Background: Short arm deletions of the X-chromosome are challenging issues for genetic
counseling due to their low penetrance in population. Female carriers of these deletions have milder
phenotype than male ones, considering the intellectual ability and social skills, probably because of
the X-chromosome inactivation phenomenon.
Case report: A female patient with a 10Mb distal Xp deletion and an Xq duplication, showing mild
intellectual disability, is described in this report. While the deletion arose from a maternal pericentric
inversion, the duplication was directly transmitted from the mother who is phenotypically normal.
Conclusion: This report underlines the usefulness of molecular cytogenetic technics in postnatal diagnosis.