Additional patients with 4q deletion: Severe growth delay and polycystic kidney disease associated with 4q21q22 loss.

Background: To the best of our knowledge, this is the third report concerning 4q21q22 deletions. In this report, we describe the cases of two girls with 4q deletion and polycystic kidney disease. G-banding confirmed the deletion in one patient but not in the other.
Methods: We describe the cases of two girls with 4q deletion and polycystic kidney disease. Chromosomal deletions were mapped to 4q21-22. One patient had a simple 4q contiguous gene deletion, whereas the other patient had a complicated chromosomal rearrangement. In patient 1, a smaller part of the 4q deletion was translocated to the 3p region.
Results: Fifty-four genes and 72 genes were deleted in patients 1 and 2, respectively. In both patients, 52 genes were consistently deleted.
Conclusion: The present two patients had a similar phenotype, including severe growth and developmental retardation, and a characteristic facial appearance. The loss of RPKG2 and RASGEF1B causes severe growth defect. PKD2 loss causes kidney cysts.
(© 2015 Japan Pediatric Society.)