[Paternally originated Wolf-Hirschhorn syndrome detected by multiplex ligation-dependent probe amplification and...

To confirm the diagnosis of a Wolf-Hirschhorn syndrome by family study using both cytogenetic and molecular genetic techniques.

G-band karyotyping was performed for all the 6 members in the family. Multiplex ligation-dependent probe amplification (MLPA) was used to detect the chromosome abnormality for the proband, his father and brother. Microarray comparative genomic hybridization (Array-CGH) was carried out to map the exact chromosomal breakpoints for the proband.

The proband presented with a typical face, delayed growth and hypotonia in Wolf-Hirschhorn syndrome. His G-band karyotype was 46, XY, der(4)t(4;8) (p16.2; p23.1)pat. MLPA showed 4pter loss and 8pter gain. Array-CGH revealed an XY male with a 3.781 Mb deletion of 4p16.3-p16.2 and a 6.760 Mb duplication of 8p23.3-p23.1. The proband's brother has mental retardation and skeletal abnormalities. His G-band karyotype was 46, XY, der(8)t(4;8)(p16.2;p23.1)pat. MLPA showed 4pter gain and 8pter loss. The proband's father had normal phenotype with a balanced translocation of 46, XY, t(4;8)(p16.2;p23.1)pat. MLPA showed a normal result. The proband's grandfather showed a normal phenotype with a balanced translocation 46, XY, t(4;8)(p16.2;p23.1). The other members in the family showed normal phenotypes with normal karyotypes.

The proband has features of Wolf-Hirschhorn syndrome with partial monosomy 4p and partial trisomy 8p. The proband's brother has a partial trisomy 4p and partial monosomy 8p. The derived chromosomes are inherited from paternal balanced translocation t(4;8)(p16.2;p23.1).