Abstract:

In order to assess the value of applying human chromosomal telomeric band painting probes (TBPs) in genetic diagnosis, we used three human telomeric band painting probes in fluorescence in situ hybridization（FISH）to analyze two cases who had a history of habitual abortion and were suspected to carrying a minute translocation. The probes were prepared by microdissection, and the covered regions were 11q23.3→qter，12q24.1→qter and 22q13.1→qter, respectively. According to the FISH results, both the cases were cryptic minute translocation carriers. The involved chromosomes were chromosome 11 and 12 in case 1, and chromosome 11 and 22 in case 2. Combined with chromosome G banding, their breakpoints were 11q23.3, 12q24.1, and 22q13.1, respectively. The results showed that the telomeric band painting probes can be used as a tool to determine minute chromosomal abnormality and the precise breakpoints.

Key words: telomeric band painting probes (TBPs), FISH, minute translocation, recurrent spontaneous abortion, carrier