Parents

KCNK9 imprinting syndrome is an extremely rare genetic disorder characterized by a variety of symptoms including distinctive facial features, varying degrees of intellectual disability, and congenital hypotonia. KCNK9 imprinting syndrome is caused by an alteration in the maternal copy of the KCNK9 gene. The alteration in the KCNK9 gene that causes this disorder is usually a de novo alteration in the maternal copy of the gene. This means that the change in the gene occurred randomly and was not passed on from a parent, so the likelihood of another child in the family having the disorder is extremely low. This disorder involves genetic imprinting. Everyone has two copies of nearly every gene – one received from the father and one received from the mother. In most cases, both genes are “turned on” or active. However, some genes are preferentially silenced or “turned off” based upon which parent that gene came from (genetic imprinting). Genetic imprinting is controlled by chemical switches through a process called methylation. Proper genetic imprinting is necessary for normal development. With the KCNK9 gene, the copy received from the father is turned off or silenced. An alteration in this gene from the father is not associated with any consequences to the child, but it can be passed to his daughters, who would then be at risk to have affected children. The copy received from the mother is normally turned on. An alteration to the maternal copy of this gene leads to KCNK9 imprinting syndrome.