Late-onset Proteus syndrome with cerebriform connective tissue nevus and subsequent development of intraductal papilloma.

Proteus syndrome (PS) is a rare segmental overgrowth disorder caused by a mosaic activating variant in AKT1. The features of PS are often not present at birth but develop during the first few years of life. We describe a 55-year-old female, whose first symptom of overgrowth, a cerebriform connective tissue nevus, occurred at 19 years of age. We report the identification of the AKT1 c.49G > A p.(Glu17Lys) variant in this progressive lesion, the bony overgrowth, and recurrence after surgical intervention. In the sixth decade of life, this individual developed intraductal papillomas within her right breast which were confirmed to contain the same activating AKT1 variant as the connective tissue nevus. While similar neoplasms have been described in an individual with Proteus syndrome, none has been evaluated for the presence of the AKT1 variant. The tumor also contained two likely pathogenic variants in PIK3R1, c.1392_1403dupTAGATTATATGA p.(Asp464_Tyr467dup) and c.1728_1730delGAG p.(Arg577del). The finding of additional genetic variation putatively affecting the PI3K/AKT pathway in the neoplastic tissue may provide preliminary evidence of a molecular mechanism for tumorigenesis in PS. The late onset of symptoms and molecular characterization of the breast tumor expand the clinical spectrum of this rare disorder.

A systematic literature review of disclosure practices and reported outcomes for medically actionable genomic secondary findings.

PURPOSE: Secondary findings (SFs) are present in 1-4% of individuals undergoing genome/exome sequencing. A review of how SFs are disclosed and what outcomes result from their receipt is urgent and timely. METHODS: We conducted a systematic literature review of SF disclosure practices and outcomes after receipt including cascade testing, family and provider communication, and health-care actions. Of the 1,184 nonduplicate records screened we summarize findings from 27 included research articles describing SF disclosure practices, outcomes after receipt, or both. RESULTS: The included articles reported 709 unique SF index recipients/families. Referrals and/or recommendations were provided 647 SF recipients and outcome data were available for 236. At least one recommended evaluation was reported for 146 SF recipients; 16 reports of treatment or prophylactic surgery were identified. We found substantial variations in how the constructs of interest were defined and described. CONCLUSION: Variation in how SF disclosure and outcomes were described limited our ability to compare findings. We conclude the literature provided limited insight into how the American College of Medical Genetics and Genomics (ACMG) guidelines have been translated into precision health outcomes for SF recipients. Robust studies of SF recipients are needed and should be prioritized for future research.