Diagnosis of four chromosome abnormalities of unknown origin by chromosome microdissection and subsequent reverse and forward painting.
A molecular cytogenetic method consisting of chromosome microdissection and subsequent reverse/forward chromosome painting is a powerful tool to identify chromosome abnormalities of unknown origin. We present 4 cases of chromosome structural abnormalities whose origins were ascertained by this method. In one MCA/MR patient with an add(5q)chromosome, fluorescence in situ hybridization (FISH), using probes generated from a microdissected additional segment of the add(5q) chromosome and then from a distal region of normal chromosome 5, confirmed that the patient had a tandem duplication for a 5q35-qter segment. Similarly, we ascertained that an additional segment of an add(3p) chromosome in another MCA/MR patient had been derived from a 7q32-qter segment. In a woman with a history of successive spontaneous abortions and with a minute marker chromosome, painting using microdissected probes from the whole marker chromosome revealed that it was i(15)(p10) or psu dic(15;15)(q11;q11). Likewise, a marker observed in a fetus was a ring chromosome derived from the paracentromeric region of chromosome 19. We emphasize the value of the microdissection-based chromosome painting method in the identification of unknown chromosomes, especially for marker chromosomes. The method may contribute to a collection of data among patients with similar or identical chromosome abnormalities, which may lead to a better clinical syndrome delineation.
Coêlho
K E
KE
Department of Human Genetics, Nagasaki University School of Medicine, Japan.
Egashira
M
M
Kato
R
R
Fujimoto
M
M
Matsumoto
N
N
Rerkamnuaychoke
B
B
Abe
K
K
Harada
N
N
Ohashi
H
H
Fukushima
Y
Y
Niikawa
N
N
D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D001483:Base Sequence; D015193:Chorionic Villi Sampling; D002869:Chromosome Aberrations / Q000175:diagnosis* / Q000235:genetics*; D002871:Chromosome Banding / Q000379:methods*; D025063:Chromosome Disorders; D002888:Chromosomes, Human, Pair 19; D002895:Chromosomes, Human, Pair 5; D002897:Chromosomes, Human, Pair 7; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics; D007621:Karyotyping; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D014314:Trisomy