A newborn infant presents with a distinctive high-pitched, cat-like cry, microcephaly, and severe intellectual disability. Genetic analysis is most likely to reveal which of the following?

Explanation

The clinical features described, particularly the distinctive high-pitched, cat-like cry (due to laryngeal abnormalities), microcephaly, and severe intellectual disability, are classic manifestations of Cri-du-chat syndrome. This syndrome is caused by a partial deletion of the short arm of chromosome 5, often designated as 5p deletion. Trisomy 18 (Edwards syndrome) presents with different features like rocker-bottom feet, clenched hands, and severe heart defects. Translocation between chromosomes 11 and 22 is associated with Ewing sarcoma. Duplications of chromosome 7 are rare and present with variable phenotypes.