Further delineation of 17p13.3 microdeletion involving CRK. The effect of growth hormone treatment.

Recently, a 17p13.3 microdeletion syndrome characterized by significant postnatal growth retardation, mild to moderate mental retardation and facial dysmorphic manifestations has been delineated to a small region within the area of the Miller-Dieker syndrome critical region. We report a boy with a 284 kb deletion within the Miller-Dieker critical region including CRK, but not involving YWHAE and TUSC5. He showed mental retardation and had significant postnatal growth retardation. Further, he had slight facial and limb abnormalities. Cerebral MRI, including visualization of the pituitary gland, disclosed no abnormalities. The findings in the present case indicate, that CRK may also be involved in the facial phenotype of the 17p13.3 microdeletion syndrome, and that CRK, and not YWHAE, seems to be involved in limb malformations. The effect of growth hormone treatment in CRK-deficient children is discussed.