Molecular Cytogenetic Analysis of Recombinant Chromosome 8 in a Child with Developmental Delay and Dysmorphic Features: A Case Report from India and Literature Review

Abstract

Recombinant chromosome 8, rec(8) is associated with a syndrome, often reported in individuals of Hispanic ancestry, characterized by moderate-to-severe intellectual disability, craniofacial dysmorphism, and congenital heart or urogenital anomalies. It typically results from a parental pericentric inversion on chromosome 8, with constant breakpoints at 8p23.1 and 8q22.1 in Hispanic population and variants in other populations. We describe a 1.5-year-old Indian patient with a milder rec(8) variant. Unlike the classic Hispanic presentation, this child showed partial phenotype overlap with developmental delay and craniofacial dysmorphism but no cardiac or urogenital defects. The father’s inversion produced rec(8) with breakpoints at 8p23.1 and 8q22.3. Array comparative genomic hybridization confirmed partial monosomy 8p and trisomy 8q, with a 7.6Mb deletion on cytoband 8p23.3p23.1 and a 43.3Mb duplication on cytoband 8q22.3q24.3. These del/dup segments overlapped but were smaller than original rec(8) cases of Hispanic origin. Follow-up revealed intellectual disability and seizures. The comparison of our case with three prior reports highlights shared clinical features associated with overlapping chromosomal breakpoints. Regular neurodevelopmental screening may help assess morbidity in this Indian variant.