A pregnancy following PGD for X-linked dominant [correction of X-linked autosomal dominant] incontinentia pigmenti (Bloch-Sulzberger syndrome): case report.

Incontinentia Pigmenti (Bloch-Sulzberger syndrome) is a rare multisystem, ectodermal disorder associated with dermatological, dental and ocular features, and in <10% of cases, severe neurological deficit. Pedigree review suggests X-linked dominance with lethality in affected males. Presentation in female carriers is variable. Following genetic counselling, a mildly affected female carrier diagnosed in infancy with a de novo mutation was referred for preimplantation sexing, unusually selecting for male gender, with an acceptance of either normality or early miscarriage in an affected male. Following standard in-vitro fertilization and embryo biopsy, fluorescence in situ hybridization (FISH) unambiguously identified two male and two female embryos. A single 8-cell, grade 4 male embryo was replaced. A positive pregnancy test was reported 2 weeks after embryo transfer, although ultrasonography failed to demonstrate a viable pregnancy. Post abortive fetal tissue karyotyping diagnosed a male fetus with trisomy 16. This is an unusual report of preimplantation genetic diagnosis (PGD) being used for selection of males in an X-linked autosomal dominant disorder and demonstrates the value of PGD where amniocentesis or chorion villus sampling followed by abortion is not acceptable to the patient. This case also demonstrates the importance of follow-up prenatal diagnosis.