Chapter 7
FISH on Hair Root Cells
THOMAS LIEHR
Introduction
In clinical cytogenetics, patients with somatic chromosomal mosaicism
are present in about 0.3 to 1% of analyzed cases. Mosaic karyotypes in
connection with gonosomes are the most frequent observation, presenting
e.g. with karyotypes like 4S,x[1O]l47,XXX[S]/46,XX[S] (unpublished case
of an unfertile woman, Inst. of Human Genetics, Jena). However, autosomes can be involved, as well, as in a familial case with a supernumerary
marker derived from chromosome 8, present in the peripheral blood ofthe
father in 10% and in that of the two daughters in 97 and 98% of analyzed
metaphase spreads (Rothenmund et al., 1997). Such kinds of mosaicism
can easily be detected by interphase FISH using centromere-specific or
locus-specific probes of the corresponding chromosomes.
As it is a well-known fact that the patterns of mosaicism can vary to a
great extent in different kinds of tissues of the same patient (e.g. Pfeiffer
and Schulze, 1994), the analysis of different tissue types by molecular cytogenetic methods can be of great interest. This has been demonstrated
with the example of a patient with a microdupiication on chromosome
17p11.2, which appeared in different patterns of mosaicism in peripheral
blood [49%], in buccal mucosa [SI%], in nerve tissue [74%] and in hair
root cells [66%] (Liehr et al., 1996).
In the following, a modified protocol according to Lampel et al. (1993)
for pretreating hair root cells before FISH is described. It may be useful for
the analyses of mosaic cases as well as in cases where other types of cells
are difficult to obtain.
~ Thomas Liehr, Institut fur Humangenetik, Kollegiengasse 10, Jena, 07743, Germany
(phone +49-3641-935533; fax +49-3641-935502; e-mail i8Iith@mti-n.mti.uni-jena.de)
PROTOCOL
FISH on Hair Root Cells
THOMAS LIEHR
Introduction
In clinical cytogenetics, patients with somatic chromosomal mosaicism
are present in about 0.3 to 1% of analyzed cases. Mosaic karyotypes in
connection with gonosomes are the most frequent observation, presenting
e.g. with karyotypes like 4S,x[1O]l47,XXX[S]/46,XX[S] (unpublished case
of an unfertile woman, Inst. of Human Genetics, Jena). However, autosomes can be involved, as well, as in a familial case with a supernumerary
marker derived from chromosome 8, present in the peripheral blood ofthe
father in 10% and in that of the two daughters in 97 and 98% of analyzed
metaphase spreads (Rothenmund et al., 1997). Such kinds of mosaicism
can easily be detected by interphase FISH using centromere-specific or
locus-specific probes of the corresponding chromosomes.
As it is a well-known fact that the patterns of mosaicism can vary to a
great extent in different kinds of tissues of the same patient (e.g. Pfeiffer
and Schulze, 1994), the analysis of different tissue types by molecular cytogenetic methods can be of great interest. This has been demonstrated
with the example of a patient with a microdupiication on chromosome
17p11.2, which appeared in different patterns of mosaicism in peripheral
blood [49%], in buccal mucosa [SI%], in nerve tissue [74%] and in hair
root cells [66%] (Liehr et al., 1996).
In the following, a modified protocol according to Lampel et al. (1993)
for pretreating hair root cells before FISH is described. It may be useful for
the analyses of mosaic cases as well as in cases where other types of cells
are difficult to obtain.
~ Thomas Liehr, Institut fur Humangenetik, Kollegiengasse 10, Jena, 07743, Germany
(phone +49-3641-935533; fax +49-3641-935502; e-mail i8Iith@mti-n.mti.uni-jena.de)
PROTOCOL