Background
Partial trisomy of the short arm of chromosome 9 is among the most common autosomal anomalies, leading to specific clinical characteristics including intellectual disability, short stature, craniofacial dysmorphism, and digital anomalies. Typical clinical features of 14q terminal deletion syndrome include intellectual disability, microcephaly, postnatal growth retardation, muscular hypotonia, and dysmorphic features.
Patient and aim
In this study, we report on a 7.5-year-old female patient with de novo trisomy 9p and deletion of 14q32.3 presented with delayed motor and mental milestones, dysmorphic features, microcephaly, short stature, and hypotonia. The aim of this study was to delineate breakpoints and identify the genotype/phenotype correlations.
Methods and results
The chromosomal abnormalities in the patient were characterized by G-banding, fluorescent in-situ hybridization (FISH), multiple ligation probe amplification, and array CGH. Karyotype showed 46, XX, add (14)(q32.3). FISH revealed deletion of 14q subtelomere and duplication of 9p subtelomere. Multiple ligation probe amplification detected 9p subtelomere trisomy. Array CGH identified 34 Mb duplication of chromosome 9p and 378 kb deletion of chromosome 14q32.3.
Conclusion
Different cytogenomic tools are crucial to delineate breakpoints and the involved genes. FISH technique allows the proper characterization of suspected chromosomal abnormalities on its chromosome site, whereas array CGH identifies the exact copy number changes with the involved genes, which facilitate genotype/phenotype correlation.