American College of Medical Genetics guideline on the cytogenetic evaluation of the individual with developmental delay or mental retardation

Abstract

The following are the recommendations of the American College of Medical Genetics (ACMG) Professional Practice and Guidelines Committee, which was convened to assist health care professionals in making decisions regarding cytogenetic diagnostic testing and counseling for mental retardation (MR) and developmental delay (DD). This document reviews available evidence concerning the value of conventional and molecular cytogenetic testing for the identification of chromosomal anomalies that play a role in the etiology of MR/DD, and, based on this evidence, specific recommendations for each method of testing are provided.

Diagnóstico citogenético de pacientes com retardo mental idiopático

“…O cariótipo com bandeamento G é o exame citogenético inicial indicado para pacientes com suspeita de rearranjos cromossômicos (36) . Os cromossomos metafásicos dos pacientes são analisados com resolução de 400 a 550 bandas.…”

“…O RM manifesta-se antes dos 18 anos e não pode ser diagnosticado antes de a criança completar 5 anos, quando as medidas de inteligência são confiáveis para se aplicar o teste de QI. Para crianças com menos de 5 anos, o termo atraso de desenvolvimento neuropsicomotor (ADNPM) é usualmente utilizado (36) .…”

Array-based comparative genomic hybridization: clinical contexts for targeted and whole-genome designs

“…13 These patients often demonstrate mental retardation as they grow, and many suffer from congenital anomalies. Conventional subtelomere-targeted FISH detects cytogenetic imbalances in about 2.5% of these patients.…”

Downsizing genomic medicine: Approaching the ethical complexity of whole-genome sequencing by starting small

“…[17][18][19] Although it may not be possible to counsel patients about technical features of each individual assay included on such an array, the medical rationale for recommending testing and the potential clinical implications of various test results can be reviewed in detail with patients before seeking informed consent to genetic testing. 20 Among multiplexed genotyping arrays, there can be multiple approaches. Perhaps the most conservative approach is to evaluate only well-characterized mutations that are known to be strongly associated with Mendelian diseases.…”