PROJECT SUMMARY/ABSTRACT
Germline PTEN mutations cause PTEN hamartoma tumor syndrome (PHTS), a hereditary overgrowth and cancer
predisposition disorder. Besides being a classical tumor suppressor gene associated with cancer, PTEN mutations are one
of the most common causes of neurodevelopmental disorders, including autism spectrum disorder (ASD) and developmental
delay (DD). However, it is not known which specific PHTS individual will develop ASD/DD, and importantly, whether all
children with PHTS and ASD/DD grow up to have identical cancer risks as non-ASD/DD PHTS. The broad over-arching
objective of this proposal is to systematically characterise the modifier landscape of individuals with PHTS in order to
ultimately shift current research and clinical practice paradigms from population-level probabilities towards more precise
individual-level disease risk probabilities. Based on the current knowledge gaps and proof-of-principle data, the central
hypothesis is that interactions of germline PTEN variation with other pertinent measurable biological factors, such as
germline genomic modifiers or metabolic differences, provide more precise risk estimates of ASD/DD and possibly,
comorbid cancer in PHTS at the individual level. This hypothesis will be tested through three specific aims: (Aim 1) To
identify metabolomic markers of ASD/DD and cancer risk in PHTS patient-derived plasma and lymphoblastoid cell lines;
(Aim 2) To characterize genomic markers of ASD/DD and cancer risk in PHTS via multimodal phenotype-driven genomic
analyses including copy number variation analysis, family-based whole-genome sequencing, and genome-wide derivation
of polygenic risk scores; (Aim 3) To generate a predictive model of ASD/DD and cancer risk in PHTS including translational
methods to facilitate clinical adoption for individual patient risk stratification. This patient-focused research will rely on an
existing uniformly phenotyped PHTS cohort and continuing prospective accrual of individuals harboring germline PTEN
mutations. The proposed research aligns with the NICHD Priorities and the Interagency Autism Coordinating Committee
strategic plan for ASD in that the priority is (1) to understand genetic syndromes associated with ASD and the co-occurring
medical and mental health conditions associated with such disorders; (2) to identify reliable markers to predict for ASD
within PHTS in a timely manner, since earliest interventions lead to improved outcomes in ASD; (3) to understand the
biology of autism through investigating metabolomic and genomic markers and importantly, integrating these factors
through predictive model development. The proposed research is innovative because in addition to studying a monogenic
(less heterogeneous) and deeply/uniformly phenotyped group of individuals with PTEN-ASD/DD, this proposal goes
beyond observational epidemiological interrogation into investigating underlying metabolomic and genomic factors that
contribute first to altered ASD/DD and then comorbid cancer risks in individuals with ASD/DD. Upon conclusion, in
addition to discovery science, this application is projected to result in predictive methods that clinicians can adopt at the
point-of-care.