Chromosome disorders Weiying Jiang Department of Medical Genetics P33
What is chromosome? Chromosomes are complex structures located in the cell nucleus, they are composed of DNA, histone and non-histone proteins, RNA , and polysaccharides. They are basically the "packages" that contain the DNA.
A group——1 ～ 3 B group——4 ～ 5 C group——6 ～ 12 +X D group——13 ～ 15 E group——16 ～ 18 F group——19 ～ 20 G group——21 ～ 22 +Y Classification
Methods of chromosome analysis Karyotype analysis (G banding )
Methods of chromosome analysis Fluoresent in-situ hybridization (FISH) Utilizing fluorescently labeled DNA probes to detect or confirm gene or chromosome abnormalities that are generally beyond the resolution of routine Cytogenetics
Interphase FISH FISH can be used in interphase cells to determine the chromosome number of one or more chromosomes as well as to detect some specific chromosome rearrangements that are characteristic for certain cancers. The primary advantage of interphase FISH is that it can be performed very rapidly if necessary, usually within 24 hours, because cell growth is not required.