Objective: To determine the origin of chromosomal aberrants in a mentally retarded children, and to correlate the karyotype with phenotype.
Methods: Routine G-banding were performed to analyze the karyotype of the patient and her parents, and array comparative genomic hybridization (array CGH) were used for finely mapping the aberrant regions.
Results: The mother had a normal karyotype. The father had an apparently balanced translocation involving chromosome 7q and 14q, the karyotype was 46, XX, t(7;14) (q34;q32), the karyotype of the child was then ascertained as 46, XX, der(14) t(7;14) (q34;q32.33) pat. Array CGH finely mapped the duplication to 7q34-qter, a 17.09 Mb region, and a very small associated deletion of distal chromosome 14 to 14q32.33-qter, a 2.27 Mb region. The patient presented some frequently seen features in partial trisomy 7q cases such as mental retardation, low birth weight, small nose, cleft palate, low-set ears and short neck.
Conclusion: This result suggested that partial trisomy 7q exert mainly phenotypic effect on the patient. Parental karyotype analysis could help define the aberrant type.