Terminal 4q duplication and extended 10q deletion in a preterm infant with linear growth restriction: transcriptomic evidence of disrupted developmental and metabolic pathways.

Background: Distal duplication 4q syndrome and distal 10q26 deletion syndrome are rare chromosomal abnormalities associated with complex and overlapping phenotypes. Most cases result from unbalanced inheritance of a parental translocation, yet the specific contributions of each chromosomal segment to the clinical phenotype remain poorly defined. Case presentation: We report on a male preterm infant born at 28 + 6 weeks' gestation who carried a derivative chromosome 10 due to a paternally inherited unbalanced translocation t(4;10)(q31.22;q26.13), leading to a 42.46 Mb duplication of 4q31.22-q35.2 and a 10.77 Mb deletion of 10q26.13-q26.3. The patient presented with severe postnatal linear growth restriction, delayed neurodevelopment, a giant umbilical hernia, bilateral renal hypoplasia, and relative overweight. Thumb anomalies were absent. Methods: Genetic analyses included chromosomal microarray, conventional karyotyping, fluorescence Results: Gene expression analysis confirmed reduced expression of established 10q26-related genes, including Conclusion: This case illustrates how extended terminal deletions of 10q can disrupt key structural and metabolic gene networks. To our knowledge, this is the first transcriptomic characterization of a 10.77 Mb deletion in the 10q26.13-q26.3 region together with a large terminal 4q duplication. Integrating functional transcriptomics with clinical and cytogenetic data may enhance our understanding of rare chromosomal disorders and inform individualized management, including reproductive counseling and longitudinal clinical follow-up.