Sm. Kleyman et al., PARACENTRIC INVERSION INVOLVING THE LONG ARM OF CHROMOSOME-9 RESULTING IN DELETION OF ABL GENE, American journal of medical genetics, 68(4), 1997, pp. 409-411
We report on a new chromosomal finding in a newborn male with hypertel
orism, apparently low-set malformed ears with patent canal, micrognath
ia with narrow high-arched palate, bilateral webbing of neck with low
posterior hairline, widely spaced nipples, and complex heart anomalies
. Initially, what appeared to be a simple paracentric inversion of the
long arm of chromosome 9, that is, 46,XY, inv(9)(q31q34) by routine G
TG-banding technique was later determined to be a paracentric inversio
n with deletion of the band 9q34.1 by FISH technique using an abl uniq
ue sequence DNA probe. Thus the cytogenetic diagnosis was modified to
46,XY,der(9) inv(9)(q31q34.1)del(q34.1). Nevertheless, the presence of
telomeric repeat sequences in the inverted chromosome 9 suggests that
either healing has occurred by adding [TTAGGG](n) sequences to the no
ntelomeric end (q31) by the enzyme telomerase or telomeric sequences w
ere not affected during this inversion process. This abnormality is a
rare occurrence and has never been reported before either because of a
high rate of lethality or it has been undetected by routine cytogenet
ic techniques. The other abnormal cases with apparent paracentric inve
rsions could also have a complex nature with congenital anomalies asso
ciated with loss of ''few'' DNA sequences exemplified here. (C) 1997 W
iley-Liss, Inc.