ABSTRACT
Partial trisomy 15q is a very rare entity and most of them are characterized by duplication of regions 15q21-15q26.3. This duplication is frequently associated with deletions in another chromosome resulting in unbalanced translocations. Authors report here, a rare case of partial trisomy 15, with breakpoints between 15q11.1 to q23, probably the first reported case with these breakpoints. Irrespective of the breakpoints, the phenotypic features are consistent in all affected cases and predominantly consist of craniofacial anomalies. In addition, finger abnormalities, very short neck, skeletal malformations and congenital heart disease may be present. Our neonate had typical dysmorphic features of arachnocamptodactyly, narrow face, large prominent, nose with broad nasal bridge, long philtrum, pointed chin, short neck, and low set deformed ears.' Neonates' cytogenetic analysis revealed additional chromosomal material on the long arm of the chromosome 15 from q11.1 to q23.1, which was suggestive of partial trisomy of chromosome 15. Most cases reported have had a stormy clinical course, however, our proband had only mild respiratory distress at birth and she was discharged in a few days.
ABSTRACT
Distal duplication, or trisomy 15q, is an extremely rare chromosomal disorder characterized by prenatal and postnatal overgrowth, mental retardation, and craniofacial malformations. Additional abnormalities typically include an unusually short neck, malformations of the fingers and toes, scoliosis and skeletal malformations, genital abnormalities, particularly in affected males, and, in some cases, cardiac defects. The range and severity of symptoms and physical findings may vary from case to case, depending upon the length and location of the duplicated portion of chromosome 15q. Most reported cases of duplication of the long arm of chromosome 15 frequently have more than one segmental imbalance resulting from unbalanced translocations involving chromosome 15 and deletions in another chromosome, as well as other structural chromosomal abnormalities. We report a female newborn with a de novo duplication, 15q24-q26.3, showing intrauterine overgrowth, a narrow asymmetric face with down-slanting palpebral fissures, a large, prominent nose, and micrognathia, arachnodactyly, camptodactyly, congenital heart disease, hydronephrosis, and hydroureter. Chromosomal analysis showed a 46,XX,inv(9)(p12q13),dup(15)(q24q26.3). Array comparative genomic hybridization analysis revealed a gain of 42 clones on 15q24-q26.3. This case represents the only reported patient with a de novo 15q24-q26.3 duplication that did not result from an unbalanced translocation and did not have a concomitant monosomic component in Korea.