A dysmorphic boy with 4qter deletion and 4q32.3-34.3 duplication: clinical, cytogenetic, and molecular findings.
An infant boy presented with trigonocephaly, mild craniofacial features, a small VSD, open ductus Botalli (ODB), bilateral hip dysplasia, psychomotor retardation, and hypotonia. The karyotype was 46,XY,del(4)(q34). Unexpectedly, fluorescence in situ hybridization (FISH) studies revealed not only a deletion but also a duplication. The deletion extends from 4qter to 4q34.3 and the duplication from 4q32.3 to q34.3. This is the first description of a deletion inverted duplication 4q. Possible mechanisms we can envision by which this deletion/duplication arose could be a U-type exchange causing end-to-end fusion or a two step event with a paracentric inversion and subsequent cross-over in the inverted segment. This observation suggests that the karyotype of patients with a 4q deletion should be confirmed by molecular cytogenetics.
Van Buggenhout
Griet
G
Center for Human Genetics, University Hospital Leuven, Leuven, Belgium. griet.vanbuggenhout@uz.kuleuven.ac.be
Maas
Nicole M C
NM
Fryns
Jean-Pierre
JP
Vermeesch
Joris R
JR
D000015:Abnormalities, Multiple / Q000235:genetics*; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002894:Chromosomes, Human, Pair 4; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male