A de novo interstitial deletion of chromosome 15 band q25 as revealed by FISH-technique.
We report a new chromosomal finding in a 20 month-old girl. The minor clinical features included: moderate mental retardation, microcephaly, mild hypotonia and hypertelorism. Initially, what appeared to be a terminal deletion of the long arm of one chromosome 15 [15q26-->qter] was determined to be an interstitial deletion involving band 15q25 as revealed by FISH-technique, showing the presence of intact telomeric hybridization signals. The cytogenetic diagnosis was thus modified to 46,XX, del (15) (pter-->q24::q26--> qter). Nevertheless, the function of the enzyme telomerase should not be ignored, as healing could occur following such terminal deletions. Consequently, it will remain a difficult task to distinguish terminal deletions from those that are interstitial.
Verma
R S
RS
Division of Genetics, Stanley S. Lamm Institute for Child Neurology and Developmental Medicine, Long island College Hospital-SUNY Health Science Center at Brooklyn, NY 11201, USA.
Kleyman
S M
SM
Giridharan
R
R
Ramesh
K H
KH
D002871:Chromosome Banding; D002872:Chromosome Deletion; D002884:Chromosomes, Human, Pair 15; D002658:Developmental Disabilities / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007621:Karyotyping