Proximal 4p Deletion Syndrome in a Woman With Developmental Delay: A Case Report and Literature Review

Deletions in chromosome 4p can lead to two distinct phenotypes, Wolf-Hirschhorn syndrome (WHS) and proximal 4p deletion syndrome. While WHS, associated with distal deletions, has well-characterized phenotypic features, proximal 4p deletion syndrome, involving the 4p14-p 16.1 region, shows milder manifestations, and its causative gene remains unknown with fewer reported cases. Here we report a Chinese case: a 21-year-old female with a peripheral blood chromosomal karyotype of 46,XX,del(4)(p15.3-p16). NGS-CNVA further revealed an 11.7 Mb deletion in the 4p16.2-p15.32 region and a 1.25 Mb microduplication in 16p13.13. She had ovarian dysfunction, and mild mental retardation without typical proximal 4p deletion phenotypes. Through analysis of Genecards and OMIM databases, we identified two genesneurodevelopmental genes DRD5 and WFS1, and four ovarian dysfunction-related genes WFS1, CC2D2A, PROM1, and QDPR, suggesting their roles in the patient's manifestations. Additionally, a review of 38 published cases of proximal 4p deletion syndrome revealed 21 cases with an overlap in the deleted region with our case. This report not only enhances the recognition of this rare syndrome among clinicians but also provides a basis for further exploration of the potential causative genes, contributing to a better understanding of the genotype-phenotype correlations in proximal 4p deletion syndrome.