A cryptic unbalanced translocation t(2;9)(p25.2;q34.3) causes the phenotype of 9q subtelomeric deletion syndrome and additional exophthalmos and joint contractures.
We report on a 26-year-old woman with microcephaly, typical facial features of 9q subtelomeric deletion syndrome, exophthalmos, contractures of elbow and knee joints, severe muscular hypotonia, no ability to walk, and no speech development. Array CGH revealed a cryptic 9q34.3 deletion and 2p25.2-p25.3 duplication transmitted by her mother, who was carrying a balanced translocation of chromosomes 2p and 9q. There are about 50 reported cases of deletions of the subtelomeric part of chromosome 9q, however, duplications of only the terminal part of chromosome 2p are rare. Neuroblastoma, diaphragmatic hernia, neural tube defects, broncho-pulmonary abnormalities, and congenital heart defects are conditions associated with partial trisomy of larger fragments of 2p. To our knowledge there is only one case described with an isolated duplication as distal as in the patient reported here. Joint contractures and exophthalmos observed in this patient are also seen in our patient. These features are not allegeable by the deletion 9q34.3 identified in the patient reported here and may be a hint that terminal duplication of 2p could be associated with exophthalmos and contractures.
Busche
Andreas
A
Charité-Universitätsmedizin Berlin, Institute of Medical Genetics, Berlin, Germany. andreas.busche@charite.de
Klopocki
Eva
E
Ullmann
Reinhard
R
Mundlos
Stefan
S
Horn
Denise
D
D000328:Adult; D002872:Chromosome Deletion; D002889:Chromosomes, Human, Pair 2; D002899:Chromosomes, Human, Pair 9; D003286:Contracture / Q000235:genetics*; D005094:Exophthalmos / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D010641:Phenotype; D014178:Translocation, Genetic