Familial Translocation t(2;4) (q37.3;p16.3), Resulting in a Partial Trisomy of 2q (or 4p) and a Partial Monosomy of 4p (or 2q), Causes Dysplasia

Background: Wolf-Hirschhorn syndrome, a well-known contiguous microdeletion syndrome, is caused by deletions on chromosome 4p. While the clinical symptoms and the critical region for this disorder have been identified based on genotype-phenotype correlations, duplications in this region have been infrequently reported.

Conclusion: Our case report shows that both deletions and duplications of the Wolf-Hirshhorn critical region cause intellectual disability/developmental delay and multiple congenital anomalies.

Case presentation: We report on a family presenting with a set of dysmorphic facial features, attention deficit hyperactivity disorders, learning difficulties, speech and cognitive delays, overgrowth/developmental delay, and musculoskeletal anomalies. Through karyotyping, chromosomal microarray, and PCR analyses, it was found that patients in this family had translocations on chromosomes 2q37 and 4p16. Patients with 2q duplications and 4p deletions showed clinical phenotypes typical of WHS syndrome. Family members with 2q deletions and 4p duplications similarly manifested distinct clinical phenotypes.