Cryptic trisomy 5q35.2qter and deletion 1p36.3 characterised using FISH and array-based CGH.
A 10(6/12)-year-old boy was referred to the genetics department because of mental retardation and dysmorphic findings including microcephaly, flat face, down-slanting palpebral fissures, strabismus, prominent ears, bulbous nasal tip, down-turned corners of the mouth, narrow palate, clinodactyly of the fifth fingers and generalised eczema. Cytogenetic analysis revealed a karyotype of 47,XY,+mar of paternal origin. Multicolour FISH showed the marker chromosome to be derived from chromosome 15. For further elucidation of the phenotype, array-based comparative genomic hybridisation (aCGH) was performed, which revealed dup(5)(q35.2qter) and del(1)(p36.3). Parental FISH analysis revealed that the translocation occurred de novo. Despite the presence of a clinical phenotype along with a microscopically visible chromosomal aberration, a complex cryptic cytogenetic abnormality was causative for the phenotype of the patient. Elucidation of this complex aberration required combination of the whole cytogenetic toolbox.
Utine
Eda G
EG
Clinical Genetics Unit, Department of Pediatrics, Hacettepe University, Ankara, Turkey. geutine@hacettepe.edu.tr
Alanay
Yasemin
Y
Aktas
Dilek
D
Alikasifoglu
Mehmet
M
Boduroglu
Koray
K
Vermeesch
Joris
J
Tuncbilek
Ergul
E
Fryns
Jean-Pierre
JP
D000328:Adult; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D002658:Developmental Disabilities / Q000235:genetics / Q000473:pathology; D015894:Genome, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D014314:Trisomy / Q000235:genetics*