Microarray analysis of unbalanced translocation in Wolf-Hirschhorn syndrome.

[wolf-hirschhorn syndrome]

Wolf-Hirschhorn syndrome (WHS ) is caused by deletions involving chromosome region 4 p 16 .3 , which is characterized by growth delay , mild -to -severe mental retardation , hypotonia , facial dysmorphisms and shows extensive phenotypic variability include feeding difficulties , epilepsy and congenital anomalies . Variation in the size of the deletion involving chromosome region 4 p 16 .3 may explain the clinical variation . However , previous studies indicate that duplication for another chromosome region due to an unbalanced translocation elucidate approximately 40 -45 % WHS patients . Therefore , we used whole genomic cytogenetics array to analyze the entire genome at a significantly higher resolution over conventional cytogenetics to characterize the exact subtelomeric aberration region of one patient with developmental delay and several facial characteristics reminiscent Wolf-Hirschhorn syndrome . Here we report that our patient had 3 .7 Mb deletion at the 4 p 16 .2 and 6 .8 Mb duplication at 8 p 23 .1 resulted from the unbalanced translocations der (4 )t (4 ;8 )(p 16 .2 ;p 23 .1 ). We confirmed that our patient with monosomy 4 p 16 .2 which is consistent with Wolf-Hirschhorn syndrome and trisomy 8 p 23 .1 . The combination of the 4 p deletion with 8 p partial trisomy explains the complex phenotype presented by our patient .