This study presents prenatal diagnosis and genetic analysis of a pedigree with X-linked intellectual disability. A gravida at approximately 20 gestational weeks underwent prenatal diagnosis following non-invasive prenatal testing suggested sex chromosome abnormalities. Copy number variation (CNV) sequencing identified a 5.7 Mb duplication at Xp22.2p22.11 in the fetus, which initially classified as a variant of uncertain clinical significance. This duplication was inherited from the phenotypically normal mother, while paternal CNV results were normal. Genetic testing of four intellectually disabled family members revealed the identical 5.7 Mb duplication. Through expanded pedigree analysis, the pathogenicity classification of the Xp22.2p22.11 microduplication was upgraded to likely pathogenic. After comprehensive genetic counseling, the family elected pregnancy termination with informed consent.

This study presents prenatal diagnosis and genetic analysis of a pedigree with X-linked intellectual disability. A gravida at approximately 20 gestational weeks underwent prenatal diagnosis following non-invasive prenatal testing suggested sex chromosome abnormalities. Copy number variation (CNV) sequencing identified a 5.7 Mb duplication at Xp22.2p22.11 in the fetus, which initially classified as a variant of uncertain clinical significance. This duplication was inherited from the phenotypically normal mother, while paternal CNV results were normal. Genetic testing of four intellectually disabled family members revealed the identical 5.7 Mb duplication. Through expanded pedigree analysis, the pathogenicity classification of the Xp22.2p22.11 microduplication was upgraded to likely pathogenic. After comprehensive genetic counseling, the family elected pregnancy termination with informed consent.