A term widely used in clinical genetics encompassing the diverse techniques used to identify the molecular basis of genetic disease. Examples of molecular genetic tests include: genotyping to detect specific pathogenic variants; sequencing of a gene to detect pathogenic variants; amplification or hybridization methods (e.g., qPCR, array CGH, MLPA) to detect copy number variants involving one or more genes; methylation-specific techniques to detect epigenetic changes that influence gene expression; and exome and genome sequencing.