A Familial Case of 1q31.2q32.2 Deletion with No Phenotypic Presentation.

Introduction: Deletions of the interstitial region of chromosome 1q are rare and associated with clinical features including growth restriction, developmental delays, and dysmorphic features. Here, we describe an asymptomatic family with an interstitial 1q31 deletion found incidentally.

Case presentation: A 42-year-old male presented with concerns for colonic polyps and underwent multigene panel analysis for hereditary tumor predisposition syndromes which identified a full-gene deletion of CDC73.

Conclusion: Microarray analysis of peripheral blood DNA showed a 6.9-Mb heterozygous deletion of 1q31.2q32.2 encompassing 33 genes in both proband and daughter. The absence of symptoms, including any autosomal dominant conditions associated with variants in this region, has been identified in only 1 case report while most other cases of 1q31 deletions report a range of clinical presentations. Further description of 1q31 deletions is essential to the development of genotype-phenotype interpretation and to decrease the uncertainty of care recommendations for patients and their families.