Birth of a Healthy Histocompatible Sibling following Preimplantation Genetic Diagnosis for Chronic Granulomatous Disease at the Blastocyst Stage Coupled to HLA Typing

Abstract

Objective: To perform preimplantation genetic diagnosis (PGD) for chronic granulomatous disease with simultaneous HLA typing in a family case with an affected male child, with the aim of selecting unaffected and HLA-matched embryos to act as donors for hematopoietic stem cell transplantation from umbilical cord blood. Methods: A flexible, indirect HLA haplotyping protocol, based on single-cell multiplex PCR analysis of multiple polymorphic short tandem repeat (STR) markers within the human HLA complex, was optimized for the simultaneous amplification of the informative STR markers together with the gp91-phox gene region containing the mutation and the sexing marker amelogenin. Detection of the c.469C>T disease mutation was performed by minisequencing. Biopsy was performed at the blastocyst stage on day 5 by removal of trophectoderm cells. Results: A total of 11 blastocysts were biopsied on day 5 and a successful result for the informative STR markers and for the mutation detection was obtained for all 11 blastocyst samples. Two healthy and HLA-matched embryos were identified and transferred resulting in a singleton pregnancy. The results of the PGD were confirmed following standard prenatal diagnosis, and cord blood hemopoietic stem cells were obtained from the newborn for subsequent transplantation into the affected sibling. Conclusions: This study demonstrates the feasibility and first successful application of this complex PGD approach as a therapeutic option in families with children affected with X-linked chronic granulomatous disease.