Female carriers of balanced translocations involving an X chromosome and an autosome offer genetic counselling challenges. This is in view of the number of possible meiotic outcomes, but also due to the impact of X chromosome-localised genes that are no longer subject to gene silencing through the X chromosome inactivation centre. We present a case where delineation of the extent of X chromosome-localised genes on the derivative autosome using molecular karyotyping offers critical information in the context of genetic counselling.
Keywords: Case report; KAL-1 protein; New Zealand; Receptors, gastrin-releasing peptide; Trisomy; X chromosome inactivation; X chromosome, monosomy Xp22 pter.