessas alterações foi herdada dos pais. Conclusões: Nossos resultados demonstram que a técnica de MLPA é útil na investigação de microdeleções e microduplicações em defeitos cardíacos congênitos conotruncais. O diagnóstico precoce das variações no número de cópias em pacientes com defeito cardíaco congênito auxilia na prevenção de morbidade e diminuição da mortalidade nesses pacientes. .
Subject(s)
Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Chromosome Deletion , Chromosome Duplication/genetics , DNA Copy Number Variations/genetics , Heart Defects, Congenital/genetics , /genetics , Early Diagnosis , Genetic Association Studies , Heart Defects, Congenital/pathology , Heart Defects, Congenital/physiopathology , Heart Septal Defects, Ventricular/genetics , Multiplex Polymerase Chain Reaction , Prospective StudiesABSTRACT
La trisomía parcial 4q es una enfermedad cromosómica rara causada por la duplicación de una porción (comúnmente la distal) del brazo largo del cromosoma 4. En la mayoría de los casos resulta de una translocación balanceada de uno de los progenitores, siendo menos frecuente la aparición de novo. Los pacientes presentan diversas características clínicas según el tamaño y sitio específico de la región comprometida. Su asociación con patologías oculares ha sido escasamente comunicada. Presentamos el primer caso de un paciente pediátrico de sexo masculino con una duplicación parcial de novo del segmento proximal del brazo largo del cromosoma 4 (4q12-q22) y coloboma bilateral de iris, retina y nervio óptico.
Partial trisomy 4q is a rare chromosomal disease. It involves duplication of a portion (particularly the distal one) of the long arm of chromosome 4. In most cases results from a balanced translocation on one single progenitor. The "de novo" appearance is less common. Depending on the size and location of duplicated genetic material, patients may have different clinical manifestations. Associated eye pathology has been scarcely informed. We report on a novel case of a male infant with a proximal "de novo" 4q12-q22 duplication and bilateral iris, retinal and optic nerve coloboma.