[A case of Wolf-Hirschhorn syndrome diagnosed by single nucleotide polymorphism array].

Objective: To explore the genetic causes for a child with multiple congenital malformations and epilepsy through analysis of copy number variations, and to correlate the genotype with the phenotype.

Methods: G-banding karyotyping was performed on the child and her parents. Single nucleotide polymorphisms array (SNP-array) was used to map the exact chromosomal breakpoints in the proband. The result was validated with fluorescence in situ hybridization (FISH).

Results: G banding analysis suggested that the proband had a karyotype of 46,XX,del(4)(p15), while both of his parents had a normal karyotype. SNP-array has identified a hemizygous deletion of 13.3 Mb on chromosome 4p16.3p15.33, which has been implicated in Wolf-Hirschhorn syndrome. FISH assay has confirmed the de novo origin of the deletion, with the karyotype and clinical phenotype of both parents taken into consideration.

Conclusion: A case of Wolf-Hirschhorn syndrome has been diagnosed by clinical manifestation and karyotyping analysis. Compared with conventional karyotyping analysis, SNP-array has greater resolution and accuracy, and can provide useful information for genetic counseling.