[A case with partial trisomy 7 (q34→qter) derived from a paternal reciprocal translocation t(7;14)(q34;q32)]

To determine the origin of chromosomal aberrants in a mentally retarded children, and to correlate the karyotype with phenotype.

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.

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.

This result suggested that partial trisomy 7q exert mainly phenotypic effect on the patient. Parental karyotype analysis could help define the aberrant type.