De Grouchy Syndrome (18q Deletion): A Rare Case with Clinical and Genetic Insights

De Grouchy syndrome is a rare chromosomal disorder caused by the deletion of the long arm of chromosome 18, involving a critical region that results in a variable phenotype characterized by growth delay, multisystem malformations, and intellectual disability. We report the case of a 7-month-old male presenting with recurrent respiratory infections. Clinical examination revealed multiple craniofacial and musculoskeletal abnormalities, including tapering fingers, clinodactyly of the right thumb and index finger, bilateral Simian creases, and long toes with overriding of the fourth toe over the fifth. Diagnostic imaging suggested bilateral cryptorchidism and mild ventriculomegaly. Karyotyping confirmed 18q deletion syndrome with the karyotype 46, XY, del(18)(q21.1). This case highlights the broad clinical spectrum of De Grouchy syndrome and emphasizes the importance of precise molecular mapping for genotype–phenotype correlation, early diagnosis, and timely intervention and management.