Clinical cytogenetics is a medical specialty that studies chromosomal abnormalities and genetic disorders in humans. Chromosomes are molecules of DNA that dictate an individual's genetic makeup and clinical cytogeneticists use advanced laboratory equipment to identify irregular chromosome structures. These chromosomal differences may result in genetic disease, which can include some developmental disorders and congenital malformations. Clinical cytogenetic testing may also reveal certain oncological (cancer) or hematological (blood) diseases.
Patients can be tested at any age, whether or not they are suspected to possess a genetic disorder. Even before birth, clinical cytogeneticists may perform prenatal tests on amniotic fluid (fluid surrounding a fetus) to determine if an infant carries a chromosomal abnormality. Clinical cytogeneticists may evaluate the patient samples from:
Specimens are collected and submitted by patients' physicians and tested by clinical cytogeneticists. One such test is fluorescence in situ hybridization (FISH), which allows cytogeneticists to analyze genetic fragments and certain chromosomal changes. Another cytogenetic test called microarray assay, or DNA microarray, can scan an entire genome and may detect developmental disorders. Comparative genomic hybridization (CGH) tests may also assess a whole genome. CGH uses computer technology to locate markers of cancer, rare diseases, and other illnesses.
Clinical cytogeneticists may collaborate with molecular genetic pathologists, anatomic pathologists, oncologists, hematologists, and a number of other medical specialists. Clinical cytogeneticists are physicians with additional cytogenetic training, or health professionals who possess a PhD in genetics and complete additional cytogenetic training.