Abstract
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.