Cyto + Sequence Nomenclature

Lab Foundations

cytogenetic nomenclature is used to:

describe results of cyto testing, assess structure and arrangement of chromosomes, karyotype, ch microarray, assess larger lesions that may include a single gene to many genes as a part or whole chs

molecular nomenclature is used to:

describe results of molecular testing, assess sequence and structure of individual genes, detect copy numbers, targeted assessment of a single gene, panel, exome, and genome sequencing

11q23.1

eleven q two three point one

mosaicism

individual has 2 or more chromosomally different sets of cells in body, normal cell line listed last, if several cell lines largest abnormal first

balanced structural rearrangement

often no phenotype, but risk to transmit in unbalanced manner

unbalanced structural rearrangement

loss and/or gain of material, phenotype dependent on content and amnt

robertsonian translocation

involves 2 acrocentric chs, balanced and has 45 total chs

inversion

ch broken, flipped, and reinserted

pericentric inversion

includes centromere (ex: 46, XX, inv (1) (p25q22))

paracentric inversion

doesn’t include centromere (ex: 46, XX, inv (1) (p25q22))

FISH

uses fluorescently labeled DNA probes to detect, enumerate, and characterize ch abnormalities