Complex phenotype with social communication disorder caused by mosaic supernumerary ring chromosome 19p

Background Deletions or duplications of chromosome 19 are rare and there is no previous report in the literature of a ring chromosome derived from proximal 19p. Copy Number Variants (CNVs) responsible for complex phenotypes with Social Communication Disorder (SCD), may contribute to improve knowledge about the distinction between intellectual deficiency and autism spectrum disorders. Case presentation We report the clinical and cytogenetic characterization of a patient (male, 33 years-old, first child of healthy Portuguese non-consanguineous parents) presenting with a complex phenotype including SCD without intellectual deficiency and carrying a mosaic supernumerary ring chromosome 19p. Microarray-Based Comparative Genomic Hybridization and Fluorescence in situ Hybridization were performed. Genetic analysis showed a large mosaic interstitial duplication 19p13.12p12 of the short arm of chromosome 19, spanning 8.35 Mb. Our data suggested a putative association between psychosocial dysfunction and mosaic pure trisomy 19p13.2p12. Conclusion This clinical report demonstrated the need to analyze more discreet trait-based subsets of complex phenotypes to improve the ability to detect genetic effects. To address this question and the broader issue of deciphering the yet unknown genetic contributors to complex phenotype with SCD, we suggest performing systematic psychological and psychiatric assessments in patients with chromosomal abnormalities.